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Background:
Little is known about the prevalence and clinical relevance of hypersensitivity to the plant panallergen profilin in children.
Objectives:
The present study aimed to investigate prevalence, risk factors and clinical relevance of profilin sensitization in a large cohort of Italian children of different ages living in different geograp...
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Introduction
Allergies affect 20-30% of the population and respiratory allergies are mostly due to pollen grains from anemophilous plants. One to 5% of people suffer from food allergies and clinicians report increasing numbers of pollen-food allergy syndrome (PFAS), such that the symptoms have broadened from respiratory to gastrointestinal, and eve...
Citations
... Regarding plant food allergy, it was found that PR10 allergic patients with profilin co-sensitization have more frequent OAS (46) and profilin sensitization was reported to be important for OAS especially in childhood (47). Several other studies including our current study support the role of profilin as a clinically important allergen. ...
Pollen from Salsola kali, i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. S. kali-allergic patients mainly suffer from hay-fever (i.e., rhinitis and conjunctivitis), asthma, and allergic skin symptoms. The aim of this study was to investigate the importance of individual S. kali allergen molecules. Sal k 1, Sal k 2, Sal k 3, Sal k 4, Sal k 5, and Sal k 6 were expressed in Escherichia coli as recombinant proteins containing a C-terminal hexahistidine tag and purified by nickel affinity chromatography. The purity of the recombinant allergens was analyzed by SDS-PAGE. Their molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and their fold and secondary structure were studied by circular dichroism (CD) spectroscopy. Sera from clinically well-characterized S. kali-allergic patients were used for IgE reactivity and basophil activation experiments. S. kali allergen-specific IgE levels and IgE levels specific for the highly IgE cross-reactive profilin and the calcium-binding allergen from timothy grass pollen, Phl p 12 and Phl p 7, respectively, were measured by ImmunoCAP. The allergenic activity of natural S. kali pollen allergens was studied in basophil activation experiments. Recombinant S. kali allergens were folded when studied by CD analysis. The sum of recombinant allergen-specific IgE levels and allergen-extract-specific IgE levels was highly correlated. Sal k 1 and profilin, reactive with IgE from 64% and 49% of patients, respectively, were the most important allergens, whereas the other S. kali allergens were less frequently recognized. Specific IgE levels were highest for profilin. Of note, 37% of patients who were negative for Sal k 1 showed IgE reactivity to Phl p 12, emphasizing the importance of the ubiquitous cytoskeletal actin-binding protein, profilin, for the diagnosis of IgE sensitization in S. kali-allergic patients. rPhl p 12 and rSal k 4 showed equivalent IgE reactivity, and the clinical importance of profilin was underlined by the fact that profilin-monosensitized patients suffered from symptoms of respiratory allergy to saltwort. Accordingly, profilin should be included in the panel of allergen molecules for diagnosis and in molecular allergy vaccines for the treatment and prevention of S. kali allergy.
... 15 To address this important diagnostic issue, the Italian Pediatric Allergy Network started Panallergens in Pediatrics (PAN-PED), a clinical survey of 1360 Italian children affected by SAR. 16 The project investigated the complexity of IgE molecular sensitization profiles of grass pollen-allergic children, 17 the relevance of profilins and polcalcins for SAR comorbidities, 5,18 the role of profilin, PR-10s and nonspecific lipid transfer protein (nsLTP) in pollen food allergy syndrome, 19 the relevance of IgE to crossreactive carbohydrate determinants (CCD) in childhood, 20 and the effect of molecular diagnosis on the prescription of AIT. 21 These studies of the PAN-PED cohort also revealed a high prevalence (around 10%) of patients with a ''falsely'' positive skin prick test (SPT) result to birch pollen extract-that is, a positive SPT reaction in patients lacking IgE to Bet v 1 (birch's PR-10 and major allergen molecule). ...
