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Original article: Two different profiles of peach allergy in the north of Spain
Allergy
Abstract
Peach allergy has two different patterns: central Europe with oral allergy syndrome (OAS) related to a primary sensitization to birch pollen Bet v 1 and profilins and southern Europe with mostly systemic symptoms, in many cases due to sensitization to lipid-transfer proteins.
Thirty peach-allergic patients with positive skin and food challenge tests and 29 control subjects were included. Skin prick tests (SPT) with inhalant allergens, commercial peach and apple extracts and native Pru p 3 were performed. In vitro specific immunoglobulin (Ig) E to grass pollen, birch pollen, peach, apple, rBet v 1, rBet v 2 and rPhl p 12 was determined by CAP, and rBet v 1, rMal d 1, rMal d 4, rMal d 3 and rPru p 3 using the ADVIA-Centaur platform. Basophil activation test (BAT) with commercial peach extract, commercial apple extract, nPru p 3, rMal d 3, rMal d 1 and rMal d 4 was also performed.
Pru p 3 was the major allergen in the patient group from northern Spain. Sensitization to this allergen was found in 100% of the patients with systemic symptoms or contact urticaria. Only 60% of OAS patients were sensitized to Pru p 3, being all of them sensitized to profilins and 60% of them to allergens of the Bet v 1 family. Specific IgE determination and BAT using recombinant allergens (rPru p 3) show specificity and sensitivity values close to 100%.
Most peach-allergic patients coming from the north of Spain present systemic symptoms after ingestion of peach, Pru p 3 being the main allergen. Patients with OAS present profilin-Bet v 1-related sensitization. Thus, in the north of Spain our patients show a mixed central-south Europe pattern with LTP-profilin-Bet v 1 sensitization depending on the symptoms presented. The use of natural and recombinant plant allergens, allows establishing the sensitization patterns to the different allergens studied.
... Various studies have assessed the utility of BAT to diagnose allergy to different foods since the first publication of the kind by Moneret-Vautrin et al. 45 Studied foods include cow's milk, 46,47 egg, 46,48 wheat, 49-53 peanut, 4,22,48,54,55 hazelnut, 56-59 shellfish 60 and peach, [61][62][63] apple, 64 celery and carrot. 65,66 Generally, these studies showed that BAT has good sensitivity and specificity (Table 2) CD3 is expressed on T cells and therefore allows the exclusion of this cell type when using CCR3 or CRTH2. ...
... The diagnostic performance of BAT is allergen specific and can vary with the allergen preparation used for cell stimulation in the assay. The use of individual allergens in the BAT has also been tested, for example using lipid transfer proteins (e.g., Pru p 3 from peach 62 and Ara h 9 from peanut 39 ), seed storage proteins (e.g., Ara h 1, Ara h 2, Ara h 3 and Ara h 6 from peanut 39 ) and Bet v 1 homologues (e.g., Ara h 8 from peanut 67 ). In these studies, BAT using single allergen components showed to be advantageous compared to BAT using food extracts to diagnose allergy to some foods (e.g., BAT to Pru p 3 to diagnose peach allergy) but not to others (e.g., BAT to casein to diagnose cow's milk allergy)- BAT to cow's milk showed to be useful in identifying patients who had resolved their cow's milk allergy. ...
... ,62 The use of single allergens has, however, the disadvantage of missing the contribution of minor allergens that are clinically relevant for some patients and of missing the combined effect of multiple allergens to which polysensitized patients produce IgE and which may increase the degree of basophil activation detected in the BAT.Due to its high specificity, which reaches 100% in some studies, 4,48 a positive BAT allows confirming the diagnosis of IgEmediated food allergy with a high degree of certainty. Given the practical implications involved in the performance of the BAT and the fact that in some patients an allergy-focused clinical history together with the documentation of specific IgE to extracts or components is sufficient to confirm or exclude the ...
The diagnosis of IgE-mediated food allergy based solely on the clinical history and the documentation of specific IgE to whole allergen extract or single allergens is often ambiguous, requiring oral food challenges (OFC), with the attendant risk and inconvenience to the patient, to confirm the diagnosis of food allergy. This is a considerable proportion of patients assessed in Allergy clinics. The basophil activation test (BAT) has emerged as having superior specificity and comparable sensitivity to diagnose food allergy, when compared with skin prick test and specific IgE. BAT, therefore, may reduce the number of OFC required for accurate diagnosis, particularly positive OFC. BAT can also be used to monitor resolution of food allergy and the clinical response to immunomodulatory treatments. Given the practicalities involved in the performance of BAT, we propose that it be applied for selected cases where the history, skin prick test and/or specific IgE are not definitive for the diagnosis of food allergy. In the cases that the BAT is positive, food allergy is sufficiently confirmed without OFC; in the cases that BAT is negative or the patient has non-responder basophils, OFC may still be indicated. However, broad clinical application of BAT demands further standardisation of the laboratory procedure and of the flow cytometry data analyses, as well as clinical validation of BAT as a diagnostic test for multiple target allergens and confirmation of its feasibility and cost-effectiveness in multiple settings. This article is protected by copyright. All rights reserved.
... In northern Italy, another group reported sensitization to Pru p 1 of 42.8% and to Pru p 4 of 12.7%, while in southern Italy no positives cases were found. 26 In contrast to other studies carried out in Spain, we did not find serum specific IgE antibodies to PR-10 allergens quantified with Pru p 1. 27 In line with other reports, data in our study group showed that 19% of cases were sensitized to Pru p 4 with no differences between anaphylaxis and OAS subgroups. 26,27 Pru p 7 may have a role, particularly in cases of peach anaphylaxis that are negative to Pru p 3. 28 However, in our study no association was found with cases positive to cypress pollen. ...
... 26 In contrast to other studies carried out in Spain, we did not find serum specific IgE antibodies to PR-10 allergens quantified with Pru p 1. 27 In line with other reports, data in our study group showed that 19% of cases were sensitized to Pru p 4 with no differences between anaphylaxis and OAS subgroups. 26,27 Pru p 7 may have a role, particularly in cases of peach anaphylaxis that are negative to Pru p 3. 28 However, in our study no association was found with cases positive to cypress pollen. 29 Although our cases were not challenged with peach fruit, the consistent and repeated history of allergic reactions and positive skin tests strongly supported the diagnosis of peach allergy. ...
The most important peach fruit allergen is Pru p 3, followed by Pru p 1, Pru p 4, and Pru p 7. We aimed to assess their role in subjects with peach fruit-induced allergy (anaphylaxis and OAS) and compare skin prick tests (SPT) vs. specific immunoglobulin E (sIgE) for predicting anaphylaxis. We also selected a control group. SPT included prevalent inhalant and plant food allergens plus peach peel extract. The sIgE to Pru p 1, Pru p 3, Pru p 4, and Pru p 7 were quantified. Compared with controls (n = 42), cases (n = 41) were younger (P = 0.003), more frequently female (P < 0.05) and had higher SPT positivity to peach peel (44% vs. 2.4%, P < 0.0001). There were significant differences in sensitization to several pollens: Olea europaea, Artemisia vulgaris, Prunus persica, Platanus acerifolia (all P < 0.001); and fruits: apple (P < 0.04), peanut (P < 0.002), tomato (P < 0.005), and melon (P < 0.05). Pru p 3 sIgE was detected in 61% of all cases (85% anaphylaxis and 38% OAS; P < 0.01 each) and 5% of controls (P < 0.001). Pru p 4 sIgE was present in 19% of cases and 7% of controls. The sIgE to Pru p 1 and Pru p 7 were not found. The odds ratio to predict anaphylaxis for peach peel SPT was 113 (confidence interval [CI], 20-613; P < 0.0001); for sIgE to Pru p 3, 22 (CI, 5.3-93; P < 0.0001); and for SPT positivity to selected plant food allergens, 5 (CI, 1-19; P < 0.05). In our study group, SPT with peel peach extract was a better predictor of anaphylaxis than Pru p 3 sIgE or other variables considered. The role of sIgE to Pru p 1, Pru p 4, and Pru p 7 seemed negligible.
... In peach allergy, BAT to Pru p 3 has also shown to be superior to BAT to peach extract, possibly due to the presence of cross-reactive allergens in the extract and the fact that Pru p 3 seems to be the primary sensitizer and the main inducer of effector cell activation in allergy to peach, at least in Southern Europe. 74,75 After initial studies by Commins et al 76 showing basophil activation coinciding with allergic reactions to alpha-gal during OFC to red meat, Mehlich et al 77 studied the diagnostic utility of BAT to alpha-gal and pork kidney in identifying clinically relevant sensitization to this carbohydrate. BAT can also be used ad hoc to diagnose allergy to unusual allergens, such as beer or cannabis, as recently reported. ...
... 86 Of the children who have a confirmed IgE-mediated allergy, the decision to help guide assessment of tolerance often involves confirmation via an OFC, which remains the gold standard for food allergy diagnosis. The timing of when is best to rechallenge a patient is important yet difficult to standardize in terms Cow's milk 80 >6% %CD63þ basophils 81 Ovalbumin to diagnose egg allergy 81 5% %CD63þ basophils 100 Peanut 10 4.78% %CD63þ basophils 100 Ara h 2 to diagnose peanut allergy 73 65.19% maximal %CD63 to Ara h 2/anti-IgE 100 Sesame 71 10.9% %CD63þ basophils 94 Cashew nut 70 5.5% %CD63þ basophils 91 Pistachio nut 70 5.8% %CD63þ basophils 74 Walnut 70 6.4% %CD63þ basophils 92 Pecan 70 2.7% %CD63þ basophils 75 Hazelnut 72 CD-sens>1.7 89 Pru p 3 to diagnose peach allergy 75 >20% CD63þ basophils 96 rTri a 19 to diagnose IgE-mediated wheat allergy 82 >7.9% CD203cþ basophils 81 Salmon 83 0.54 ratio of %CD203cþ basophils to allergen and anti-IgE 85 PPV was estimated from prevalence and sensitivity when not reported in the respective study. ...
The diagnosis of food allergy can have a major impact on the lives of patients and families, imposing dietary restrictions and limitations on social activities. On the other hand, misdiagnosis can place the patient at risk of a potentially severe allergic reaction. Therefore, an accurate diagnosis of food allergy is of utmost importance. The diagnosis of food allergy is often established by the combination of the clinical history and allergen-specific IgE; however, without a clear history of an allergic reaction, the interpretation of IgE sensitization tests can be difficult. There are also rare cases of clinical food allergy in the absence of IgE sensitization. For that reason, testing for suspected food allergy ideally requires access to oral food challenges (OFCs), which are currently the gold standard tests to diagnose food allergy. As OFCs are time consuming and involve the risk of acute allergic reactions of unpredictable severity, the question remains: how can we improve the accuracy of diagnosis before referring the patient for an OFC? Herein, we review the predictive value of different tests used to support the diagnosis of food allergy, discuss implications for therapy and prognosis, and propose a diagnostic approach to be applied in clinical practice.
... 27 Peaches have two different sensitization routes. Allergy to peach in Northern and Central Europe is primarily associated with the oral allergy syndrome caused by sensitization to birch pollen and labile proteins known as profilins, like Bet v 1 and Bet v 2, due to cross-reactivity between pollen profilin and the peach profilin Pru p 4. 28,29 Profilins cross-react with homologous proteins in fruits from the Rosaceae family, like peach, apple and apricot. 30 Peach allergy is the most common food allergy among adults in Southern Europe. ...
... 32 In Southern Europe, peach allergy is primarily mediated by Pru p 3, a lipid transfer protein (LTP). 28 LTPs are widespread plant food pan-allergens that are stable (due to being heatresistant and pepsin-resistant) and are highly conserved proteins of around 10 kD. 33,34 Especially the peach surface fuzz have large amounts of LTP, but also the peel and cutin layers of peaches are rich in proteins and have a higher allergenicity than the pulp with its high carbohydrate content. ...
Background
Naturally‐derived cosmetic product ingredients of both plant and animal origin are increasingly being included in product formulations in order to cater to consumer preferences. They may be an overlooked cause of reactions to cosmetic products in some patients with dermatitis.
Objectives
To identify naturally‐derived cosmetic product ingredients with allergenic potential (type I and type IV) and propose a cosmetic screening test series.
Methods
The study was conducted in two steps. The first step was a market survey using a non‐profit application helping consumers avoid problematic substances in cosmetic products. The application contained 10舁067 cosmetic products that were label checked for naturally‐derived cosmetic product ingredients. The second step was a literature search to examine how frequently the naturally‐derived ingredients were described and related to allergic reactions in cosmetics or other topically administered products.
Results
We identified 121 different naturally‐derived cosmetic product ingredients that were included in at least 30 cosmetic products. In total, 22 ingredients were selected for a screening test series.
Conclusions
We propose a supplemental patch test and a prick test screening series with naturally‐derived cosmetic product ingredients for patients with skin reactions to cosmetic products, aiming to identify a cause in more patients than is currently possible.
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... białek transportujących lipidy (LTP), które są odpowiedzialne za występowanie reakcji układowych. Występowanie alergii zależnej od Pru p 3 związane jest z rzadszym występowaniem brzozy w tej części kontynentu [5]. ...
... 3 Regiony Europy sklasyfikowane przez ONZ. 4 Dodano badania z Turcji. 5 Dla badań obejmujących kilka krajów europejskich i wykazujących dane szacunkowe, gdzie nie było możliwe określenie rozpowszechnienia dla poszczególnych krajów. roślinne i zwierzęce) i jest oceniana jako wątpliwa u 50% chorych z nadwrażliwością na białka pochodzenia zwierzęcego [20]. ...
