Krzysztof Fyderek

Jagiellonian University | UJ · Department of Pediatrics

Magnetic resonance enterography (MRE) is a commonly used method for non-invasive diagnosing and following of inflammatory bowel disease (IBD). Numerous reviews that compare and discuss MRE-based Crohn's disease (CD) activity indices for adults have been published; however, no reviews of this kind have been published for children. Following a PubMed...

The worldwide surge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic and led governments to control spread of the virus and provide care for the population affected by the infection. Although, in children, COVID-19 is usually asymptomatic or mild (except PIMS), the pandemic affected the whole socioeconomi...

Mucosal healing (MH) is the main therapeutic goal of Crohn’s disease (CD). The Mucosal Inflammation Noninvasive Index (MINI) appears to be a promising tool for distinguishing MH from its inflammation. This study aims to evaluate MINI in monitoring remissions induced by exclusive enteral nutrition (EEN) in pediatric CD patients. Out of 55 newly diag...

Introduction: Mucosal healing (MH) has become a therapeutic goal in Crohn's Disease (CD), but its frequent evaluation in endoscopic examination is fraught with several limitations. There is an increasing demand to replace invasive procedures with noninvasive markers of CD. Aim: To assess the clinical importance of the recently developed Mucosal...

Introduction The aim of our study was to assess antimicrobial peptides in children with Crohn’s disease (CD). Material and methods Plasma elafin, cathelicidin, alpha and beta-defensins were assessed in 35 children with CD using immunoassays. Phenotype and location of CD were assessed based on the results of endoscopic and radiology studies. Resul...

Autoimmune diseases, including autoimmune thyroid diseases (AITDs), may be associated with Crohn's disease (CD). Taking into consideration the role of tumor necrosis factor alpha (TNF-alpha) in the immune-mediated inflammation that underlies both diseases, we evaluated an ultrasound of thyroid gland in pediatric CD patients, naïve, and treated with...

Purpose The aim of this study was to determine quantitative changes in selected species of bacteria (Bacteroides fragilis, Lactobacillus fermentum, Lactobacillus rhamnosus, Serratia marcescens) in the stool of patients with Crohn's disease (CD) in the course of induction treatment with exclusive enteral nutrition (EEN) or anti-tumor necrosis factor...

The aim of the study was to determine the impact of biological treatment with tumor necrosis factor α antibodies (anti-TNF-α) on the intestinal microbiome of children with severe Crohn's disease (CD) and to evaluate the differences in the intestinal microbiome between patients treated with biological therapy and healthy children. Microbiota composi...

Very-early-onset inflammatory bowel disease (VEO-IBD) is a heterogeneous phenotype associated with a spectrum of rare Mendelian disorders. Here, we perform whole-exome-sequencing and genome-wide genotyping in 145 patients (median age-at-diagnosis of 3.5 years), in whom no Mendelian disorders were clinically suspected. In five patients we detect a p...

Background and study aims: The aim of the study was to assess the usefulness of serum concentrations of YKL-40/ CHI3L1 (a 40-kilodalton glycoprotein also referred to as chitinase 3 like- 1 - CHI3L1) and PIIINP (N-terminal propeptide of type III procollagen), markers of fibrosis, in the monitoring of inflammatory processes and fibrosis in children...

The aetiology of inflammatory bowel diseases (IBD) seems to be strongly connected to changes in the enteral microbiome. The dysbiosis pattern seen in Crohn’s disease (CD) differs among published studies depending on patients’ age, disease phenotype and microbiome research methods. The aims was to investigate microbiome in treatment-naive paediatric...

Introduction: Inflammatory bowel disease (IBD), a chronic inflammatory disorder of gastrointestinal tract, arises from complex interaction between genetics, environment, gut microbiota and mucosal immune response. Along with clinical, endoscopic and radiological evaluation various biomarkers are needed as an additional diagnostic tool, as well as...