... A study in Spain has showed 56% of date palm pollenallergic patients had a specific IgE-reactivity to natural profilin Pho d 2. 34 Positive SPT to the date palm pollen profilin was also observed among 25% of pollen-allergic children in Italy. 35 In the present study, the frequency of SSIgE sensitization against Ela g profilin (>0.35IU/ml) in the oil palm-sensitized individuals was not significantly higher than the non-sensitized controls (p ¼ 0.076). This suggests the Ela g profilin is not a major allergen of the oil palm pollen. ...
Background
Elaeis guineensis (Ela g, oil palm) pollen is one of the most predominant species of inhalant allergens in the tropical Southeast Asia region; however, its association with the manifestation of allergic diseases remains largely unexplored. This study aimed to determine the sensitization pattern of oil palm pollen and associate this with the risk and severity of allergic diseases.
Methods
Participants were recruited as a part of the Singapore and Malaysia cross-sectional genetic and epidemiological study (SMCSGES). Two independent cohorts were recruited: n = 564 serum samples were collected and serological assessment was performed against a panel of 16 crude inhalant allergens including house dust mite, pet, insect, pollen, and fungal allergens; n = 13 652 Singapore/Malaysia Chinese young adults were recruited and skin prick test was used to assess oil palm sensitization, which was tested for its association with the risk and severity of asthma, allergic rhinitis (AR), and atopic dermatitis (AD).
Results
The sensitization rate of oil palm pollen is 9.6% in the n = 564 Singapore/Malaysia cohort. In the n = 13 652 Singapore/Malaysia Chinese cohort, oil palm sensitization significantly associates with increased risks of asthma (p = 1.34x10⁻⁴), AR (p = 2.91x10⁻¹³), and AD (p = 6.95x10⁻⁷). Asthmatic patients with oil palm sensitization have increased risks of wheezing (p = 0.00995), nocturnal cough (p = 0.0122), and exacerbations (p = 0.00139) in the past 12 months. AR patients with oil palm sensitization also have an increased risk of developing moderate-to-severe symptoms (p = 0.00113).
Conclusions
We have identified significant associations of oil palm sensitization with increased risks, exacerbations, and the severity of symptoms of allergic diseases in the tropical Southeast Asian region (Singapore/Malaysia).
... Sensitization to profilin is mainly associated with grass pollen allergy, whereas its clinical relevance for developing allergy to multiple pollen species or to natural rubber latex is low (Rodriguez Del Rio et al., 2018). About half of profilin-sensitized patients show allergic reactions to plant foods, with melon, watermelon, citrus fruits, banana, and tomato being specifically associated with profilin sensitization (Asero et al., 2008(Asero et al., , 2015. These allergic reactions are in most cases confined to mild, oropharyngeal symptoms and occur only after ingesting raw foods. ...
In recent decades, a large number of food allergens have been identified and characterized. This knowledge has allowed great progress in the elucidation of the mechanisms of allergic sensitization and the effector phase, as well as improvements in allergy diagnosis and allergen immunotherapy. Most food allergens can be classified into a small number of protein families based on evolutionary relatedness. This classification has provided insights into the molecular basis of cross-reactivity and the features that contribute to the allergenicity of certain proteins. In this article, we provide the reader with an overview of the major families of food allergens.
... 108 Allergies to apples, peaches, pears, and strawberries have been associated with this type of sensitization. 109 In the case of vegetable allergies, profilin is considered a significant sensitizer for individuals allergic to celery, while its impact is minor in carrot allergies. 2 The prevalence of profilin sensitization is evenly distributed but more common in the Mediterranean region. 2 Biotic and abiotic stressors contribute to the production of thaumatin-like proteins (TLPs), which possess a rigid three-dimensional structure formed by eight disulfide bridges from cysteine residues. ...
... 108 When symptomatic, the main clinical manifestation is OAS, with a low to moderate risk of a systemic allergic response. 109 Kiwifruit allergies can be initiated either through primary sensitization due to gastrointestinal food allergy or through cross-reactivity with allergens from birch or grass pollens and latex. This cross-reactivity occurs because of a similar protein found in kiwifruit, which bears a resemblance to Hev b 11, a latex chitinase. ...