Diagnosis of allergic diseases is one of the most difficult in medicine. Detailed gathering of a medical history, especially if it concerns food allergy is a big challenge, among others due to the amount and variety of food intake, the presence of cofactors, or the use of food additives. The problem is also the presence of the so-called hidden allergens. Diagnostic process is also complicated by the lack of precise research tools, which are characterized by 100% sensitivity and specificity. Each of the methods used has its limitations, and the negative result is not the basis for the exclusion of allergies. The article presents problems that may be encountered by a doctor diagnosing allergic diseases. The authors hope that it will be helpful, especially in those patients whose clinical manifestations do not correlate with the results of the tests. The more so that allergic diseases are an increasing problem that af-fects not only the patient himself, but they also constitute a social and economical problem. The symptoms of allergic diseases are so troub-lesome for patients that they have been combined into one disease entity known as: allergic irritability syndrome
... [7][8][9] Birch pollen-related PR-10 sensitization underlies most cases of peach-induced oral allergy syndrome (OAS) occurring in temperate climates, while sensitization to non-specific lipid transfer proteins (nsLTPs) is predominant in Mediterranean regions and may induce OAS as well as severe reactions. 1,4,[9][10][11] In southern Europe, primary food allergies, including peach allergy (PA), may account for up to 96% of food allergy cases. 1 Sensitization to nsLTPs, either as primary food allergy or as PFS, accounts for most of PA cases in the Mediterranean region. 1,12,13 However, some PA patients have been found to lack sensitization to Pru p 1 (PR-10), Pru p 3 (nsLTP) and ...
... Diagnostic OFC was performed according to ICON and EAACI guidelines18,20 and previous PA studies3,11 if negative SPT and IgE results were discordant with clinical history. Patients who had had a life-threatening reaction to peach during the last 12 months did not undergo OFC, in line with current guidelines.18 ...
Background
Peach is a common elicitor of food allergic reactions. Peach‐induced immediate reactions may occur as benign pollen‐food syndromes, usually due to birch pollen related PR‐10 cross‐reactivity in temperate climates, and as potentially severe primary food allergies, predominantly related to nsLTP Pru p 3 in Mediterranean regions. The newly described peach allergen Pru p 7 has has gained recent attention as a potential peach allergy severity marker. Sensitisation to Pru p 7 and its allergenic homologues of the gibberellin‐related protein family occurs in areas with high Cupressaceae tree pollen exposure.
Objective
We sought to investigate the distribution, clinical characteristics and molecular associations of Pru p 7 sensitisation among subjects with suspected peach allergy in different regions of France.
Methods
Subjects with suspected peach allergy (n=316) were included. Diagnostic workup was performed according to current guidelines, including open food challenge when required. IgE antibody measurements and competition experiments were performed using the ImmunoCAP assay platform.
Results
Sensitisation to Pru p 7 was present in 171 (54%) of all subjects in the study and in 123 of 198 (62%) diagnosed as peach allergic, more than half of whom were sensitised to no other peach allergen. Frequency and magnitude of Pru p 7 sensitisation were associated with the presence of peach allergy, the clinical severity of peach‐induced allergic reactions, and the level of cypress pollen exposure. Cypress pollen extract completely outcompeted IgE binding to Pru p 7. Pru p 7 was extremely potent in basophil activation tests.
Conclusion and Clinical relevance
A subtype of Cupressaceae pollinosis, characterised by Pru p 7 sensitisation, can be an underlying cause of severe peach allergy.
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... Foods generally contain multiple proteins to which individuals may react differently due to exposure of the food to heat (cooking), acid, and proteases (gastrointestinal tract), and most of the identified relevant food allergens are water-soluble glycoproteins [30][31][32][33] . In addition, antibodies may bind to either linear or conformational epitopes within a protein's structure, with the former representing short runs of amino acids within the primary protein structure, and the latter representing epitopes within the three-dimensional structure of the protein. ...
... The allergens most commonly found in peach include Pru P 1 (Bet v 1-homologous pathogenesis related protein 10 [PR 10]), Pru P 2 (thaumatin-like protein), Pru P 3 (lipid transfer protein), Pru P 4 (profilin), and Pru P 7 (antimicrobial peptide Gibberellin-regulated protein: GRB). Among the allergens, lipid transfer protein Pru P 3 is associated with severe peach allergy symptoms 67,68 , while on the other hand, Pru P 1 and Pru P 4 are mostly associated with milder forms of peach allergy (oral allergy symptoms) 32 . It has been suggested that the difference in severity of peach allergy might be related to the physical and chemical structure of the allergens, with Pru P 1 and Pru P 4 easily deactivated by the higher temperature and acidic environment in our gastrointestinal tract, while Pru P 3 is strongly 69 . ...
Food allergy is an increasingly important health problem in the world. Several genome-wide association studies (GWAS) focused on European ancestry samples have identified food allergy-specific loci in the HLA class II region. We conducted GWAS of self-reported reactivity with common foods using the data from 11011 Japanese women and identified shrimp and peach allergy-specific loci in the HLA-DR/DQ gene region tagged by rs74995702 (P = 6.30 × 10-17, OR = 1.91) and rs28359884 (P = 2.3 × 10-12, OR = 1.80), respectively. After HLA imputation using a Japanese population-specific reference, the most strongly associated haplotype was HLA-DRB1*04:05-HLA-DQB1*04:01 for shrimp allergy (P = 3.92 × 10-19, OR = 1.99) and HLA-DRB1*09:01-HLA-DQB1*03:03 for peach allergy (P = 1.15 × 10-7, OR = 1.68). Additionally, both allergies' associated variants were eQTLs for several HLA genes, with HLA-DQA2 the single eQTL gene shared between the two traits. Our study suggests that allergy to certain foods may be related to genetic differences that tag both HLA alleles having particular epitope binding specificities as well as variants modulating expression of particular HLA genes. Investigating this further could increase our understanding of food allergy aetiology and potentially lead to better therapeutic strategies for allergen immunotherapies.
... skin prick test and specific IgE) are its high specificity (reaching 100 % in some studies) and its high positive predictive value, which allow to confirm the diagnosis of food allergy in the case of a positive BAT with a high degree of certainty [61•, 101-103]. BAT can be performed using crude extracts [61•, 101, 104] or single allergens [105][106][107]. Due to the technical and logistical aspects involved in its performance, BAT is often used as a second step in the diagnostic process, only in selected patients in whom the combination of the clinical history and the results of skin prick test and/or specific IgE could not confirm or exclude the diagnosis of food allergy [61•]. ...
... Basophil testing is a safe approach and of great interest in the evaluation of those allergens where specific IgE detection tests are not available; current clinical research questions regarding application of basophil testing are listed in Table 2. Basophil activation tests make a variety of allergen molecules accessible as diagnostic reagents, as they can successfully be performed with drugs [38, 80,[84][85][86][87][88][89][90][91][92][93][94] as well as recombinant venom allergen [153], food allergen [105][106][107] and aeroallergens [33, [154][155][156]. BAT is an important tool for research of allergen molecules inducing activation of basophils by IgE-bridging on these cells. ...
Purpose of Review
We review basophil testing by flow cytometry with an emphasis on advantages and disadvantages.
Recent Findings
There are many tools available to assess the presence and severity of allergic diseases in patients. For 50 years, peripheral blood basophils have been used as tools to study these diseases. It is a very accessible cell that binds IgE antibody and secretes the classical mediators responsible for the symptoms of allergic reactions. In the last decade, an even more accessible methodology, using flow cytometry, has been developed to enhance the ability to use basophils for both mechanistic and clinical diagnostics. Basophil testing has been included in diagnostics for different forms of allergies as well as to monitor disease status.
Summary
A variety of studies have begun to establish both precise methods and their clinical relevance for disease diagnosis, but there remain some important questions on how to take optimal advantage of the behaviours of basophils.
... In addition, some geographical discrepancies have been identified concerning, for example, severe systemic reactions to Pru p 3 in people from Mediterranean countries, compared to people from northern countries [92,93]. However, the risk for a severe allergic response to Pru p 3, was also reported for people living outside the Mediterranean countries [15,94]. ...
Most of the allergenic proteins from fruits identified so far belong to different families of pathogenesis-related (PR) proteins. These PR proteins have been classified in different families of structurally and functionally unrelated proteins, but the majority of all fruit allergens belong to three groups, in particular PR-5 thaumatin-like proteins (TLP), PR-10 Bet v 1-like proteins, and PR-14 non-specific lipid transfer proteins (nsTLP). Some allergenic proteins from fruits can also be found among PR-protein families of PR-2 β1,3-glucanase proteins, PR-3 chitinases I, II, IV–VII, and PR-8 chitinases III. In addition, other important fruit allergens occur in protein families unrelated to the PR-protein families, such as the profilins and the newly emerging group of gibberellin-regulated proteins (GBRP). Finally, proteins that belong to seed storage proteins from higher plants, including 2S albumins, 7S globulins (vicilin), and 11S globulins (legumin), must be retained as possible potential fruit allergens resulting from the unintended consumption of the seeds. Here, we present an overview of the structural organization, functional properties, and phylogenetical relationships among these different groups of fruit allergens, supporting the occurrence of cross-reactivity and cross-allergenicity often described between fruit allergens, and the corresponding allergens from vegetables and pollens.
... FA to non-specific lipid transfer protein (nsLTP), especially to Pru p 3, the major peach allergen, can lead to severe reactions and cross-reactivity with other nsLTPs from numerous foods and pollens, producing a complex clinical pattern: LTP syndrome (4). Food avoidance, as treatment for LTP-allergic patients, is deeply convoluted due to the multi-taxonomic allergenic sources that can trigger an allergic reaction (5). ...
Introduction
Allergen-specific immunotherapy (AIT) is applied as treatment to rise tolerance in patients with food allergies. Although AIT is thoroughly used, the underlying epigenetic events related to tolerant induction are still unknown. Thus, we aim to investigate epigenetic changes that could be related to tolerance in dendritic cells (DCs) from anaphylactic mice to lipid transfer proteins, Pru p 3, in the context of a sublingual immunotherapy (SLIT) with a glycodendropeptide (D1ManPrup3) that has demonstrated tolerant or desensitization responses depending on the treatment dose.
Methods
Changes in DNA methylation in CpG context were determined comparing Sensitized (Antigen-only) animals and two groups receiving SLIT with the D1ManPrup3 nanostructure (D1ManPrup3-SLIT): Tolerant (2nM D1ManPrup3) and Desensitized (5nM D1ManPrup3), against anaphylactic animals. DNA from lymph nodes-DCs were isolated and then, Whole Genome Bisulphite Sequencing was performed to analyze methylation.
Results
Most differentially methylated regions were found on the area of influence of gene promoters (DMPRs). Compared to the Anaphylactic group, the highest value was found in Desensitized mice (n = 7,713 DMPRs), followed by Tolerant (n = 4,091 DMPRs) and Sensitized (n = 3,931 DMPRs) mice. Moreover, many of these epigenetic changes were found in genes involved in immune and tolerance responses (Il1b, Il12b, Il1a, Ifng, and Tnf) as shown by functional enrichment (DCs regulation, B cell-mediated immunity, and effector mechanisms).
Discussion
In conclusion, different doses of D1ManPrup3-SLIT induce different DNA methylation changes, which are reflected in the induction of distinct responses, tolerance, or desensitization.
... In addition to this, it has been reported that profilin could play a role of confounding factors interfering with the severity of the symptoms [37]. In fact, in our previous study, it has been demonstrated that co-sensitization to profilin is causative for less severe reactions in response to LTPs [27]. ...
Plant-food allergy is an increasing problem, with nonspecific lipid transfer proteins (nsLTPs) triggering mild/severe reactions. Pru p 3 is the major sensitizer in LTP food allergy (FA). However, in vivo and in vitro diagnosis is hampered by the need for differentiating between asymptomatic sensitization and allergy with clinical relevance. The basophil activation test (BAT) is an ex vivo method able to identify specific IgE related to the allergic response. Thus, we aimed to establish the value of BAT in a precise diagnosis of LTP-allergic patients. Ninety-two individuals with peach allergy sensitized to LTP, Pru p 3, were finally included, and 40.2% of them had symptoms to peanut (n = 37). In addition, 16 healthy subjects were recruited. BAT was performed with Pru p 3 and Ara h 9 (peanut LTP) at seven ten-fold concentrations, and was evaluated by flow cytometry, measuring the percentage of CD63 (%CD63+) and CD203c (%CD203chigh) cells, basophil allergen threshold sensitivity (CD-Sens), and area under the dose–response curve (AUC). Significant changes in BAT parameters (%CD63+ and %CD203chigh) were found between the controls and patients. However, comparisons for %CD63+, %CD203chigh, AUC, and CD-Sens showed similar levels among patients with different symptoms. An optimal cut-off was established from ROC curves, showing a significant positive percentage of BAT in patients compared to controls and great values of sensitivity (>87.5%) and specificity (>85%). In addition, BAT showed differences in LTP-allergic patients tolerant to peanut using its corresponding LTP, Ara h 9. BAT can be used as a potential diagnostic tool for identifying LTP allergy and for differentiating peanut tolerance, although neither reactivity nor sensitivity can distinguish the severity of the clinical symptoms.
... Two patterns of peach allergy seem to be common among peach allergic patients, namely Pru p 3 and profilin-Bet v 1-related sensitization. In the first case (Pru p 3 sensitization), individuals may experience severe and systemic clinical symptoms, while patients with profilin-Bet v 1-related sensitization are prone to suffer from mild clinical symptoms (Gamboa et al. 2007). The most common symptoms of peach allergy correspond to OAS, although moderate (affecting skin, cardiovascular, and/or respiratory systems) to systemic life-threatening reactions (e.g. ...
This review provides a global overview on Rosaceae allergy and details the particularities of each fruit allergy induced by ten Rosaceae species: almond/peach/cherry/apricot/plum (Amygdaleae), apple/pear (Maleae), and raspberry/blackberry/strawberry (Rosoideae). Data on clinical symptoms, prevalence, diagnosis, and immunotherapies for the treatment of Rosaceae allergy are herein stated. Allergen molecular characterization, cross-reactivity/co-sensitization phenomena, the impact of food processing and digestibility, and the methods currently available for the Rosaceae detection/quantification in foods are also described. Rosaceae allergy has a major impact in context to pollen-food allergy syndrome (PFAS) and lipid transfer protein (LTP) allergies, being greatly influenced by geography, environment, and presence of cofactors. Peach, apple, and almond allergies are probably the ones most affecting the quality of life of the allergic-patients, although allergies to other Rosaceae fruits cannot be overlooked. From patients' perspective, self-allergy management and an efficient avoidance of multiple fruits are often difficult to achieve, which might raise the risk for cross-reactivity and co-sensitization phenomena and increase the severity of the induced allergic responses with time. At this point, the absence of effective allergy diagnosis (lack of specific molecular markers) and studies advancing potential immunotherapies are some gaps that certainly will prompt the progress on novel strategies to manage Rosaceae food allergies.