The aim of this study was to determine if there are quantitative differences in Candida fungi between pediatric patients with Crohn’s disease (before and after exclusive enteral nutrition (EEN), and the biologic therapy with anti-tumor necrosis factor alpha – (IFX)), and healthy controls. DNA was isolated from fecal samples and PCR was used to dete...

Crohn's disease (CD) is a chronic, inflammatory illness of the digestive tract, characterized by alternating periods of remission and recurrence. The pathogenesis of CD is still unclear but probably is a result of a complex interaction between immunological, genetic and microbiological disorders. In recent years, there has been an increasing extent...

Genetic defects that affect intestinal epithelial barrier function can present with very early-onset inflammatory bowel disease (VEOIBD). Using whole-genome sequencing, a novel hemizygous defect in NOX1 encoding NAPDH oxidase 1 was identified in a patient with ulcerative colitis-like VEOIBD. Exome screening of 1,878 pediatric patients identified fu...

A new bioactive compound, Mn 3+-saturated bovine lactoferrin (Mn 2-bLf) was obtained. It was stable under physiological conditions (pH % 7.5) although gradually releases Mn 2+ ions under the simulated intestinal conditions (pH % 6.5). This feature might be utilized for controlled delivery of Mn 2+ ions to biological targets, among others to the pro...

A new bioactive compound, Mn 3+-saturated bovine lactoferrin (Mn 2-bLf) was obtained. It was stable under physiological conditions (pH % 7.5) although gradually releases Mn 2+ ions under the simulated intestinal conditions (pH % 6.5). This feature might be utilized for controlled delivery of Mn 2+ ions to biological targets, among others to the pro...

Introduction: Chronic inflammation present in Crohn's disease, absorptive disorders, dietary self-restrictions imposed to avoid symptoms - all lead to chronic malnutrition. Aim: The aim of the study was to assess the nutritional status and habits of patients before Exclusive Enteral Nutrition (EEN) therapy and during remissions. Materials and metho...

i>Introduction: Chronic abdominal pain in children is a very frequent and sometimes challenging diagnostic issue. Differential diagnosis in that cases is difficult and often connected with numerous, time-consuming, expensive, and frequently stressful diagnostic studies. The aim of the study was to establish whether fecal calprotectin concentration...

Introduction Interleukin-1β (IL-1β), interleukin-1 receptor antagonist (IL-1ra) and interleukin-6 (IL-6) contribute to the pathogenesis of ulcerative colitis (UC). The aim of our study was to evaluate the serum and stool IL-1β, IL-1ra and IL-6 concentrations as potential prognostic factors in children with UC. Material and methods Thirty-eight chi...

Over the past years, there is a growing number of newly diagnosed pediatric patients with Crohn's disease (CD). Severe course of CD often requires biological treatment with Infliximab (IFX). Loss of response to biological treatment is a major problem. Mean platelet volume (MPV) was reported as a good marker of sustained response to IFX therapy in a...

In this review issues concerning bone metabolism are presented. The diagnostic criteria of decreased mineral bone density is discussed with the significance of densitometry. The necessity of presence of low-trauma fracture to diagnosed the osteoporosis in children is signified. The paper reviews most common chronic gastrointestinal tract condition...

Background/aims: To evaluate the characteristic properties of laryngopharyngeal reflux (LPR) and gastroesophageal reflux (GER) in children with otitis media with effusion (OME) using 24-hour multichannel intraluminal impedance combined with dual-probe (pharyngeal and esophageal) pH-metry. Methods: Children aged 7-10 years of age with OME underwe...

For many years vitamin K has been considered to be associated only with blood clotting processes. Thanks to the research of last thirty years its other equally important role has been discovered. Vitamin K acts as a cofactor for the posttranslatioinal γ-carboxylation of glutamate residues in proteins such as osteocalcin or matrix Gla protein (MGP)....

Goodness-of-fit and diagnostic plots for the final model in children and adolescents: plasma 5-ASA. Notes: The dashed line represents the local regression (Loess) smoothing line. (A) Observed versus population predicted concentration; (B) observed versus individual predicted concentration; (C) conditional weighted residual versus population predict...