... 108 Allergies to apples, peaches, pears, and strawberries have been associated with this type of sensitization. 109 In the case of vegetable allergies, profilin is considered a significant sensitizer for individuals allergic to celery, while its impact is minor in carrot allergies. 2 The prevalence of profilin sensitization is evenly distributed but more common in the Mediterranean region. 2 Biotic and abiotic stressors contribute to the production of thaumatin-like proteins (TLPs), which possess a rigid three-dimensional structure formed by eight disulfide bridges from cysteine residues. ...
... 108 When symptomatic, the main clinical manifestation is OAS, with a low to moderate risk of a systemic allergic response. 109 Kiwifruit allergies can be initiated either through primary sensitization due to gastrointestinal food allergy or through cross-reactivity with allergens from birch or grass pollens and latex. This cross-reactivity occurs because of a similar protein found in kiwifruit, which bears a resemblance to Hev b 11, a latex chitinase. ...
... The majority of patients with banana allergy in our study were clinically allergic to more than two plant foods, with the vast majority reporting non-severe reactions to other plant foods. Structural proteins known as profilins, such as Mus a 1 in bananas, are epitopes that act as pan-allergens and can cross-react with various fruits, including melon, watermelon, tomato, banana, pineapple, kiwi, apricot, and citrus fruits [10,[33][34][35][36]. They can also cross-react with tropical and exotic fruits like persimmon [36] and mango profilin [33]. ...
... Structural proteins known as profilins, such as Mus a 1 in bananas, are epitopes that act as pan-allergens and can cross-react with various fruits, including melon, watermelon, tomato, banana, pineapple, kiwi, apricot, and citrus fruits [10,[33][34][35][36]. They can also cross-react with tropical and exotic fruits like persimmon [36] and mango profilin [33]. Sensitization to pollen profilins only occurs in a minority of patients, and allergic reactions are typically mild, manifesting as symptoms limited to the oropharynx, referred to as oral allergy syndrome. ...
This cross-sectional study aimed to investigate the prevalence and clinical characteristics of cross-reactivity and co-allergy to other plant foods among adult patients with IgE-mediated banana allergy in Thailand. A structured questionnaire was used to assess clinical reactivity, and cross-reactivity diagnoses were based on reactions occurring within 2 years of banana allergy onset, within 3 h of intake, and confirmed by allergists. Among the 133 participants, the most commonly associated plant foods with clinical reactions were kiwi (83.5%), avocado (71.1%), persimmon (58.8%), grapes (44.0%), and durian (43.6%). Notably, 26.5% of the reported reactions to other plant foods were classified as severe. These findings highlight the common occurrence of cross-reactivity/co-allergy to other plant foods in banana-allergic patients, with a significant proportion experiencing severe reactions. Travelers to tropical regions should be aware of this risk and advised to avoid specific banana cultivars and plant foods with reported high cross-reactivity. The inclusion of self-injectable epinephrine in the management plan for patients with primary banana allergy should be considered due to the substantial proportion of reported severe reactions and the wide range of clinical cross-reactivity and co-allergy observed.
... Sensitization to CCDs, profilins and polcalcins has been reported in about 22%-35%, 2-4 13%-50%, [5][6][7][8] and 8%-10%, 4,5,9 respectively, with considerable variability depending on geographical regions and patient populations investigated. Nevertheless, the significant risk of misdiagnosis when using extract-based diagnostic tests may have been underestimated because determining a wide range of molecular allergens or blocking of sIgE to CCDs was not routinely performed. ...
Background:
The specificity of extract-based pollen allergy diagnosis is decreased due to cross-reactivity via cross-reactive carbohydrate determinants (CCDs) or panallergens such as profilins or polcalcins. This study aimed to explore the prevalence of sensitization to seasonal extracts, CCDs, profilin and polcalcin and investigate the sensitivity and specificity of seasonal molecular allergy diagnosis (MAD) using commercially available test methods.