... Peach-induced contact urticaria seems particularly common in Spain and Italy [21][22][23] , probably due to the high amount of allergen contained in peach fuzz. 24 However, contact urticaria from other LTP sources including asparagus 25 , melon 26 and cannabis leaves 27,28 has also been reported. ...
Sensitization to lipid transfer protein (LTP), the most frequent cause of food allergy in southern Europe still shows several controversial, but also intriguing aspects. Some of these include the degree of cross‐reactivity between LTPs from botanically distant sources, the definition of risk factors, the role of some cofactors, clinical outcomes, geographical differences and the identification of the primary sensitizer in different areas. This review article tries to analyze and comment on these aspects point by point suggesting some explanatory hypotheses with the final scope to stimulate critical thoughts and elicit the scientific discussion about this issue in the readership.
... 5 Of these, the two main allergens Pru p 1 and Pru p 3 together account for more than 95% of peach allergies in Europe and China. 3,6,7 They induce two different allergy patterns: in central Europe and north China the symptoms are mild and local, such as oral allergy syndrome (OAS) related to Pru p 1, while in southern Europe and China the symptoms are mostly OAS and/or systemic due to Pru p 3. 3,8 Hypersensitivity caused by Pru p 1 is mostly induced by cross-reactions with Fagales pollen group 1 allergenic proteins, such as Bet v 1. [9][10][11] Three naturally occurring isoforms of Pru p 1, Pru p 1.0101, Pru p 1.0201, and Pru p 1.0301, have been identified in the "Earlygold" peach cultivar and their immunoglobulin E (IgE)-binding efficiency has been studied. Pru p 1.0301 is mainly expressed in peach pollen, and Pru p 1.0101 (DQ251187) and Pru p 1.0201 (KM350692) isoallergens are present in the fruit, with Pru p 1.0201 having the highest binding capacity to IgE compared with Pru p 1.0101 and Pru p 1.0301. ...
Background:
Pru p 1 is a major allergen in peach and nectarine, and the different content in varieties may affect the degree of allergic reactions. This study aimed to quantify Pru p 1 levels in representative peach varieties and select hypoallergenic Pru p 1 varieties.
Methods:
To obtain monoclonal and polyclonal antibodies, mice and rabbits, respectively, were immunized with recombinant Pru p 1.01 and Pru p 1.02. The Pru p 1 levels in fruits from 83 representative peach varieties was quantified by sandwich enzyme-linked immunosorbent assay (sELISA). nPru p 1 was obtained through specific monoclonal antibody affinity purification and confirmed by Western blot and mass spectrometry. The variable Pru p 1 content of selected varieties was evaluated by Western blot and the expression level of encoding Pru p 1 genes by quantitative polymerase chain reaction.
Results:
A sELISA method with monoclonal and polyclonal antibodies was built for quantifying Pru p 1 levels in peach. Pru p 1 was mainly concentrated in the peel (0.20-73.44 μg/g, fresh weight), being very low in the pulp (0.05-9.62 μg/g) and not detected in wild peach. For the 78 peach and nectarine varieties, Pru p 1 content varied widely from 0.12 to 6.45 μg/g in whole fruit. We verified that natural Pru p 1 is composed of 1.01 and 1.02 isoallergens, and the Pru p 1 expression level and Pru p 1 band intensity in the immunoblots were in agreement with protein quantity determined by ELISA for some tested varieties. In some cases, the reduced levels of Pru p 1 did not coincide with low Pru p 3 in the same variety in whole fruit, while some ancient wild peach and nectarines contained low levels of both allergens, and late-ripening yellow flesh varieties were usually highly allergenic.
Conclusion:
Pru p 1 content is generally low in peach compared to Pru p 3. Several hypoallergenic Pru p 1 and Pru p 3 varieties, "Zi Xue Tao," "Wu Yue Xian," and "May Fire," were identified, which could be useful in trials for peach allergy patients.
... Of note, in Spain, 91% (20/22) of cherry allergic patients were sensitized against LTP Pru av. 3, but only two patients were sensitized against other known cherry allergens, and 50% of patients reported systemic reactions after consumption of cherries [36]. Moreover, the reactivity to Pru p 3 correlated with severe reactions, whereas co-sensitization to profilin was associated with OAS [74]. This observation was confirmed by a study showing that patients with Pru p 3-specific IgE are less likely to develop severe symptoms when they are polysensitized by IgE reactivity to profilin Pru p 4 and Bet v 1like protein Pru p 1 [75]. ...
Purpose of Review
To provide an overview of the prevalence and clinical manifestation of non-specific lipid transfer proteins (LTP)-mediated allergies outside the Mediterranean area and to address potential reasons for the different geographical significance of LTP-driven allergies.
Recent Findings
LTPs are major allergens in the Mediterranean area, which frequently can elicit severe reactions. Pru p 3 the LTP from peach is reported as genuine allergen and is considered a prototypic marker for LTP-mediated allergies. However, both food and pollen LTP allergies exist outside the Mediterranean area, but with lower clinical significance, different immunogenicity, and less clarified role.
Summary
Evidence has been reported that in areas with high exposure to pollen, in particular to mugwort, pollen-derived LTPs can act as a primary sensitizer to trigger secondary food allergies. Co-sensitization to unrelated allergens might be causative for less severe reactions in response to LTPs. However, the reason for the geographical different sensitization patterns to LTPs remains unclear.
... Europe, it is connected mainly with systemic symptoms, in many cases due to sensitization to lipid-transfer protein Pru p 3 (Gamboa et al., 2007). Pru p 3 is a non-specific lipid transfer protein of peach fruit and is proposed to be a model of true food allergens (Salcedo et al., 2008), because of its resistance to proteolytic digestion, oral sensitisation and severe clinical symptoms (Salcedo et al., 2007). ...
Peach is a popular sweet fruit with a very good climate adaptation and high production. It offers many health benefits determined by its biochemical composition. However, sensitive people can be sensitised by Pru p 3 non-specific lipid transfer protein family directly or through cross reaction as a member of Bet v 1 homologues. The majority of research is focused on the protein, less data can be found in genomics or transcriptomics. This study performed RFLP analysis by chosen restricted enzymes (BfaI, MseI, NlaIII) for non-coding region of Pru p 3 (NCBI: KC311811.1) as a tool to distinguish closely related isoforms of the allergen. BfaI cut amplicon into 5 fragments corresponding to the Yulu variety in silico cleavage and polymorphism was not detected. For MseI and NlaIII polymorphisms were found in the cleavage sites, two types of restriction profiles were created for both. None of the NlaIII profiles corresponds to the restriction profile of in silico cleavage. The study confirms the varietal differences in Pru p 3 gene and supports a hypothesis that allergenicity depends on both qualitative and quantitative factors that are different and specific to each variety.
... The BAT is based on flow cytometry where the expression of activation markers is measured on the surface of allergen-stimulated basophils. BAT has been studied in the diagnosis of a variety of food allergies and its reported sensitivity ranges from 77% to 98%, and specificity from 75% to 100% [36][37][38][39][40][41]. ...
A food allergy is an immunoglobulin E (IgE)-mediated hypersensitive reaction to food, which consists in the appearance of allergic symptoms; it can vary from common urticaria to even fatal anaphylaxis. The prevalence of food allergies has been increasing in the past twenty years and it represents a major public health problem in industrialized countries. The mechanism that leads to food allergies is the lack of immunologic and clinical tolerance to food allergens. The diagnosis of IgE-mediated food allergies is based on the combined use of a detailed medical history, in-vivo, and in-vitro research of specific IgE, the elimination diet, and the double-blind placebo-controlled food challenge. The only currently available treatment for allergies is the strict elimination diet. This type of attitude, which we could define as “passive”, does not overcome the risk of accidental reactions due to involuntary intake of the culprit food. For food allergy management, an “active” approach is urgently needed, such as specific allergen immunotherapy, which is currently under development and only used for research purposes. This article aims to give an updated review of IgE-mediated food allergies in pediatric populations in terms of epidemiology, pathogenesis, prevention, diagnosis, and management.
... [7][8][9][10] Additionally, Pru p 3 behaves as the primary sensitizer in the development of food allergy to Rosaceae species in regions where the presence of birch is rare and the involvement of Bet v 1-like allergens is infrequent, such as in southern Europe. 3,[11][12][13] However, it has been described that Pru p 3 could lose its primary sensitizer role in regions where birch is scarce and the presence of other pollens is intense. 14,15 Olive tree pollinosis is worldwide increasing due to its extensive cultivar. ...
Background
Ole e 7 is a nonspecific lipid transfer protein (nsLTP) from olive pollen, one of the main allergenic pollens worldwide. This allergenic nsLTP is responsible for severe symptoms in regions with high olive pollen exposure, where many Ole e 7‐sensitized patients exhibit a co‐sensitization to the peach nsLTP, Pru p 3. However, there is no evidence of cross‐reactivity, which explains this observed co‐sensitization. Therefore, the purpose of this study was to explore the relationship between Ole e 7 and Pru p 3.
Methods
A total of 48 patients sensitized to Ole e 7 and/or Pru p 3 were included in the study. Specific IgE serum levels were measured by ImmunoCAP 250 and ELISA. Inhibition assays were performed to determine the existence of cross‐reactivity between both nsLTPs. Allergic response was analyzed ex vivo (basophil activation test) and in vitro (RBL‐2H3 mast cell model).
Results
Common IgG and IgE epitopes were identified between both allergens. IgE‐binding inhibition was detected in Ole e 7–monosensitized patients using rPru p 3 as inhibitor, reaching inhibition values of 25 and 100%. Ex vivo and in vitro assays revealed a response against rPru p 3 in four (31%) Ole e 7–monosensitized patients.
Conclusions
Our results suggest that Ole e 7 could play a new role as primary sensitizer in regions with high olive pollen exposure, leading to the peach nsLTP sensitization. This co‐sensitization process would occur because of the cross‐reactivity between Ole e 7 and Pru p 3 observed in some allergic patients.
... Studies in southern Europe showed that patients with peach allergy showing high sIgE-levels to Pru p 3 are more likely to show systemic reactions. 20,21 For peanut allergy, elevated sIgE to Ara h 1, 2 and 3 have been found to increase the risk for severe allergic reactions. 22,23 These findings permit a better risk assessment for patients suffering from peanut or peach allergy by their medical doctors. ...
Background:
Hymenoptera venom sensitization in highly exposed individuals frequently requires risk assessment for future severe sting reactions. In this study, we determined the prevalence of Hymenoptera venom sensitization in individuals who hunt and fish and analyzed possible correlations between the severity of sting reactions and the IgE sensitization profile.
Methods:
In this cross-sectional study, paper-based, self-filled questionnaires about previous insect stings and sting reactions were obtained from individuals who hunt and fish in Bavaria, Germany. Blood samples were taken and analyzed for the levels of tryptase, total IgE and IgE to honey bee (i1) and wasp (13) venom, the recombinant allergens rApi m 1, rApi m 2, rApi m 3, rApi m 5, rApi m 10, rVes v 1, rVes v 5, and the CCD marker molecule MUXF3. Odd ratios (ORs) for sensitization and anaphylaxis and Pearson's correlations for the different allergens were calculated.
Results:
Of 257 participants, 50.2% showed a sensitization to honey bee venom (i1), and 58.4% showed sensitization to wasp venom (i3). A total of 98.4% of participants claimed to have been stung at least once. Anaphylaxis was reported in 18.7%, and a local sting reaction was reported in 18.3%. The highest sensitization rates were found for whole venom extracts, sensitization to any of the available recombinant allergens exceeded sIgE levels to honeybee venom (i1) in 28.5% and to wasp venom (i3) in 52.9% of participants. Participants with a history of more than 5 stings showed a higher risk for anaphylaxis.
Conclusions:
Sensitization to Hymenoptera venom and their recombinant allergens are present in the majority of individuals who hunt and fish. Sensitization to distinct recombinant allergens does not necessarily affect the severity of sting reactions including anaphylaxis. A meticulous medical history of the number of previous stings as well as systemic reactions remains essential.
... 11,[67][68][69][70][71][72][73] The BAT with single allergen components can potentially improve its diagnostic accuracy, but further research studies are needed. 72,74,75 The BAT has been shown to be potentially useful in identifying the culprit allergen in cases of pollen-food allergy syndrome (PFAS), 71,76,77 allergy to red meat, 78 or food-dependent exercise-induced anaphylaxis. 79 As for other diagnostic tests, cutoffs determined for the BAT can vary with the patient population, the design of the study, and the methodology adopted for the BAT procedure and data analyses. ...
Various in vitro tests assess different aspects of the underlying immune mechanism of IgE-mediated food allergy. Some can be used for diagnostic purposes; specific IgE to allergen extracts is widely available; specific IgE to allergen components is used in most specialist centers, and the basophil activation test is becoming increasingly used clinically. IgE to allergen peptides, T-cell assays, allergen-specific/total IgE ratios, and allergen-specific IgG4/IgE ratios are currently reserved for research. Different factors can modulate the likelihood of IgE-mediated food allergy of a given allergy test result, namely, the patients' age, ethnicity, previous allergic reaction to the identified food, concomitant atopic conditions, and geographical location, and need to be taken into account when interpreting the allergy test results in the clinic. The importance of the specific food, the clinical resources available, and patient preferences are additional aspects that need to be considered when deciding whether an oral food challenge is required to reach an accurate diagnosis of IgE-mediated food allergy.
... Sensitization to LTPs is known to occur frequently in individuals living in the Mediterranean area, where it is often associated with severe, sometimes life-threatening reactions. [5][6][7][8] Peach LTP (Pru p 3) represents the molecule that dominates the immune response to LTPs in these countries and is regarded as a marker for severe systemic reactions to plant-derived food. 5 Awareness of LTP sensitization is also increasing in Northern and Central Europe. ...