Goodness-of-fit and diagnostic plots for the final model in children and adolescents: plasma Ac-5-ASA. Notes: The dashed line represents the local regression (Loess) smoothing line. (A) Observed versus population predicted concentration; (B) observed versus individual predicted concentration; (C) conditional weighted residual versus population pred...

Schematic of final population pharmacokinetic structural model. Notes: Numbers on the top left-hand corner of the boxes represent the compartment numbers for the population pharmacokinetic model in the NONMEM code. Hence, the two depot compartments were denoted as depot 1 and depot 3. Abbreviations: ALAG1, absorption lag time from depot 1; 5-ASA, 5...

Background Limited data are available on mesalamine (5-aminosalicylic acid; 5-ASA) use in pediatric ulcerative colitis (UC). Aim To evaluate pharmacokinetic and safety profiles of 5-ASA and metabolite acetyl-5-ASA (Ac-5-ASA) after once-daily, oral administration of multimatrix mesalamine to children and adolescents with UC. Methods Participants (...

Objectives . The aim of the study was to establish whether fecal calprotectin concentration (FCC) may be useful in children with chronic abdominal pain to differentiate between inflammatory bowel disease (IBD), other inflammatory gastrointestinal disorders, and functional gastrointestinal disorders. Methods . The study included 163 patients (median...

Introduction: Wilson disease (WD) may present from early childhood up to the eighth decade, presenting with variable hepatic and neuropsychiatric symptoms. Establishing the diagnosis is straightforward if the major clinical and laboratory features are present. However, clinical phenotypes are highly varied and early, proper diagnosis can be challe...

Ghrelin has been primarily shown to exhibit protective and therapeutic effect in the gut. Pretreatment with ghrelin inhibits the development of acute pancreatitis and accelerates pancreatic recovery in the course of this disease. In the stomach, ghrelin reduces gastric mucosal damage induced by ethanol, stress or alendronate, as well as accelerates...

Introduction Data on mesalazine (5-aminosalicylic acid; 5-ASA) use in cases of paediatric ulcerative colitis (UC) are limited. In this phase 1, randomised, open-label, multicentre study (NCT01130844), pharmacokinetic (PK) and safety profiles of 5-ASA and metabolite acetyl-5-ASA (Ac-5-ASA) were examined in youth with UC diagnoses after once-daily (Q...

Ghrelin has protective and therapeutic effects in the gut. The aim of present studies was to investigate the effect of treatment with ghrelin on the development of colitis evoked by dextran sodium sulfate (DSS). Methods. Studies have been performed on rats. Colitis was induced by adding 5% DSS to the drinking water for 5 days. During this period an...

Eosinophils contribute to the pathogenesis of inflammatory bowel disease (IBD) in the intestine. Eosinophilic cationic protein (ECP) is one of the most important eosinophilic specific mediators released during activation. The aim of the study was to evaluate the clinical value of serum ECP determination in children with active and inactive IBD and...

Unlabelled: Acute pancreatitis (AP) is becoming more frequent cause of hospitalization in children. There are no guidelines concerning optimal medical treatment in this condition, up to know. The aim of the study was the epidemiological and clinical assessment of AP in pediatric population. The evaluation of influence of administered pharmacothera...

Gastric lipase is one of the prepancreatic lipases found in some mammalian species and in humans. Our knowledge of the hormonal regulation of gastric lipase secretion in children and adolescents is still very limited. The aim of this study was to compare the activity of human gastric lipase (HGL) in gastric juice in healthy adolescents and in patie...

Background: Hospitalization of children is a highly stressful situation for their parents, related to the feeling of danger and uncertainty, which can affect family functioning. Aim of the study: The aim of this study was to assess the emotional reactions of parents to the hospitalization of their children, as well as to evaluate the differences in...

Eosinophilic disorders of the gastrointestinal tract are a heterogeneous group of rare and therefore rarely diagnosed chronic diseases occurring in both pediatric and adults. They represent a diverse clinical presentation, but their common feature is the presence of inflammatory infiltration of the intestinal wall with increased number of eosinophi...