Methods:
2948 patients were screened for specific immunoglobulin E to ash, birch, mugwort, ragweed and timothy grass pollen extracts and grouped according to the number of positive tests (1-5). 100 patients from each group and a control group were randomly selected to calculate the prevalence of CCD and panallergen sensitization. With 742 patients, sensitivity and specificity of MAD (Alt a 1, Fra/Ole e 1, Bet v 1, Phl p 1, Art v 1, and Amb a 1) was determined.
Results:
1627 patients (55.2%) were positive to at least one, and 1002 patients (34.0%) were positive to multiple of the five pollen allergens investigated; 18.5% of the pollen-sensitized patients had sensitization to CCDs or panallergens. Specifically, sensitization to CCDs, profilins, and polcalcins was observed in 8.7%, 10.9%, and 2.9% of these patients, respectively. The sensitivity of MAD was high, with sensitivities between 96.2% and 100% using ImmunoCAP and 91.5% and 100% using ALEX2 . Specificity was 100% for both assays.
Conclusions:
Due to cross-reactivity, about one-fifth of pollen-sensitized patients is at risk of misdiagnosis. However, MAD is sensitive, specific and helps to avoid misdiagnosis and select primary allergen sources for immunotherapy.
... Most pollen allergic children get sensitized first to major, species-specific allergens, whereas sensitization to cross-reactive allergens, including profilins, usually occurs later (Hatzler et al., 2012;Westman et al., 2020). Accordingly, sensitization to profilin and polcalcin correlated with a longer history of pollen allergy (Barber et al., 2009;Asero et al., 2015). As expected from its high extent of cross-reactivity, sensitization to profilin was associated with sensitization to multiple pollen species as measured by skin prick test, but the clinical reactivity of the patients correlated primarily with the reactivity to major allergens (Mari, 2001;San Nicolo et al., 2016). ...
... The clinical data matched the observation that profilin-containing airborne pollen was detected in much of the pollen season thereby exacerbating the allergen exposure for profilin-sensitized patients (Ruiz-Hornillos et al., 2020). In contrast, profilin-sensitized pollen-allergic children from Italy showed no increase in symptom severity or the number of symptomatic days (Asero et al., 2015). In conclusion, the question to which extent sensitization to profilin contributes to symptoms of pollen allergy remains controversial. ...
... Later studies with large numbers of patients, however, revised this conclusion. It appeared that sensitization to profilin increases the risk of plant food allergy, both in children and adults, with about half of profilin-sensitized pollen-allergic patients affected by plant food allergy (Asero et al., 2008(Asero et al., , 2015. In patients sensitized to other cross-reactive allergens associated with plant food allergy, i.e. ...
... Thus, profilin is considered to be responsible for the allergic cross-reactivity between these products [38]. Interestingly, it was also suggested that profilin might indicate allergy outcome and severity [41][42][43][44]. Moreover, naturally purified profilin may be used for the desensitization treatment of profilin-induced food allergy [45]. ...
Bee pollen, because of its high content of nutrients, is a very valuable medicinal and nutritional product. However, since its composition is not completely studied, the consumption of this product may cause adverse effects, including allergic reactions. Therefore, this study aimed to discover and characterize the bioactive proteins of bee pollen collected in Poland, focusing mainly on the allergens. For this purpose, the purified and concentrated pollen aqueous solutions were analyzed using the nanoLC-MALDI-TOF/TOF MS analytical platform. As a result of the experiments, 197 unique proteins derived from green plants (Viridiplantae) and 10 unique proteins derived from bees (Apis spp.) were identified. Among them, potential plant allergens were discovered. Moreover, proteins belonging to the group of hypothetical proteins, whose expression had not been confirmed experimentally before, were detected. Because of the content of bioactive compounds—both beneficial and harmful—there is a critical need to develop guidelines for standardizing bee pollen, especially intended for consumption or therapeutic purposes. This is of particular importance because awareness of the allergen content of bee pollen and other bee products can prevent health- or life-threatening incidents following the ingestion of these increasingly popular “superfoods”.