In the Mediterranean area, lipid transfer proteins (LTPs) are important causes of plant food allergies often associated with severe allergic reactions. There, peach LTP (Pru p 3) seems to be the primary sensitizer, whereas in Central Europe little is known about the importance of LTP-sensitization. In this region allergen extract based diagnosis is often complicated by co-sensitization to Bet v 1, the major birch pollen allergen, its cross-reactive food allergens and profilins. We investigated the role of LTP-sensitization in Central European patients displaying strong allergic reactions to plant-derived food. Analysis of IgE-reactivity revealed that ten of thirteen patients were sensitized to Pru p 3, nine to Bet v 1and two to profilin. Our results showed that LTP-sensitization represents a risk factor for severe allergic symptoms in Central Europe. Furthermore, the strong IgE reactivity detected in immunoblots of plant food extracts indicated that Pru p 3 can be used as a marker allergen for LTP-sensitization also in Central European patients. This article is protected by copyright. All rights reserved.
... approximately one-third of the patients, and OAS in the other two-thirds [1,[5][6][7][8][9]. ...
Background:
The peach non-specific lipid transfer protein, Pru p 3, is the primary sensitizer in fruits and responsible for severe reactions in the Mediterranean area. Peach allergy is frequently associated with other allergies such as peanut. Therefore, it is important to assess how specific immunotherapy to Pru p 3 could affect both peach and peanut tolerance.
Objectives:
To evaluate peach and peanut desensitization and immunological changes after 1 year of Pru p 3 sublingual immunotherapy (SLIT) in patients with systemic allergic reactions to peach and/or peanut.
Methods:
Forty-eight peach allergic patients, 36 treated with SLIT and 12 non-treated, were monitored for 12 months. Treated patients were subclassified as peanut allergic (Group A), sensitized (Group B) or tolerant (Group C). SLIT effect was evaluated by skin prick test (SPT) reactivity and food challenge. Immunological changes were evaluated by monitoring sIgE and sIgG4 levels and basophil reactivity.
Results:
After 1 year of SLIT, the weal area in SPT significantly decreased and a significant increase in peach threshold in treated patients was observed (P < 0.001). Patients in Group A showed a significant decrease in peanut SPT weal area and an increase in peanut threshold (P < 0.001). Immunological changes were observed in treated patients only, with a significant decrease in sIgE and a parallel increase in sIgG4, sIgG4/sIgE and basophil reactivity for both Pru p 3 and Ara h 9.
Conclusions and clinical relevance:
After 1 year, Pru p 3 SLIT induces both desensitization and immunological changes not only for peach but also for other food allergens relevant in the induction of severe reactions such as peanut.
... 500 mm 3 /year), and the region's pollen load is marked by a significant presence of grass pollen, but also by elevated concentrations from olive trees and species of the Parietaria genus, with a light-to-moderate presence of mugwort and plane tree pollen. In Spain, LTP sensitization is reported to be the most prevalent sensitization among peach-allergic patients of the study region [21] . Likewise, and despite the climatic differences between the northern and central/southern regions of the country, a similar LTP sensitization is observed in Italian patients suffering from anaphylaxis [6] . ...
Background:
Plant food allergies associated with lipid transfer protein (LTP) have been widely described in the Mediterranean Basin.
Objective:
The aim of this work was to describe the clinical profile and pollen sensitization of plant food- allergic patients sensitized to LTP in a non-Mediterranean area.
Methods:
Patients with clear IgE-mediated symptoms associated with plant foods and a positive skin prick test (SPT) to Pru p 3 were included in a prospective study in the north of Spain. Reported symptoms were analyzed together with a battery of food and pollen SPTs and specific IgE components by ISAC microarray. Cross-inhibition studies were performed by ImmunoCAP with plane tree, mugwort and rPru p 3.
Results:
Among the 72 patients included, the most frequent food allergy reported was to peaches (69%) followed by nuts (walnuts 55%, peanuts 54% and hazelnuts 43%). Most patients suffered from symptoms with multiple plant foods (a median of 6 foods per patient). Regarding the patients' pollen sensitization, 36% were sensitized to mugwort pollen (72% showing sIgE to Art v 3), 33% to grass pollen and 24% to plane tree pollen (94% with sIgE to Pla a 3). Inhibition studies showed that specific IgEs against mugwort and plane tree pollen are inhibited by Pru p 3 in a strong manner, whereas Pru p 3 was less inhibited by pollen extracts.
Conclusions:
LTP syndrome occurs in a non-Mediterranean area and is related to multiple sensitizations to foods and pollens such as plane tree and mugwort. In these pollen sensitizations, Pru p 3 seems to be the primary sensitizer.
... The use of component-resolved diagnosis (CRD) has improved the diagnosis of food allergies, as different allergenic profiles have been reported to be related to particular types of clinical reactivity [3][4][5]. Furthermore, differences in allergenic profiles have been described for different geographical regions [6,7]. Lipid transfer proteins (LTPs) are the main allergens in tree nut allergy in the Mediterranean area [6,8,9], although it has been suggested that LTPs might also be markers of peach sensitization in the absence of clinical allergy [8,10]. ...
Background: Component-based diagnosis on multiplex platforms is widely used in food allergy but its clinical performance has not been evaluated in nut allergy. Objective: To assess the diagnostic performance of a commercial protein microarray in the determination of specific IgE (sIgE) in peanut, hazelnut, and walnut allergy. Methods: sIgE was measured in 36 peanut-allergic, 36 hazelnut-allergic, and 44 walnut-allergic patients by ISAC 112, and subsequently, sIgE against available components was determined by ImmunoCAP in patients with negative ISAC results. ImmunoCAP was also used to measure sIgE to Ara h 9, Cor a 8, and Jug r 3 in a subgroup of lipid transfer protein (LTP)-sensitized nut-allergic patients (positive skin prick test to LTP-enriched extract). sIgE levels by ImmunoCAP were compared with ISAC ranges. Results: Most peanut-, hazelnut-, and walnut-allergic patients were sensitized to the corresponding nut LTP (Ara h 9, 66.7%; Cor a 8, 80.5%; Jug r 3, 84% respectively). However, ISAC did not detect sIgE in 33.3% of peanut-allergic patients, 13.9% of hazelnut-allergic patients, or 13.6% of walnut-allergic patients. sIgE determination by ImmunoCAP detected sensitization to Ara h 9, Cor a 8, and Jug r 3 in, respectively, 61.5% of peanut-allergic patients, 60% of hazelnut-allergic patients, and 88.3% of walnut-allergic patients with negative ISAC results. In the subgroup of peach LTP-sensitized patients, Ara h 9 sIgE was detected in more cases by ImmunoCAP than by ISAC (94.4% vs 72.2%, P<.05). Similar rates of Cor a 8 and Jug r 3 sensitization were detected by both techniques. Conclusions: The diagnostic performance of ISAC was adequate for hazelnut and walnut allergy but not for peanut allergy. sIgE sensitivity against Ara h 9 in ISAC needs to be improved.
... We validated the diagnostic cut-offs in a prospectively and independently recruited population and the diagnostic performance of BAT was still very good in this second study population. Over the past few years, other studies have assessed the performance of BAT in the diagnosis of allergy to different foods, including peanut [12,[15][16][17][18], cow's milk [19,20], egg [17,19], wheat [21][22][23][24][25], hazelnut [26][27][28], shellfish [29] and peach [30][31][32], as well as in the diagnosis of pollen-food syndromes [33][34][35] -Table 1. ...
Oral food challenge (OFC) is the gold-standard to diagnose food allergy; however, it is a labour and resource-intensive procedure with the risk of causing an acute allergic reaction, which is potentially severe. Therefore, OFC are reserved for cases where the clinical history and the results of skin prick test and/or specific IgE do not confirm or exclude the diagnosis of food allergy. This is a significant proportion of patients seen in Allergy clinics and results in a high demand for OFC. The basophil activation test (BAT) has emerged as a new diagnostic test for food allergy. With high diagnostic accuracy, it can be particularly helpful in the cases where skin prick test and specific IgE are equivocal and may allow reducing the need for OFC. BAT has high specificity, which confers a high degree of certainty in confirming the diagnosis of food allergy and allows deferring the performance of OFC in patients with a positive BAT. The diagnostic utility of BAT is allergen-specific and needs to be validated for different allergens and in specific patient populations. Standardisation of the laboratory methodology and of the data analyses would help to enable a wider clinical application of BAT.
... The risk-benefit of OIT should be carefully considered in individuals with no life-threatening food allergies. [27][28][29][30] Therefore, these allergic individuals with such symptoms should be considered cautiously regarding the risk-benefit ratio. ...
Chronic eosinophilic pneumonia (CEP) is a rare lung disease and is especially uncommon in children. It presents with subacute respiratory symptoms of hypoxemia and dyspnea, peripheral infiltrates on imaging, and eosinophilia. However, it can be difficult to diagnose, as there is no strict diagnosis criteria and the clinical findings may be very nonspecific. In this case report, we describe a 14-year-old female with an unusual presentation of asymptomatic bronchiectasis, and the role of surgical lung biopsy in the diagnosis of CEP when no peripheral or alveolar eosinophilia is seen. It suggests that perhaps bronchiectasis can also be an unusual presenting sign of CEP and that there may be more asymptomatic cases of CEP with the true incidence being underreported, especially in the pediatric population.
... Part of this difficulty in determining the threshold levels for an allergen stems from "the lack of uniformity for criteria for making diagnosis" (Schneider Chafen et al., 2010). Variable sensitivity to different allergenic proteins from the same food source (Gamboa et al., 2007) may further complicate the threshold determination (Crevel et al., 2008). The mAb 4C10-based assay is sensitive in detecting 0.15e10 mg/g whole almond flour in a food matrix under the assay conditions. ...
Amandin presence in 108 almond genotypes/hybrids and 80 almond marketing varieties grown in different locations was determined using murine monoclonal antibody 4C10-based sandwich ELISA. The results indicated that amandin was present in all the tested samples. The ELISA immunoreactivity variations were up to 8 fold among genotypes/hybrids and 2.5 fold among the almond marketing varieties. Amandin content variations were also confirmed using Western blot and dot blot. No correlation was observed between almond seed size and total soluble protein or amandin content.
... 3,61 Olive and Salsola pollen are largely responsible for cross-sensitizations with foods in Mediterranean regions. 3,61,120 In northern China, exposure to mugwort LTP Art v 3 has been implicated in causing peach allergy, 121 whereas in southern Europe, peach allergy is attributed to primary sensitization to peach LTP Pru p 3. 122 Geography greatly contributes to the diagnostic complexity of pollen-food syndrome. ...
Oral allergy syndrome (OAS) or pollen-food allergy syndrome (PFS) is a hypersensitivity reaction to plant-based foods, manifesting most commonly with pruritus of the lips, tongue, and mouth. Unlike simple food allergy, OAS requires prior sensitization to a cross-reacting inhalant allergen rather than direct sensitization to a specific food protein. In this review, we summarize the clinical features and pathophysiology of OAS and provide an overview of known pollen-food associations.
Background
Immunoglobulin E (IgE) blood tests are used to detect sensitizations and potential allergies. Recent studies suggest that specific IgE sensitization patterns due to molecular interactions affect an individual's risk of developing allergic symptoms.
Objective
The aim of this study was to reveal specific IgE sensitization patterns and investigate their clinical implications in Hymenoptera venom allergy.
Methods
In this cross-sectional study, 257 hunters or fishers with self-filled surveys on previous Hymenoptera stings were analyzed. Blood samples were taken to determine Hymenoptera IgE sensitization levels. Using dimensionality reduction and clustering, specific IgE for 10 Hymenoptera venom allergens were evaluated for clinical relevance.
Results
Three clusters were unmasked using novel dimensionality reduction and clustering methods solely based on specific IgE levels to Hymenoptera venom allergens. These clusters show different characteristics regarding previous systemic reactions to Hymenoptera stings.
Conclusion
Our study was able to unmask non-linear sensitization patterns for specific IgE tests in Hymenoptera venom allergy. We were able to derive risk clusters for anaphylactic reactions following hymenoptera stings and pinpoint relevant allergens (rApi m 10, rVes v 1, whole bee, and wasp venom) for clustering.
The field of food allergy has seen tremendous change over the past 5-10 years with seminal studies redefining our approach to prevention and management and novel testing modalities in the horizon. Early introduction of allergenic foods is now recommended, challenging the previous paradigm of restrictive avoidance. The management of food allergy has shifted from a passive avoidance approach to active interventions that aim to provide protection from accidental exposures, decrease allergic reaction severity and improve the quality of life of food-allergic patients and their families. Additionally, novel diagnostic tools are making their way into clinical practice with the goal to reduce the need for food challenges and assist physicians in the - often complex - diagnostic process. With all the new developments and available choices for diagnosis, prevention and therapy, shared decision-making has become a key part of the medical consultation, enabling patients to make the right choice for them, based on their values and preferences. Communication with patients has also become more complex over time, as patients are seeking advice online and through social media, but the information found online may be outdated, incorrect, or lacking in context. The role of the allergist has evolved to embrace all the above exciting developments and provide patients with the optimal care that fits their needs. In this review, we discuss recent developments, as well as the evolution of the field of food allergy in the next decade.
Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE‐mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE‐mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well‐defined, highly pure molecules for component‐resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the “EAACI Molecular Allergology User's Guide” (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state‐of‐the‐art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.