Solitary rectal ulcer syndrome (SRUS) is a rare disorder of childhood, which usually presents with any of the manifestations of anorectal disease, bowel habit alteration and abdominal pain. It is commonly accepted that pathogenesis is associated with disturbances of defecation. We describe a 13-year-old boy with attention deficit hyperactivity diso...

Introduction: 13C-methacetin breath test (MBT) is a noninvasive test in the diagnosis of fatty liver. For the clinical definition of nonalcoholic fatty liver disease (NAFLD) a coexistence of abnormal liver ultrasound with an increase ALT concentration is assumed, but the "gold standard" in its diagnosis is still invasive liver biopsy. Aim of the st...

Introduction: Laryngopharyngeal reflux can damage the mucous membrane of the upper respiratory tract, among others of the Eustachian tube. Tubotympanal disorders are the basic etiologic factor of otitis media with effusion (OME), which is the main cause of the acquired hearing loss in children. Aim of the study: The aim of the study was to assess t...

Laryngopharyngeal reflux (LPR), which is also known as supraesophageal reflux (SER), is a retrograde movement of the stomach contents into the laryngopharynx, that is above the upper esophageal sphincter (UES). The pathophysiologic mechanisms of this phenomenon differ from the pathophysiologic mechanisms of typical gastroesophageal reflux (GER). In...

Introduction: One of the most common disorders in children is functional abdominal pain. There are a lot of underlying reasons which may cause this symptom. One of them is intolerance of carbohydrates. In recent years there has been a significant increase of fructose consumption, especially in the pediatric population. There is a suggestion that ex...

Overnutrition as well as undernutrition is a serious problem in hospitalized patients, especially in infants. Routine laboratory tests detecting disturbances in energy balance are not specific or accurate. The aim of this study was to evaluate adiponectin and leptin as markers of short-time energy malnutrition. Forty-five infants fed orally and par...

An adverse food reaction is defined as clinical symptoms occurring in children, adolescents or adults after ingestion of a food or chemical food additives. This reaction does not occur in healthy subjects. In certain individuals is a manifestation of the body hypersensitivity, i.e. qualitatively altered response to the consumed food. The disease sy...

Exclusive enteral nutrition (EEN) is an effective method of treatment in achieving remission in inflammatory bowel disease (IBD); however, its mechanism of action is still poorly understood. The objective of our study was to assess the influence of EEN on serum vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF-β1)...

The commensal microbiota of the gastrointestinal tract plays an important role in the pathogenesis of inflammatory bowel disease. We examined the horizontal structure of the fecal microbiota in the colon in adolescents with Crohn disease or ulcerative colitis and a control group. Fecal samples were collected in 3 fractions from patients with Crohn...

There are only a few studies on immune response to routine vaccinations in children with inflammatory bowel disease (IBD), despite a strong need for this kind of study. The aim of the study was to evaluate the immunogenicity of an inactivated hepatitis A vaccine (HAV) in IBD pediatric patients compared with healthy controls. This was an open, prosp...

Xenin is a newly discovered peptide in humans. The concentration of xenin in human plasma increases after meals and therefore this peptide is considered as a marker of satiety. The mechanism of xenin action in humans has not been thoroughly examined. MEDLINE database contains only few reports about the role of xenin in adults and none of them were...

Introduction: The presence of a foreign body in the gastrointestinal tract occurs mainly in little children and is usually the result of accidental ingestion. In most cases, a foreign body freely passes through the digestive tract, but it can lead to serious complications such as gastrointestinal obstruction, ulceration or perforation. Ingestion of...

Fibroblast growth factor 21 (FGF-21) is an atypical member of the FGF family. It act as an endocrine hormone which affects energy balance. In humans FGF-21 was correlated with obesity. The relationship of FGF-21 and starvation in the course of inflammatory bowel diseases (IBD) is unknown. Therefore the FGF-21 concentrations in children with IBD (n=...