The global food market needs to grow and supply food demand to feed the growing world population. Alternative food proteins, including novel sources of safe foods and ingredients, are the candidates that could provide more environmentally sustainable choices, animal welfare, and consumers health. Novel foods and food proteins must undergo premarket safety evaluations including allergenicity assessment to reduce the risk of cross-reactivity with known allergens and uncharacterized risk to food allergic individuals. This research addressed the safety assessment of some novel foods and food ingredients using the study of stability of proteins in pepsin and sequence identity analysis in the AllergenOnline database. Subject samples included microalgae, hemp heart protein, sweet protein, and manganese related peroxidase. In addition, food allergy is a complicated and multifactorial disease. Safety evaluation based on the IgE binding, as a part of risk assessments required by CODEX for the protein sequence identity matches of >35%, usually overestimates the true cross-reactivity due to the false positive results. The results of this study revealed that in vitro protein stability in pepsin in conjunction with other safety assessments can suggest a positive predictive value for a putative food allergen. The proposed approach described in this thesis included a combination of assays of protein stability in pepsin and meaningful sequence identity matches. Serum IgE binding evaluations would be useful when the match criteria are >50% sequence identity in a full sequence. For the biological relevance of these assessments, serum inhibition western blot analysis and basophil activation test (BAT) using humanized rat basophilic (hRBL) cell line can improve the accuracy of food safety assessment for the risk of novel food proteins. The combination of all methods used in this study would help to propose a better approach for food security and premarket evaluations of novel food proteins. Advisor: Richard E. Goodman
Food allergy diagnosis has a massive impact on the lives of patients and their families. Despite recent developments with specific IgE to component allergens, a significant proportion of patients assessed for possible food allergy require oral food challenge (OFC) to ensure an accurate diagnosis. More precise diagnostic methods are required to reduce the need for OFCs. Bead-based epitope assays and cellular tests, such as basophil activation and mast cell tests (BAT and MAT, respectively), are the most novel and promising tests on the horizon. There is a pathway to pursue in order to enable their incorporation in clinical practice, including standardization, technical validation, clinical validation, external validation, overcoming practical and logistical issues, and regulatory approval. Valuable clinical application of these tests goes beyond diagnosis and includes risk assessment to identify the allergic patients who are most sensitive and at risk of severe allergic reactions and also to define prognosis and assess clinical response to immunomodulatory treatments.
This article discusses contact urticaria syndrome definition, history, epidemiology, occupational relevance, mechanisms, clinical manifestations, diagnostic tools, agents responsible, and how to prevent and treat the patients affected. Contact urticaria syndrome is often misdiagnosed because it is not well known or recognized by physicians. Commonly the patient recognizes the cause of the clinical symptom, but the cause can be exceptional or new. Triggers include proteins, chemical compounds, agricultural chemicals, metals, plants, foods, and other substances. The objective of this article is to help dermatologists, toxicologists, and immunologists by providing diagnostic tools to avoid the culprit agent and treat the patients.
Allergien sind immunologisch vermittelte Überempfindlichkeitsreaktionen gegen eigentlich harmlose Fremdsubstanzen aus der Umwelt (Allergene). Chronische allergische Erkrankungen führen zu erheblichen Einschränkungen der Lebensqualität und zu hohen, direkten und indirekten, sozioökonomischen Kosten. Mit ca. 30 Millionen betroffenen Menschen allein in Deutschland kann die Allergie mit Recht als Volkskrankheit bezeichnet werden. Die pathologischen Symptome einer Allergie manifestieren sich vor allem an Organen oder Geweben an den Grenzflächen des Organismus mit seiner Umgebung wie z.B. Haut, Atemwege oder den Gastrointestinaltrakt.
Die häufigste Allergieform ist die Soforttyp- oder Typ I-Allergie mit den klinischen Manifestationen allergische Rhinokonjunktivitis (Heuschnupfen), allergisches Asthma bronchiale, atopische Dermatitis und Nahrungsmittelallergie. Ein zentrales Ereignis der Immunpathogenese aller Formen der Typ I-Allergie ist die exzessive Produktion allergenspezifischer IgE-Antikörper (Sensibilisierung). Der labordiagnostische Nachweis dieser IgE-Antikörper dient der Identifikation des allergieauslösenden Allergens, um dort, wo möglich durch Allergenkarenz oder mittels Durchführung einer (allergen)spezifischen Immuntherapie (SIT) die allergische Reaktionsbereitschaft des Organismus zu minimieren.
Die klassische IgE-Diagnostik mit Gesamtextrakten der in Frage kommenden Allergenquellen stößt allerdings bei einer Reihe wichtiger Fragestellungen an ihre Grenzen, da die Extrakte Mischung vieler verschiedener Proteinkomponenten mit jeweils unterschiedlicher Potenz zur Sensibilisierung bzw. Auslösung einer allergischen Reaktion darstellen. Die molekulare oder Komponenten-basierte IgE-Diagnostik hingegen verwendet zum Nachweis der IgE-Reaktivität rekombinant hergestellte Einzelallergene, die jedes für sich präzise hinsichtlich ihrer physikalischen, chemischen und immunologischen Eigenschaften definiert sind. Diese Methodik kann daher deutlich mehr leisten als das herkömmliche Testverfahren zum Nachweis des spezifischen IgE mit Allergenextrakten: sie erlaubt eine Differenzierung von IgE-Reaktionen gegen für diese Allergenquelle spezifische Komponenten, die eine primäre (genuine) Sensibilisierung nahelegen, und IgE-Reaktionen gegen Proteine, die strukturelle Ähnlichkeiten zu Proteinen anderer Allergenherkunft aufweisen und somit infolge dieser sekundären Sensibilisierung eine Kreuzreaktion auslösen. Diese Unterscheidung ermöglicht eine fundierte Risikoeinschätzung der klinischen Relevanz und der Schwere einer möglichen allergischen Reaktion. Darüber hinaus hilft die Komponenten-basierte IgE-Diagnostik dem Therapeuten im Rahmen der SIT bei der Erkennung von Mono- und Polysensibilisierungen sowie der gezielten Auswahl der Allergenkomponenten, die den maximalen Behandlungserfolg versprechen.
Background:
Lipid transfer protein (LTP) is a major fruit allergen. It has, however, recently been revealed that the systemic reaction in peach-allergic patients is related not only to LTP (Pru p 3) but also to gibberellin-regulated protein (Pru p 7). We investigated recombinant Pru p 7 (rPru p 7) for its potential use in worldwide standardization for the diagnosis of peach allergy.
Methods:
Natural Pru p 7 (nPru p 7) was purified from peach crude extract using a monoclonal antibody affinity column. Complementary DNA for Pru p 7 was cloned and expressed in Escherichia coli and Pichia pastoris. Serum immunoglobulin (Ig) E in peach-allergic patients was examined by enzyme-linked immunosorbent assay (ELISA) using nPru p 7 and rPru p 7 (E. coli product: erPru p 7 and P. pastoris product: prPru p 7).
Results:
Peach-allergic patients (n=27) were diagnosed and categorized into oral reaction (n=10) or systemic reaction (n=17). The nPru p 7 positivity based on serum IgE levels was 52% in the systemic-reaction group and 0% in the oral-reaction group (P<0.05). In the systemic-reaction group, there was no significant difference in reactivity between nPru p 7 and prPru p 7, but the reactivity of erPru p 7 was significantly lower than those of nPru p 7 and prPru p 7 (P<0.05).
Conclusions:
We found that prPru p 7 exhibited reactivity in ELISA comparable to that of nPru p 7 for the diagnosis of peach allergy with systemic reaction.
Cette thèse actualise les connaissances de l'évaluation de l'allergénicité des aliments et son application au diagnostic de l'allergie alimentaire. Après la définition, les caractéristiques et la classification des allergènes alimentaires, les phénomènes physico-chimiques modifiant l'allergénicité des aliments ainsi que les réactivités croisées sont décrites. Ainsi sont introduits les outils cliniques et biologiques utiles au diagnostic de l'allergie alimentaire et à la détection des traces d'allergènes alimentaires. Une collaboration étroite entre cliniciens et chercheurs biologistes, permet d'optimiser la prise en charge diagnostique et thérapeutique de l'allergie alimentaire. Cette démarche se concrétise par la mise à disposition et l'utilisation de divers outils (développement d'allergènes recombinants, dosage de contaminants alimentaires dans des médicaments ou aliments, ...) et est illustrée par diverses mises en situation clinique réelles.
Freshly consumed peaches (Prunus persica L. Batsch) can cause allergic reactions in the worldwide population because of the presence of four classes of allergens (Pru p 1, Pru p 2, Pru p 3, and Pru p 4). Fruit bagging has been widely practiced in peach cultivation to improve fruit quality; however, its effect on the expression of peach allergen-encoding genes remains unknown. In this study, the influence of fruit bagging with opaque paper bags on the major peach allergen-encoding genes, including Pru p 1.01, Pru p 1.06B, Pru p 2.01B, Pru p 2.02, Pru p 3.01, Pru p 4.01, and Pru p 4.02, were measured by means of real-time PCR. A significant reduction in transcript accumulation was observed for all of the selected genes in the epicarp of the bagged peach fruits, while a slight increase was observed in the mesocarp for these genes, with the two exceptions of Pru p 2.02 and Pru p 3.01. For most of these genes, much higher transcripts were determined in the epicarp than in the mesocarp. Taken together, a significant reduction in the transcription rate of the allergen-encoding genes in the whole peach fruit was achieved by shading with opaque paper bags. According to these data, modifications in growing practices of peach may help to obtain fruits with lower levels of allergens, and thus contribute to reducing potential allergenic risks in consumers.
Introdução:Na região do Mediterrâneo, os frutos frescos (especialmente as rosáceas) e os
frutos secos são os alimentos mais frequentemente envolvidos em reações alérgicas
alimentares. A alergia a estes frutos é causada sobretudo por sensibilização a proteínas
transportadoras de lípidos (lipid transfer proteins-LTP) que parecem ser as mais relevantes do
ponto de vista clínico.
Objetivo:Caracterizar o perfil alergológico dos doentes portugueses com síndrome-LTP
residentes no Barlavento Algarvio, comparar as características destes doentes com as de
outras populações estudadas com a mesma patologia e avaliar o impacto na qualidade de vida
devido à alergia alimentar nas crianças incluídas na amostra.
Métodos:Foram estudados 14 doentes com síndrome-LTP confirmado. Foi colhida uma
história clínica, realizados testes cutâneos por picada e através de técnica prick-to-prick para
uma bateria alargada de alimentos e em crianças até aos 12 anos aplicado um Questionário de
Qualidade de Vida (FAQLQ-PF).
Resultados:Os alimentos que mais frequentemente causavam alergia foram a casca de
pêssego (90%), polpa de pêssego (63,6%), amendoim (58,3%), néctar de pêssego (55,6%) e noz
(41,7%) e os sintomas mais frequentemente reportados foram SAO (50%), urticária (50%),
anafilaxia (35,7%) urticária com angioedema (14,3%), angioedema da via aérea superior, rinite
ou asma, sintomas gastrointestinais (7,1% cada). Do ponto de vista de sensibilização, os
alimentos mais frequentemente identificados foram a casca de pêssego (92,9%), néctar de
pêssego (85,7%), polpa de pêssego e noz (71,4%), girassol e amora (63,6%).
Conclusão:Os doentes portugueses estudados apresentam um conjunto de características
distintas, destacando-se a presença de alergia alimentar frequente a pêssego, amendoim e
noz, a presença maioritariamente de sintomas sistémicos. As sensibilizações foram
identificadas principalmente a pêssego, néctar de pêssego, noz, girassol e amora. A amostra
não apresentava sensibilização frequente a pólenes e não foram identificados co-fatores
relevantes. A alergia alimentar tem um impacto negativo na qualidade de vida das crianças até
12 anos estudadas.
IgE-mediated Cannabis (C. sativa, marihuana) allergy seems to be on the rise. Both active and passive exposure to cannabis allergens may trigger a C. sativa sensitization and/or allergy. The clinical presentation of a C. sativa allergy varies from mild to life-threatening reactions and often seems to depend on the route of exposure. In addition, sensitization to cannabis allergens can result in various cross-allergies, mostly for plant foods. This clinical entity, designated as the "cannabis-fruit/vegetable syndrome" might also imply cross-reactivity with tobacco, natural latex and plant-food derived alcoholic beverages. Hitherto, these cross-allergies are predominantly reported in Europe and appear mainly to rely upon cross-reactivity between non-specific lipid transfer proteins (ns-LTPs) or thaumatin-like proteins (TLPs) present in C. sativa and their homologues, ubiquitously distributed throughout plant kingdom. At present, diagnosis of cannabis-related allergies predominantly rests upon a thorough history completed with skin testing using native extracts from crushed buds and leaves. However, quantification of specific IgE (sIgE) antibodies and basophil activation tests (BAT) can also be helpful to establish correct diagnosis. In the absence of a cure, treatment comprises absolute avoidance measures. Whether avoidance of further use will halt the extension of related cross-allergies remains uncertain. This article is protected by copyright. All rights reserved.
The aim of this work is to study the effect of High Pressure processing (HPP) on the allergenicity of the main protein involved in peach allergy (Pru p 3). Results obtained showed that most pressure/time combinations slightly enhanced in vitro IgE-binding to Pru p 3 and peach extract. Moreover, additional tests were carried out by means of skin prick tests on peach allergic patients. Different from in vitro results, in vivo effects evidenced that HPP (600MPa/5min) can either reduce or increase Pru p 3 allergenicity, depending on the particular sensitisation of each patient. Notwithstanding this variability, it is highly remarkable that the skin response to pressurised peach extract was stronger in more than half of individuals. These results would suggest a higher risk of HPP-treated peach products to elicit an allergenic reaction. However, it has been also proved that matrix plays an important role in peach allergenicity modification. Consequently, further investigations are needed before extrapolating results to more complex products.
The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.
Opinion statement
IgE-mediated food allergy constitutes an important and increasing health issue with significant impairment of quality of life and significant morbidity and mortality. It affects children, as well as adolescents, and adults. Correct diagnosis of food allergy relies upon history supplemented by quantification of specific IgE (sIgE) antibodies and/or skin tests. Unfortunately, as these tests do not demonstrate absolute predictive values, controlled oral provocation tests might be needed to confirm/exclude diagnosis. However, it is unlikely oral challenges to enter mainstream application, mainly because of obvious ethical reasons. Therefore, correct diagnosis of food allergy might benefit from novel in vitro diagnostics such as allergen component-based sIgE assays and flow cytometric quantification of in vitro activated basophils. As a matter of fact, these tests might prove to be particularly helpful in discriminating genuine allergy from merely sensitization. Furthermore, they might be useful in establishing individual risk profiles, predicting persistence of allergy, and facilitating therapeutic approach. This review focuses on the applications and limitations of the basophil activation test in IgE-mediated food allergy. Anno 2016 we believe that the utility and usefulness of basophil-activation experiments need to be reevaluated thoroughly, in view of difficulties inherent to the correct preparation and storage of allergen extracts, optimizing and standardizing stimulation conditions, and also the potential of alternative diagnostics such as component resolved diagnosis that are becoming more readily accessible.
The program of the European Congress of Allergology EAACI 2007 (Goteborg 9-13 June) covered many current problems dealing with general allergy as well as those in different specialized sectors of our discipline. Among the questions considered were the role of virus infection in the course of asthma, the production of IgE and phylogenesis, the predictive value of the production of IgE in the newborn and older children, T lymphocytes, anaphylaxis, profilins, and non-invasive markers of allergic inflammation. The importance of these the topics continues to be explored. The answers might explain the similarity between asthma in humans and in cats, the relation between hyper-IgE and exacerbations of asthma (where the risk is multiplied by two with rhinovirus infections), the importance of certain food allergens causing anaphylaxis (shelled nuts, especially peanuts, and exotic nuts), the importance of measuring exhaled NO in asthmatics, etc, (c) 2007 Elsevier Masson SAS. Tous droits reserves.
Food allergies continue to increase exponentially and therapies that can modify the natural course of disease is a recent top priority of the research. IgE-mediated food allergy represents both a promising and an intriguing disease of application for allergen specific immunotherapy. In particular, oral immunotherapy (OIT) may offer a novel effective therapeutic modality for persistent and severe forms of food allergies. In such patients, avoidance of the causative foods only may be insufficient because of the risk of unplanned exposure to causative foods. In patients with cow's milk, hen's egg, and peanut allergies, several recently published studies, including meta-analysis, confirmed the overall benefit of OIT. However, the definitive evidence of efficacy and safety with long-term therapeutic or disease-modifying effects is limited. In current protocols, entry indications, and initial-escalating-maintenance doses, the form of antigens, durations, and follow-up periods await to be standardized. Most of the clinical trials of OIT demonstrate effective desensitization, but the ability for inducing long-term tolerance remains to be improved, and the ratio of risks versus benefits of OIT should be considered in detail. The ultimate goal is extending OIT to primary care practice, but at this time, OIT remains within the purview of allergy specialists in terms of associated risk-benefit ratios, related safety, and long-term tolerance induction.
Results of immunological and molecular biology investigations over last decades allowed clear to specify mechanisms of development and clinical features of allergic reactions to food of plant origin, including allergies to fruits Prunus persica - peaches and nectarines. The article contains the analysis of literature data on allergic reactions to peach, as well as clinical observations of the patients with this kind of allergy and of the results of the component component resolved diagnosis, ISAC ImmunoCAP, conducted by these patients. The collected data allow to detect two fundamentally different types of allergic reactions to Prunus persica. This is due to sensitization to allergen Pru p 3 severe systemic reaction, and due to sensitization to Pru p 1 or Pru p 4 – local response, manifesting oral allergy syndrome and associated with sensitization to pollen allergens.
Lipid transfer proteins (LTPs) are major allergens of Rosaceae fruits in the Mediterranean area. IgE-cross-reactivity has been demonstrated in vitro among LTPs from peach, apple, chestnut and Artemisia pollen. The aim of this study was to evaluate the reactivity to LTPs from peach, apple, chestnut and Artemisia pollen by means of skin prick tests (SPTs).
Forty-seven patients allergic to peach (peach group), 20 patients sensitized to Artemisia pollen with no food allergies (Artemisia group), and 12 control subjects were skin tested with fresh peach, as well as with whole extracts and purified LTPs of peach, apple, chestnut and Artemisia pollen.
The rates of positive SPTs for peach, apple, chestnut and Artemisia LTPs were, respectively, 91, 77, 23, and 36% in the peach group, and 30, 5, 15 and 40% in the Artemisia group. No response was observed in the control subjects. SPTs with peach LTP strongly correlated with SPTs conducted with fresh peach. In the peach group, the most frequent pattern of reactivity to LTPs was the combination peach-apple (45%), followed by peach-apple-Artemisia-chestnut (21%). Significant correlations were found between peach and apple LTPs, and between Artemisia and chestnut LTPs. Positive SPTs to chestnut LTP were only observed in patients with positive SPTs to Artemisia LTP. All the patients with positive case histories to chestnut reacted to chestnut LTP.
LTPs are plant panallergens with different patterns of cross-reactivity. They are major allergens of Rosaceae fruits and seem to be involved in allergic reactions to unrelated foodstuffs such as chestnut, probably through sensitization to the cross-reactive Artemisia LTP. Rosaceae LTPs could be useful tools for in vivo diagnosis of Rosaceae fruit allergy.
In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, and the test reliability is affected by false-negative reactions.
We sought to evaluate a panel of recombinant allergens (RAs) derived from one allergenic food for use in component-resolved in vivo diagnosis, taking cherry as a model food.
Seventy-nine subjects were included in the study: 24 Swiss patients (group 1) with a positive double-blind placebo-controlled food challenge result to cherries, 23 patients with birch pollen allergy but without cherry allergy (group 2), 23 nonatopic subjects (group 3), and 9 Spanish patients with a history of a cherry allergy (group 4). SPTs were performed in duplicate by using recombinant cherry allergens (Bet v 1-related allergen: recombinant (r) Pru av 1; profilin: rPru av 4; and lipid transfer protein: rPru av 3) in concentrations of 10, 50, and 100 microg/mL. Furthermore, IgE reactivity to rPru av 1, rPru av 4, and rPru av 3 was assessed by means of immunoblot analysis.
SPT responses with rPru av 1, rPru av 4, and rPru av 3 were positive in 92%, 17%, and 4% of the patients in group 1; in 74%, 30%, and 0% of the patients in group 2; in 0%, 22%, and 89% of the patients in group 4; and negative for all nonatopic subjects (group 3). Thus the sensitivity of a positive SPT response to at least one of the 3 RAs was 96%. The specificities, negative predictive values, and positive predictive values with the 3 RAs were 100%, 96%, and 100% if calculated in relation to the nonatopic control group but 17%, 79%, and 60% when calculated in relation to the control group with birch pollen allergy. The correlation between SPT and immunoblotting results was excellent. Sensitization to rPru av 3 was associated with more severe symptoms than sensitization to rPru av 1.
SPTs with RAs proved to be highly sensitive for diagnosis of cherry allergy. Component-resolved in vivo diagnosis with standardized amounts of stable RAs allows us to determine sensitization patterns directly, to correlate them with severity of clinical symptoms, and to analyze geographic differences.
The aim of this study was to try to clarify which are the pollens that more probably cause pollinosis amongst the Madrid population. Methods: We performed pollen counts with a Burkard sampler (1979-96) and the results were compared with the skin tests results obtained in a group of 411 pollinosis patients resident in Madrid. The pollen counts also were compared with the monthly and annual antihistaminic sales. Results: The most common airborne allergenic pollens were Platanus sp (17%), grasses (13%), Cupressaceae (12% of total pollen), Olea sp (8%) and Plantago spp (3%). The prevalence of positive skin prick tests was: grasses (94%), Olea europaea (61%), Plantago lagopus (53%) Platanus hispanica (52%) and Cupressus arizonica (20%). We observed a correlation between the annual antihistaminic sales (1991-96) and the total annual pollen counts of grasses and Plantago (p<0.05) and also a correlation between the monthly antihistaminic sales (May-July of 1994-96) and the monthly pollen counts of grasses, Plantago and Olea (p<0.05). Conclusion: Grasses are the most important cause of pollinosis in Madrid and are also responsible for the important inter annual variation of the antihistaminic sales in Madrid.
Sensitization to peach and related Rosaceae fruits without clinical expression is commonly observed as the result of the extensive cross-reactivity of IgE antibodies directed toward lipid transfer proteins (LTPs), Bet v 1 homologues, profilins, and carbohydrate determinants.Objective
We aimed to study whether there are any clinical or immunologic differences between patients allergic to peach and those who have a current clinically irrelevant sensitization to this fruit.Methods
One hundred subjects with adverse reactions to peach were evaluated by medical history, skin prick tests with fresh peach and purified peach LTP (Pru p 3), and specific IgE determinations to peach, rBet v 1, and rBet v 2 (birch profilin). Clinical reactivity to peach was established by double-blind, placebo-controlled food challenges. The clinical characteristics and the in vivo and in vitro tests were compared between allergic and nonallergic patients.ResultsPeach allergy was confirmed in 76 patients and ruled out in 16; 2 patients dropped out, and the study was not conclusive in 6 individuals (placebo reactors). Pollen allergy was found in 76% of the allergic patients and in 100% of the nonallergic patients. Positive responses to Pru p 3, rBet v 1, and rBet v 2 were observed in 62%, 7%, and 34% of patients allergic to peach, respectively. The sensitization rate to Pru p 3 was significantly higher among subjects allergic than nonallergic to peach (62% vs 31%, P = .02). IgE responses to rBet v 2 were more frequent among subjects allergic to pollen, but no difference was observed in the presence or absence of peach allergy.Conclusions
Pru p 3 is the major allergen of peach in our population, and the IgE response to this allergen is related to the clinical expression of peach allergy. Sensitization to profilin is observed in those patients with an associated pollen allergy but does not appear to be related to the clinical reactivity to peach.
In this study serum samples collected from 20 patients with birch pollen allergy were investigated. All patients had experienced allergic symptoms after contact with or ingestion of particular fresh fruits and vegetables known as birch pollen-related foods.
Serum samples were tested by means of immunoblotting for IgE reactivities with proteins in extracts of birch pollen, apple, pear, celery, carrot, and potato. Anti-Bet v 1 and anti-Bet v 2 antibodies were used to investigate cross-reactivity. Inhibition studies were performed by preincubation of sera with recombinant Bet v 1 and Bet v 2.
IgE binding to proteins, corresponding to the major birch pollen allergen Bet v 1 and to Bet v 2 (birch pollen profilin) could be observed. An allergen homologous to Bet v 1 could be detected in apple, pear, and celery when a Bet v 1-specific monoclonal antibody was used. Testing a polyclonal rabbit anti-Bet v 2 antibody with extracts of the respective plants revealed the presence of profilins in every source tested. Inhibition with recombinant Bet v 1 and Bet v 2 led to complete blocking or marked reduction of IgE binding to proteins of comparable molecular weights in the respective food extracts, indicating IgE cross-reactivity.
Our results indicate that many plant-derived food agents contain proteins with high homology to the birch pollen allergens Bet v 1 and Bet v 2 and must therefore be considered as potentially threatening for patients with tree pollen allergy.
Birch pollinosis is often accompanied by allergy to fruits such as peach and apple. Bet v I is of major importance as cross-reactive allergen for this combined allergy. We studied a group of patients with combined grass pollinosis and fruit allergy from an area virtually without birch trees.
The aim of this study was to investigate the possible involvement of profilin and carbohydrate groups as cross-reactive structures in pollen and fruits.
RAST inhibition was performed to measure cross-reactive IgE to pollen and fruits. The presence of IgE against profilin was determined in a RAST with purified grass profilin, and IgE against carbohydrate structures was determined in a RAST with proteinase K-digested grass pollen extract. The biologic activity of IgE in response to profilin was tested by in vitro histamine release and skin prick tests.
IgE against fruits was shown to be largely cross-reactive with grass pollen. The majority of the patients had IgE against profilin (12 of 16) and carbohydrate structures (9 of 10). Profilin was shown to have biologic activity, in both histamine release and skin prick tests.
Profilin is an important allergen for patients with combined grass pollen/fruit allergy in areas without birch trees.
One hundred and twelve patients with a history of immediate adverse reaction after food ingestion and positive skin test to food are presented with the result of food challenge. In all patients the symptoms started after 10 years of age; most presented with recurrent short-lasting urticarial rash, often accompanied by rhinitis. In the majority of the patients, skin tests were positive to multiple food allergens, but 67% of these responded to oral provocation by only one allergen. One-third of the patients had a history of allergic symptoms following exercise after meals, but in only one-third of these symptoms were reproducible in the laboratory. Fruit and vegetables were the main allergens responsible for food hypersensitivity. Food allergy can develop after the first 10 years of life. Fruit and vegetables are the main cause of food allergy in these patients, while milk and egg are the least common. These findings differ from those in early childhood where milk and eggs are the main allergens.
This study assesses the value of two recombinant birch allergens for diagnosis of patients sensitized to birch pollen with or without associated food allergy.
Fifty-one patients with positive skin test responses to Betulaceae and seven nonallergic control subjects were investigated; specific IgE antibodies were evaluated by specific immunoassay and blot immunodetection.
Among 51 patients, 47 reacted to rBet v 1 and 10 to rBet v 2. Seven patients reacted to both recombinant allergens. In skin prick tests we found a correlation between the wheal produced by the commercial birch extract and the wheal produced by rBet v 1. Among 47 patients with positive test responses to rBet v 1, 83% had IgE binding to the Bet v 1 protein as determined by immunoblotting. Among 10 patients sensitized to rBet v 2, six had IgE binding to Bet v 2. Eleven patients with negative results, as determined by immunoblotting, had low levels of birch IgE in the sera (less than 10 kU/L) and low concentrations of IgE to rBet v 1 or rBet v 2 in ELISA. The nonallergic control subjects (n = 7) did not react to rBet v 1 or rBet v 2 in skin prick tests, nor did they have detectable amounts of specific IgE to rBet v 1 or rBet v 2. Histamine release tests confirmed sensitization to Bet v 1 in two patients with discordant results; for Bet v 2, one patient had positive results only at a high concentration, and one had results that remained negative. Thirty-four patients had birch pollinosis, and all reacted to rBet v 1. Patients who were monosensitized to birch never reacted to rBet v 2. Sensitization to rBet v 2 was only found in patients who reacted to other pollens (mainly grass). Twenty-nine patients demonstrated allergy to apples, cherries, or hazelnuts; and all reacted to rBet v 1. Among 11 patients with allergy to Umbelliferae, only three reacted to rBet v 2.