Introduction: Electrogastrography (EGG) is a noninvasive diagnostic method recording gastric electrical activity by the use of skin electrodes. Discussion: The authors presented agreed consensus concerned with electrogastrography in the field of technique, normal values for children and adults, indications, interpretation of results, advantages and...

Introduction: Endoscopic Recurrent Cholangiopankreatography (ERCP) is rarely performed, highly specialized pediatric procedure. ERCP is carried out only in specialized centers cooperating with the specialists experienced in this procedure. Aim of the study was retrospective analysis involving 10-year period since 2000, when the ERCP at the Universi...

Introductions: Burns of the esophagus and stomach are caused mainly by accidental ingestion of corrosive substances. The extent of damage and the risk of early and late complications depend on the chemical and physical properties of the consumed substance, and the applied diagnostic and therapeutic procedures. Aim of the study: To describe clinical...

Effectiveness of enteral nutrition therapy is not only connected with improvement of the nutritional status of the patient, but also with its strong anti-inflammatory activity. Angiogenic growth factors play an important role in the early stage of inflammation. Vascular endothelial growth factor (VEGF) and transforming growth factor beta 1 (TGF-bet...

Hemophagocytic syndrome (HS) is a life-threatening condition of hyperinflammation. Main symptoms are: prolonged fever, cytopenia, hepatosplenomegaly, hemophagocytosis, hyperferritinemia, hypertriglyceridemia and hypofibrinogenemia. Primary genetic form and secondary HS associated with infections, malignancies or autoimmune disorders can be distingu...

Bacteria in the gut play a central role in the initiation and progress of inflammatory bowel disease (IBD). This study was prepared to elucidate the role in the inflammatory process of the bacterial species which are able to produce hydrogen peroxide, present in samples taken from colon lesions in adolescents with inflammatory bowel disease. Fifty...

To assess the mucosa-associated bacterial microflora and mucus layer in adolescents with inflammatory bowel disease (IBD). Sixty-one adolescents (mean age 15 years, SD+/-4.13) were included in the study. Intestinal biopsies from inflamed and non-inflamed mucosa of IBD patients and from controls with functional abdominal pain were cultured under aer...

Juvenile polyposis of infancy is one of the three forms of juvenile polyposis syndrom. It is the most severe form of juvenile polyposis syndrom with poor prognosis, affecting infants and children below 2 years of age. Onlya few cases of juvenile polyposis of infancy were reportedup to now. Clinical symptoms occur in first months of life, including...

The incidence of pediatric inflammatory bowel disease (IBD) in Western countries is on the rise. No prospective studies have been conducted on the epidemiology of pediatric IBD in Poland. The aim of the study was to define the characteristics of new pediatric IBD and assess the incidence of new IBD among children in Poland between 2002 and 2004. Pa...

Introduction: Gastrointestinal peptide YY (PYY) is a well-known satiety signal. Its role as an anti-inflammatory agent was recently disclosed. The aim of study was to measure the PYY plasma concentrations in infants fed with different formulas. Material and methods: The infants were divided into three age-matched groups: group I (13 healthy breast-...

Celiac disease is defined as a permanent gluten intolerance, which if untreated leads to malnutrition. The effect of that disease on the gut-brain axis remains unknown. This paper reports the level of plasma ghrelin, orexin A and B in a group of fifteen 8.6 ± 3.4-year-old children with untreated celiac disease and experimentally maintained on a glu...

Introduction: Data from the literature confirmed involvement of the nitrates (NO3) in the pathogenesis of inflammatory bowel disease (IBD). Nitrates are the stable metabolites of the nitric oxide (NO), and their serum concentrations reflect its endogenous production. It is known that there are increased NO3 concentration in serum and saliva of adul...

Introduction: Celiac disease occurs in approximately 34% of patients with autoimmune thyroid disease (AITD). Aim of study: estimating whether the prevalence of silent or previously not recognized celiac disease in children with AITD in Małopolska District justifies the screening for celiac disease in these patients. Material and methods: 109 patien...