Use of the two recombinant allergens (rBet v 1 and rBet v 2) always permits the diagnosis of birch sensitization. Sensitization to rBet v 1 is specific for birch and Rosaceae allergies, whereas sensitization to birch profilin, Bet v 2, is encountered in multisensitized subjects and is not always related to Umbelliferae allergy.
Allergy to apple and Prunus fruits is frequently associated with birch pollinosis, with the principal cross-reacting allergens involved being members of the Bet v 1 family. However, a major 13-kd component, nonimmunologically related to Bet v 1, has been implicated as allergen in patients allergic to Prunoideae fruit but not to birch pollen.
We sought to isolate and characterize the 13-kd allergen present in apple and peach.
Sera from patients allergic to both fruits were selected on the basis of clinical symptoms, skin prick tests responses, and specific IgE levels. Allergens were purified by reverse-phase HPLC and characterized by N-terminal amino acid sequencing, MALDI analysis, specific IgE immunodetection, and immunoblot inhibition assays.
A 13-kd protein band was recognized in crude apple and peach extracts by 9 of 10 and 10 of 10 sera from patients allergic to fruit, respectively. The isolation and characterization of the corresponding allergens allowed their identification as lipid-transfer proteins, with a molecular mass of 9058 d for the apple protein and 9138 d for the peach protein. Both purified allergens were recognized by sera from patients allergic to fruit and fully inhibited the IgE binding by the 13-kd component present in the 2 crude fruit extracts.
Lipid-transfer proteins are relevant apple and peach allergens and, considering their ubiquitous distribution in tissues of many plant species, could be a novel type of panallergen of fruits and vegetables.
In this study, we determined by flow cytometry the percentage of basophils activated after in vitro stimulation by allergens and expressing the CD63 marker. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters.
Fifty-three patients suffering from asthma and/or allergic rhinitis following sensitization to Dermatophagoides pteronyssinus and 51 patients sensitized to Lolium perenne were investigated. Twenty-four atopic patients not sensitive to these allergens and 38 healthy subjects were also selected as controls. The basophil activation test determines the percentage of basophils which express CD63 as an activation marker, by means of flow cytometry, after in vitro stimulation with allergen, using double labelling with monoclonal antibody anti-CD63-PE and anti-IgE-FITC.
No differences in basal values (non-activated control) were found between sensitized patients, atopic controls and healthy controls. On the other hand, sensitized patients showed a significantly higher percentage of activated basophils after stimulation by allergens in vitro than both control groups (P < 0.001). We found a significant correlation between skin tests and basophil activation tests (r = 0.72, P < 0.001). We also found a positive and significant correlation between basophil activation tests and histamine release tests (r = 0.80, P < 0.001), allergen-specific sulphidoleukotriene production (r = 0.7, P < 0.001) and the occurrence of serum allergen-specific IgE (r = 0.71, P < 0.001).
The basophil activation test is a highly reliable technique in the diagnosis of allergy to inhalant allergens. The sensitivity of the basophil activation test was 93.3%, and its specificity 98.4%, when using a cut-off point of 15% activated basophils as positive result.
Individuals with pollen allergy often have IgE against plant-derived foods. This can be due to cross-reactive IgE against Bet v 1 and homologues, profilins, and/or cross-reactive carbohydrate determinants.
The aim of this study was to correlate sensitization to Bet v 1 and profilin with individual recognition patterns to plant foods and clinical relevance.
Fifty-two patients with pollen allergy and IgE against at least one plant-derived food were included in the study. Adverse reactions to plant-derived foods were documented by using standardized interviews. Skin prick tests were performed for pollen (grass, birch, and mugwort) and 14 plant-derived foods. In addition, recombinant (r) Bet v 1 and rBet v 2 (profilin) were tested intracutaneously. Specific IgE against the abovementioned allergens were determined by means of RAST. Cross-reactivity was studied by means of RAST inhibition.
Eighty-five percent of patients were sensitized to Bet v 1, and 71% were sensitized to profilin. Profilin was associated with a higher number of positive RAST results to plant-derived foods than Bet v 1. In contrast, Bet v 1 was associated with more positive skin prick test responses and more food-related symptoms. Sensitization to Bet v 1 was associated with IgE against apple, hazelnut, and peach, whereas sensitization to profilin was associated with positive RAST results to all investigated plant-derived foods except apple, peach, and melon.
IgE antibodies against Bet v 1 have a more limited spectrum of cross-reactivity than those against profilin, but they frequently give rise to clinically relevant cross-reactivities to food. In analogy to anticarbohydrate IgE, cross-reactive IgE against food profilins have no or very limited clinical relevance.
Food anaphylaxis is now the leading known cause of anaphylactic reactions treated in emergency departments in the United States. It is estimated that there are 30 000 anaphylactic reactions to foods treated in emergency departments and 150 to 200 deaths each year. Peanuts, tree nuts, fish, and shellfish account for most severe food anaphylactic reactions. Although clearly a form of immunoglobulin E-mediated hypersensitivity, the mechanistic details responsible for symptoms of food-induced anaphylaxis are not completely understood, and in some cases, symptoms are not seen unless the patient exercises within a few hours of the ingestion. At the present time, the mainstays of therapy include educating patients and their caregivers to strictly avoid food allergens, to recognize early symptoms of anaphylaxis, and to self-administer injectable epinephrine. However, clinical trials are now under way for the treatment of patients with peanut anaphylaxis using recombinant humanized anti-immunoglobulin E antibody therapy, and novel immunomodulatory therapies are being tested in animal models of peanut-induced anaphylaxis.
Several members of the plant non-specific lipid transfer protein (LTP) family have been identified as relevant allergens in foods and pollens. These allergens are highly resistant to both heat treatment and proteolytic digestion. These characteristics have been related with the induction of severe systemic reactions in many patients, and with the possibility of being primary sensitizers by the oral route. A specific geographical distribution pattern of sensitization to LTP allergens has been uncovered. This allergen family is particularly important in the Mediterranean area, but shows a very limited incidence in Central and Northern Europe. The potential role in the plant, as well as the biochemical and allergenic properties of the LTP family, are reviewed here.
To develop and evaluate a liquid phase immunoassay for accurate determination of allergen-specific IgE (sIgE) as a useful tool in the diagnosis of allergy patients.
A fully automated, quantitative sIgE assay was developed for the ADVIA Centaur technology platform using a unique calibration method based on a recombinant reference allergen. Compared to most other IgE-assays, the assay employs a reverse sandwich architecture using monoclonal mouse anti-human IgE antibody covalently bound to paramagnetic particles in the solid phase and capturing the sample IgE. Bound sIgE reacts with liquid biotin-labeled allergen, which is detected as chemiluminescence using acridiniumester-labeled streptavidin.
The ADVIA Centaur sIgE assay (Centaur assay) has exclusive reactivity to human IgE and performs with excellent linearity in the assay range 0.35-100 kU/L and high precision (imprecision within-run <2.6%, between-run <4.9%, and total imprecision <7.1%). The analytical sensitivity is <0.10 kU/L. Using Pharmacia CAP system FEIA (CAP) as a comparative method, positive/negative concordance was 94% at 0.35 kU/L cut-off, and the Centaur assay has a sensitivity of 90% and a specificity of 98%. Validation of the assay in a general population sample (The Copenhagen allergy study) revealed that sIgE was highly associated with a clinical diagnosis of inhalation allergy.
The Centaur assay is an allergen-specific assay for measurement of IgE without interference from other types of immunoglobulins or nonspecific IgE. The assay performs with a linear reaction, high assay range, and good reproducibility. The assay correlates well with the CAP system and is in agreement with clinical diagnosis.
The investigation of anaphylactic reactions in the peri-operative period is difficult. Elevation of serum tryptase levels is a good indicator of an anaphylactic event but the ability of subsequent investigations to identify the drug(s) responsible for the reaction is still potentially unreliable. The aim of this study was to examine basophil activation as an investigative tool. We performed flow cytometric analysis of the expression on the cell surface of the basophil activation markers CD63 and CD203c and measured histamine release in 21 patients who were referred with possible peri-operative anaphylaxis. The sensitivity of CD63, CD203c, basophil histamine release and skin prick for the muscle relaxants was found to be 79%, 36%, 36% and 64%, respectively; the specificity was found to be 100%. These results demonstrate the difficulty in investigating the cause of an unexpected clinical event following drug administration, but the higher sensitivity of neo-expression on the cell surface of CD63 suggests that flow cytometric analysis of its neo-expression on basophils in vitro may be a diagnostic aid.
Basophil activation is associated with the expression of CD63. In birch-pollen-associated food allergy to celery, carrot and apple, Bet v 1, Api g 1, Dau c 1 and Mal d 1 are major allergens. Recombinant allergens have not yet been used in the CD63-based basophil activation test (BAT).
To evaluate the feasibility of using recombinant allergens in the BAT in the diagnosis of allergy to apple, carrot and celery and to compare results with routine tests, i.e. skin prick tests (SPTs) and specific IgE.
Thirty-two patients with an oral allergy syndrome induced by apple, carrot or celery and 22 controls were studied. SPTs were performed with native foods. Specific IgE was determined by the CAP method and basophil activation by flowcytometry upon double staining with anti-IgE/anti-CD63 monoclonal antibodies after incubating with purified recombinant Bet v 1, Bet v 2, Api g 1, Dau c 1 and Mal d 1.
By the combined use of the BAT and the CAP method, sensitization to Bet v 1 and Bet v 2 was detected in 100 and 25% of all subjects, respectively. Sensitivity of specific IgE for apple, carrot and celery was 60, 70 and 75% with corresponding specificities of 64, 86 and 82%. Sensitivity of the BAT for Mal d 1, Dau c 1 and Api g 1 was 75, 65 and 75% with corresponding specificities of 68, 100 and 77%.
The BAT using recombinant allergens provides a valuable new in vitro method for the detection of sensitization to foods. Although double-blind placebo-controlled food challenges remain the gold standard to confirm food allergy, the CD63-based BAT with recombinant allergens may supplement routine tests for allergy diagnosis.
Results from several studies indicate that the magnitude of immediate symptoms of type I allergy caused by allergen-induced cross-linking of high-affinity Fc epsilon receptors on effector cells (mast cells and basophils) is not always associated with allergen-specific IgE levels.
To investigate the association of results from intradermal skin testing, basophil histamine release and allergen-specific IgE, IgG1-4, IgA and IgM antibody levels in a clinical study performed in birch pollen-allergic patients (n = 18).
rBet v 1-specific IgEs were measured by quantitative CAP measurements and by using purified Fc epsilon RI-derived alpha-chain to quantify IgE capable of binding to effector cells. Bet v 1-specific IgG subclasses, IgA and IgM levels were measured by ELISA, and basophil histamine release was determined in whole blood samples. Intradermal skin testing was performed with the end-point titration method.
Our study demonstrates on the molecular level that the concentrations of allergen-specific IgE antibodies capable of binding to Fc epsilon RI and biological sensitivities are not necessarily associated. A moderate association was found between cutaneous and basophil sensitivity.
Our results highlight the quantitative discrepancies and limitations of the present diagnostic tools in allergy, even when using a single allergenic molecule. The quantity of allergen-specific serum IgE is only one component of far more complex cellular systems (i.e. basophil-based tests, skin tests) used as indirect diagnostic tests for IgE-mediated allergic sensitivity.
Specific diagnosis of immediate type allergies, such as rhinoconjunctivis, asthma, urticaria/angioedema and anaphylaxis, particularly when IgE-mediated, traditionally rests on prick and/or intradermal skin tests and, since about 30 years, on the determination of allergen specific IgEs. Some cellular tests, i.e. tests determining the reactivity of blood cells in vitro, particularly basophils, to allergens, have been available for many years. The determination of histamine release has been widely used in allergy pathophysiological research but its routine application in allergy diagnosis has been restricted to few groups. Basophil degranulation, as determined by microscopic examination, was promoted by some groups in the 1980's but has been largely abandoned since around 10 years ago; an alternative cellular test, based on the determination of sulfidoleukotrienes (LTC4, LTD4, LTE4) produced by IL-3 primed basophils stimulated by allergens in vitro, has been proposed. This test became available commercially in 1993 under the name of CAST (Bühlmann Laboratories, Allschwil, Switzerland). The CAST assay has been used in allergy diagnosis in a variety of indications, such as inhalation allergies, allergies to insect venoms, foods, occupational allergens and various drugs. A large number of reports on CAST diagnostic value, however, have been anecdotal. A meta-analysis of validated and well controlled studies encompasses 37 studies, 1614 patients and 1145 controls. This should definitely establish the value of this diagnostic test, particularly in instances where other in vitro or in vivo diagnostic tests are not reliable, such as food or drug allergies, as well as in non-IgE-mediated immediate hypersensitivity reactions. However, a number of questions about the CAST diagnostic assay are still open or have not been systematically explored. This may explain, in addition to the practical limitations inherent to all allergy cellular tests, why CAST has not yet become a very widely used assay worldwide, having gained broad acceptance in some countries but not in others.
The peach lipid transfer protein Pru p 3 has been identified as a major allergen from this fruit. Homologous cross-reactive allergens have been found in several plant foods and pollens. Recombinant Pru p 3 has been recently produced in the yeast Pichia pastoris.
We sought to evaluate the potential role of recombinant Pru p 3 as a novel tool for the diagnosis of fruit allergy.
Circular dichroism analysis was used to compare the protein folding of natural Pru p 3 and recombinant Pru p 3. IgE binding by both molecular forms was quantified by means of ELISA and ELISA inhibition assays, and their biologic activity was estimated by using basophil activation, histamine release, and sulphidoleukotriene production tests. Individual sera or blood samples from patients with peach allergy (up to 17) were used in the assays.
A nearly identical circular dichroism spectra was shown by using natural Pru p 3 and recombinant Pru p 3, indicating that both protein forms are similarly folded. No difference was detected in the IgE-binding capacity of the 2 mo-lecular versions. Basophil activation and induction of sulphidoleukotriene production were positive in 9 of 10 patients, and histamine release was induced in at least half of the patients, with similar effects of the natural and recombinant forms in the 3 assays.
Recombinant Pru p 3 shows a strong immunologic activity equivalent to that of its natural counterpart, and therefore it can be a useful tool for diagnosis (and future immunotherapy) of fruit allergy.
This study describes the three-dimensional crystal structure of a non-specific lipid transport protein (ns-LTP) from Rosaceae. Whilst ns-LTPs from species other than Rosaceae, such as nuts, cereals, grape, oranges and vegetables are also responsible for plant food allergies, this is less frequent compared with ns-LTPs from Rosaceae in the Mediterranean area. In this heterologously expressed peach Pru p3, a ligand is present inside the central cavity of the protein, presumably a fatty acid that was present or produced in the culture medium of the expression organism Escherichia coli. Moreover, the two molecules of ns-LTP present in the asymmetric unit bind this ligand in a different way, suggesting a significant degree of plasticity for the peach ns-LTP binding cavity, despite the presence of four disulphide bridges. Two molecules are present in the asymmetric unit: molecule A is a fully liganded protein, while molecule B apparently represents a partially liganded state. Also, molecular dynamics simulation, along with other evidence, suggests that these two molecular conformations represent different states in solution. Comparison of the 3D models of different ns-LTPs justifies the evidence of a high degree of conservation of the putative IgE binding epitopes among proteins of the Rosaceae family and the presence of significant amino acid replacements in correspondence of the same regions in ns-LTPs of botanical species unrelated to Rosaceae.
There are no documented studies that describe natural rubber latex (NRL) sensitization in children with a history of surgical intervention but without any congenital malformation (urogenital anomalies, spina bifida, etc.), although some authors have studied NRL allergy in children without a history of surgical intervention. The aim of this work was to evaluate the sensitization profile to single NRL allergens in children without spina bifida and without repeated surgical interventions, by using different recombinant and natural latex allergens in two analytical techniques: specific serum immunoglobulin E (IgE) quantification and flow cytometry determination of activated basophils expressing CD63, after stimulating cells from patients with NRL allergens. A total of 23 patients and 10 healthy children were selected. Conjunctival and in-use NRL provocation tests were carried out, as well as specific IgE determination in all patients' and controls' sera with the recombinant NRL allergens: rHev b 1, rHev b 2, rHev b 3, rHev b 5, rHev b 6.01, rHev b 6.02, rHev b 8, rHev b 9 and rHev b 11 and with NRL (k82) using appropriate ImmunoCAPs. The Basophil Activation Test (BAT) was performed with whole latex extract and with the recombinant allergens rHev b 5 and rHev b 6.01, as well as with the natural allergen Hev b 6.02. The sensitivity and the specificity of NRL-specific IgE (k82) were 100%. Positive IgE responses to rHev b 5 were found in sera of 10 children, to rHev b 6.01 in 16 and for rHev b 6.02 in 15 children's sera. Specific IgE to rHev b 8 was found in four sera of the children. We only found significant differences in sensitization to rHev b 5 in children with two or more surgical interventions compared with the non-intervened group or those with only one intervention. Specific IgE in sera of children with latex-fruit syndrome recognized rHev b 6.02, but not to rHev b 11. The patients sensitized to Hev b 8, Hev b 9 and/or Hev b 11 were atopic. The four patients presenting a positive response to the NRL profilin Hev b 8 were allergic to pollen. The BAT against whole NRL extract was positive in 22 of 23 children; against rHev b 5 in 14 of the patients studied; against rHev b 6.01 in seven cases and against nHev b 6.02 in 19 children. In all the control subjects, the results using this technique were negative. If combined rHev b 5, rHev b 6.01 and nHev b 6.02 together, BAT could detect 20 of the 23 children with latex allergy. The combined use of ImmunoCAP with all the recombinant NRL allergens and BAT with rHev b 5, rHev b 6.01 and nHev b 6.02, enabled the identification of NRL allergy in 22 of 23 patients. There is a positive and significant correlation between sensitization to Hev b 5 and the number of interventions. BAT and allergen-specific IgE determination could be used as first-line in vitro diagnostic tests in patients with NRL allergy.
Food allergy to cherry occurs throughout Europe, typically with restricted oral reactions in the central and northern parts but with frequent systemic reactions in the Mediterranean region. Previous studies have demonstrated insufficient sensitivity of commercially available cherry extract reagents in the diagnosis of cherry allergy.
To assess the diagnostic performance of specific IgE tests based on recombinant cherry allergens in comparison with an extract-based assay and to skin prick test (SPT). A secondary objective was to analyse the frequency of systemic reactions in cherry-allergic subjects across Europe, including the largest population of LTP-sensitized subjects from central Europe studied to date.
A total of 186 subjects from central Europe and Spain were studied. Serum IgE was analysed with ImmunoCAP tests carrying rPru av 1, 3 and 4, combined and separately, and cherry extract.
Among the central European cherry allergics, the mix of rPru av 1, 3 and 4 had a sensitivity of 95%, compared with 65% for cherry extract, and the IgE binding capacity of the recombinant mix was considerably higher. The sensitivity of the two tests was more comparable in the Spanish population, 95% and 86%, respectively. The recombinant allergen ImmunoCAP equalled SPT in terms of sensitivity and specificity. Consistent with previous reports, major geographic differences in sensitization pattern and prevalence of systemic reactions were found. A significantly higher rate of systemic reactions was found in Spanish patients sensitized to Pru av 3 whereas German patients sensitized to LTP only had oral allergy syndrome.
The recombinant cherry allergen ImmunoCAP is a highly sensitive diagnostic tool, clearly superior to any diagnostic method based on cherry extract. Three cherry allergens are sufficient for detecting sensitization in 95% of cherry-allergic subjects. Systemic reactions are common in LTP-sensitized individuals but seem to require at least one additional causative factor.
Profilins are cross-reactive plant allergens responsible for multiple pollen sensitization and pollen-associated food allergy. While it is assumed that profilins from different species are immunologically equivalent, some studies suggest partial or even lacking IgE cross-reactivity between certain profilins.
We aimed to obtain a semi-quantitative assessment of the contributions of conserved and species-specific epitopes to IgE binding of plant profilins.
We compared model structures of profilins from timothy, mugwort, celery and bell pepper with crystal structures of birch and latex profilins. We predicted potential conformational epitopes that consisted of contiguous patches of at least 20% surface-exposed residues. Celery and timothy profilins were purified from their natural sources, and profilins from birch, mugwort, bell pepper and latex were expressed in Escherichia coli. The structural integrity of all purified proteins was confirmed by circular dichroism spectroscopy. IgE ELISAs and ELISA inhibitions using sera from 22 profilin-sensitized allergic patients were carried out.
Peptide backbone conformations of all six profilins were highly similar. Nine variable epitopes and two containing high proportions of conserved residues were predicted. IgE from all sera bound to all tested profilins and the amounts were highly correlated. However, IgE inhibition experiments revealed that up to 60% of total IgE binding was mediated by species-specific epitopes. The extent of cross-reactivity among profilins from timothy, birch, latex and celery was greater than cross-reactivity to mugwort and bell pepper profilins. This pattern was mirrored by sequence similarities among one of the predicted variable epitopes. Patients with IgE to cross-reactive epitopes displayed allergic reactions to a greater number of plant foods than patients having IgE directed to species-specific epitopes.
The large extent of cross-reactivity among plant profilins justifies using a single profilin for diagnosis. However, the fine specificity of IgE directed to variable epitopes may influence the clinical manifestation of profilin sensitization.
Allergy to a plant food can either result from direct sensitization to that food or from primary sensitization to pollen, latex, or another food.
We sought to investigate the primary sensitizers in apple allergy across Europe, the individual allergens involved, and whether these differences determine the clinical presentation.
Patients (n = 389) with positive case histories and skin prick test responses to fresh apple were selected in the Netherlands, Austria, Italy, and Spain. Skin prick tests and RASTs to a panel of pollens and plant foods were performed, as well as RASTs to Bet v 1 and the apple allergens Mal d 1, 2, 3, and 4.
In the Netherlands, Austria, and Italy apple allergy is mild (>90% isolated oral symptoms) and related to birch pollinosis and sensitization to Bet v 1 and its apple homologue, Mal d 1, which has an odds ratio of local reactions of 2.85 (95% CI, 1.47-5.55). In Spain apple allergy is severe (>35% systemic reactions) and related to peach allergy and sensitization to Mal d 3 (nonspecific lipid transfer protein), which has an odds ratio of systemic reactions of 7.76 (95% CI, 3.87-15.56).
The analysis of individual apple allergens in a clinical context has provided insight into the sensitization pathway and into the intrinsic risk an allergen bears to induce mild or severe food allergy.
Information on the sensitization pathway is essential to develop preventive strategies in food allergy. The application of individual food allergens with a known intrinsic risk will improve the prognostic value of diagnostic tests.
Sensitization to peach and related Rosaceae fruits without clinical expression is commonly observed as the result of the extensive cross-reactivity of IgE antibodies directed toward lipid transfer proteins (LTPs), Bet v 1 homologues, profilins, and carbohydrate determinants.
We aimed to study whether there are any clinical or immunologic differences between patients allergic to peach and those who have a current clinically irrelevant sensitization to this fruit.
One hundred subjects with adverse reactions to peach were evaluated by medical history, skin prick tests with fresh peach and purified peach LTP (Pru p 3), and specific IgE determinations to peach, rBet v 1, and rBet v 2 (birch profilin). Clinical reactivity to peach was established by double-blind, placebo-controlled food challenges. The clinical characteristics and the in vivo and in vitro tests were compared between allergic and nonallergic patients.
Peach allergy was confirmed in 76 patients and ruled out in 16; 2 patients dropped out, and the study was not conclusive in 6 individuals (placebo reactors). Pollen allergy was found in 76% of the allergic patients and in 100% of the nonallergic patients. Positive responses to Pru p 3, rBet v 1, and rBet v 2 were observed in 62%, 7%, and 34% of patients allergic to peach, respectively. The sensitization rate to Pru p 3 was significantly higher among subjects allergic than nonallergic to peach (62% vs 31%, P =.02). IgE responses to rBet v 2 were more frequent among subjects allergic to pollen, but no difference was observed in the presence or absence of peach allergy.
Pru p 3 is the major allergen of peach in our population, and the IgE response to this allergen is related to the clinical expression of peach allergy. Sensitization to profilin is observed in those patients with an associated pollen allergy but does not appear to be related to the clinical reactivity to peach.
Cuáles son los pólenes que producen polinosis en el medio urbano de Madrid
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- Gavilan MJ
- Varela S
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- Narganes MJ
- Subiza J
- Jerez M
- Gavilan MJ
- Varela S
- Rodríguez R
- Narganes MJ
Estudio de la polinización en el área de Bilbao en 1995. Actualización de los estudios de sensibilización a pólenes en la población
- Antepara I
- Fernandez Martinez I
- Jauregui I
- Egusquiaguirre C
- Fernandez Galdeano L
- Gamboa PM
- Antepara I
- Fernandez Martinez I
- Jauregui I
- Egusquiaguirre C
- Fernandez Galdeano L
- Gamboa PM
Estudio de la polinizacio´polinizacioé el a´ de Bilbao en 1995. Actualizacio´ los estudios de sensibilizacio´sensibilizacioá pó lenes en la poblacio´
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- I Martinez
- I Jauregui
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- L Galdeano
- Gamboa
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Estudio de la polinizacio´n en el a´rea de Bilbao en 1995. Actualizacio´n de los estudios de sensibilizacio´n a pó lenes en la poblacio´n
- I Antepara
- Fernandez Martinez
- I Jauregui
- I Egusquiaguirre
- Fernandez Galdeano
- L Gamboa
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Jauregui I, Egusquiaguirre C, Fernandez
Galdeano L, Gamboa PM. Estudio de la
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IgE to Bet v 1 and profilin: cross-reactivity patterns and clinical relevance
- M Wensing
- Jh Akkerdaas
- A Van Leeuwen
- So Stapel
- Cafm Brujinzeel-Koomen
- Rc Aalberse
Wensing M, Akkerdaas JH,
van Leeuwen A, Stapel SO, Brujinzeel-
Koomen CAFM, Aalberse RC et al.
IgE to Bet v 1 and profilin: cross-reactivity patterns and clinical relevance.
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435–442.
Patterns of reactivity to lipid transfer proteins of plant foods and Artemisa pollen: an in vivo study
- Fj Garcia-Selles
- Diaz Perales
- A Sanchez-Monge
- R Alcantara
- M Lombardero
- M Barber
- D Etal
Identification of allergens in fruits and vegetables. IgE-cross reactivity with important birch pollen allergens Bet v1 and Bet v 2 (birch profillin)
- C Ebner
- R Hirschwehr
- L Bauer
- H Breiteneder
- R Valenta
- H Ebner
- Etal
Apple allergy across Europe: how allergen sensitization profiles determine the clinical expression of allergies to plant foods
- M Fernández-Rivas
- S Bolhaar
- E González-Mancebo
- R Assero
- A Van Leeuwen
- B Bohle
- Etal
Allergen-induced basophil activation: CD63 cell expression detected by flow cytometry in patients allergic to Dermatophagoides pteronyssinus and Lollium perenne
- Ml Sanz
- G Sánchez
- Pm Gamboa
- L Vila
- C Uasuf
- M Chazot
- Etal
Crystal structure of peach Pru p 3, the prototypic member of the family of plant non-specific lipid transfer protein pan-allergens
- N Pasquato
- R Berni
- C Folli
- S Folloni
- M Cianci
- S Pantano
- Etal
Skin testing with recombinant allergens rBet v 1 and birch profilin, rBet v 2: diagnostic value for birch pollen and associated allergies
- G Pauli
- Jp Oster
- P Deviller
- S Heiss
- Jc Bessot
- M Susani
- Etal
Basophil activation test and specific IgE measurements using a panel of recombinant natural rubber latex allergens to determine the latex allergen sensitization profile in children
- Ml Sanz
- Mc García-Avilés
- Ai Tabar
- M Anda
- Be García
- D Barber
- Etal
Cuáles son los pólenes que producen polinosis en el medio urbano de Madrid
- Subiza J
Estudio de la polinización en el área de Bilbao en 1995. Actualización de los estudios de sensibilización a pólenes en la población
- Antepara I