Introduction: European Society for Paediatric Gastrology, Hepatology and Nutrition (ESPGHAN) endoscopy working group has reported many differences in pediatric endoscopy organization among participating countries. The training systems and specific guidelines are not unified. Aim of study: The aim of the study was to characterize the training system...

Although capsule endoscopy is a relatively noninvasive procedure that allows direct visualization of the entire small bowel, caries the risk of capsule retention in the gastrointestinal tract. Both symptomatic or asymptomatic cases, reported in the literature, were caused by abnormalities either in the intestine or abdomen. This report presents the...

Introduction: Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) are diseases with strong genetic background and significant influence of the environmental factors. The results of the latest research studies suggested the contribution of the Asp299Gly mutation of the Toll-like receptor-4 (TLR-4) gene to the...

Paper presents chosen diagnostical problems in abdominal disorders in children. Infant dyschezia was discussed as a functional disorder in infants. In older children symptoms like distention, and abdominal pain which were the results of gas overproduction were the main focus. Small bowel bacterial overgrowth and chronic intestinal pseudo-obstructio...

Introduction: Prevalence of coeliac disease (CD) in patients with diabetes mellitus type 1 (DM) has been estimated from 1.7 to 16.4% in different populations. Aim of study: The aim of the study was to evaluate the frequency of CD in patients with DM and to assess whether the coexistence of CD has an influence on physical development of the patient...

Gastroesophageal reflux disease (GERD) is frequent disorder of the gastro-intestinal tract. Although in adults GERD is regarded as a chronic disease, in children it is often considered as a transient disorder. To assess the natural history of GERD in infants and children. We enrolled 163 children (44% girls and 56% boys) with GERD diagnosed on the...

Data concerning prevalence rate of Helicobacter pylori gastritis in inflammatory bowel disease (IBD) patients is conflicting. We had studied the prevalence of Hp gastritis in newly diagnosed inflammatory bowel disease children before any pharmacological treatment was introduced. Ninety four consecutive children with inflammatory bowel diseased were...

Epidemiologic studies consistently demonstrate strong associations between gastro-esophageal reflux disease (GERD) and bronchial asthma also in children. A significant percentage of patients with GERD may experience extra-esophageal manifestations like cough or bronchspasm, which are typical symptoms of uncontrolled asthma. retrospective analysis o...

The work aimed at establishment of frequency of Helicobacter pylori (Hp) infection in children under 4 years of age. One hundred ninety-eight children (6 month to 4 year) were tested using urea breath test (UBT) with the non-radioactive isotope (13)C (50 mg of urea). The air was collected before and in the 20(th) and 30(th) minute after standard me...

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About 2/3 of constipated children present anal-rectal dyssynergy (ARD) with paradoxical contraction of the external anal sphincter (EAS) during defecation. The aim of our study was to answer the question whether additional treatment with biofeedback training (BF) is more effective than traditional treatment. MATERIALS, METHODS: We assessed chronica...

Introduction: Previous studies suggest that some probiotics are effective in shortening the duration of acute diarrhoea. In this trial the clinical efficacy of Trilac®, probiotic preparation containing 3 strains of lactic acid bacteria: L. acidophilus, B. bifidum, L. bulgaricus was assessed the treatment of acute diarrhoea in children. Objectives:...

It is known that ulcerative colitis (UC) patients have increased concentrations of interleukin 1β (IL-1β) and interleukin 1 receptor antagonist (IL-1ra). The aim of the present study was evaluation of serum IL-1β and IL-1ra and their correlations with clinical, endoscopic and histopathologic activity in UC children. Twenty children with active UC,...

Introduction: There is suggestion that serological markers could be of clinical value in differentiating Crohn's disease (CD) from ulcerative colitis (UC) and classification of cases with indeterminate colitis (IC). Objectives: The aim of the study was to evaluate diagnostic and clinical significance of autoantibodies testing in differential diagno...