The frequency of IgE-dependent sensitization to food and airborne allergens in the population of children and adolescents of north-eastern Poland in 1998-2012 and its relation to the age of the studied patients.

Introduction: The long-term observation of the incidence of IgE-dependent sensitization to environmental allergens (food and airborne allergens) of a specific population plays an important role in epidemiological studies. Aim: Retrospective, comparative assessment of IgE-dependent sensitization to food and airborne allergens in the group of patients from the north-eastern region of Poland, in selected years (1998, 2003, 2008, 2012). Long-term assessment of the incidence of IgE-dependent sensitization depending on the age of the patients (1998-2012). Material and methods: A group of 6577 children and adolescents aged up to 18 years with a suspicion of an allergic process, diagnosed in 1998-2012. Skin prick tests (SPT) with selected food allergens and airborne allergens were used to evaluate the sensitization process of patients. Results: A significant increase in the percentage of patients sensitized was found, comparing 1998 vs. 2012: to at least one allergen (35.3% vs. 40.4%); only to food allergens (5.1% vs. 13.1%), and to at least one food allergen (10.5% vs. 20.1%). There were no significant changes in the percentage of children and adolescents sensitized to airborne allergens (22.7% vs. 20.3%). The percentage of sensitization to at least one allergen was lowest in 2-year-old children (30.2%), and highest in 15-year-old children (46.8%). The percentage of patients sensitized to airborne allergens increased statistically significantly with their age: 6.3% in infants, 43.7% in adolescents. Conclusions: During the 14-year-period of the study the authors observed an upward trend in the frequency of sensitization to food allergens. The frequency of sensitization to airborne allergens was similar at the beginning and the completion of the study.

The prevalence of IgE-dependent sensitizations to selected trophoallergens and airborne allergens in the population of children and adolescents of the north-eastern region of Poland.

INTRODUCTION: Good evidence has been provided over the last three to four decades that the prevalence of allergic diseases has been increasing in many developed countries worldwide. Recent data suggest that this increase may now be levelling off. AIM: Retrospective analysis of the prevalence of IgE-dependent sensitization and changes in selected environmental allergens in the population of children and adolescents in the north-eastern region of Poland in the years 1998-2012. MATERIAL AND METHODS: Skin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to the study in the years 1998-2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents. RESULTS: The retrospective study included children and adolescents aged up to 18 years with a suspicion of an allergic disease, referred to the regional tertiary medical centre for further diagnosis. A total of 6577 patients were studied, including 1556 (23.7%) in 1998, 1473 (22.4%) in 2003, 1690 (25.7%) in 2008, and 1858 (28.2%) in 2012. Sensitization to at least one allergen was observed in 39.0% of the examined children (regardless of the allergen type), of which 8.1% were sensitized to food allergens only, 23.9% to airborne allergens only, and 7.0% simultaneously to food and airborne allergens. During the 14-year study period, an increase was noted in the percentage of the sensitized children from 35.3% at baseline to 40.4% when the study was completed. The percentage of those sensitized to food allergens increased from 10.5% (1998) to 20.1% (2012). The percentage of children sensitized to airborne allergens remained unchanged at the level of 28.2% in 1998 and 27.2% in 2012. CONCLUSIONS: Measurement of skin prick test reactivity to different allergens is a useful and commonly used method in epidemiological studies for the assessment of allergic sensitization and changes in selected populations. The obtained results confirmed the need for systematic epidemiological research into allergic sensitization and allergic diseases among children and adolescents in Poland.

Atopic dermatitis. Interdisciplinary diagnostic and therapeutic recommendations of the Polish Dermatological Society, Polish Society of Allergology, Polish Pediatric Society and Polish Society of Family Medicine. Part II. Systemic treatment and new therapeutic methods.

The treatment goal in atopic dermatitis is eliminating clinical symptoms of the disease, preventing exacerbations and complications, as well as improving patients' quality of life. In cases of severe atopic dermatitis and lack of response it is recommended to introduce systemic therapy. Patients ofter require multi-specialist consultations, and occasionally hospitalization. It is not recommended to use acupuncture, acupressure, bioresonance, homeopathy, or Chinese herbs in the treatment of atopic dermatitis.

Atopic dermatitis. Interdisciplinary diagnostic and therapeutic recommendations of the Polish Dermatological Society, Polish Society of Allergology, Polish Pediatric Society and Polish Society of Family Medicine. Part I. Prophylaxis, topical treatment and phototherapy.

Atopic dermatitis is a chronic and recurrent inflammatory dermatosis with concomitant intensive pruritus, and is diagnosed both in children and adults. Atopic dermatitis-patients are predisposed to have bacterial, viral and fungal skin infections; they also suffer from an increased risk of developing food allergies (especially, at an infantile age), allergic rhinitis, or bronchial asthma (a so-called atopic march). Currently, an increasing atopic dermatitis incidence constitutes a serious medical problem that regards not only dermatology and allergology, but also paediatrics, and family medicine. The basis for atopic dermatitis treatment and prophylaxis is restoration of epidermal barrier functions by means of tailored emollients. Atopic dermatitis therapies should effectively eliminate clinical symptoms of the disease, prevent exacerbations as well as complications, and improve patients' quality of life.

IgE-dependent sensitization to tropho- and aeroallergens with regard to age, sex and birth season of children and adolescents living in the north-eastern region of Poland.

INTRODUCTION: A small number of studies concern trophoallergens and aeroallergens sensitization in the developmental age population in Poland. Only a few studies describe the role of selected factors determining the frequency and type of IgE-dependent sensitization in this population. AIM: To assess the rate of sensitization to chosen tropho- and aeroallergens in the group of sensitized patients living in the north-eastern region of Poland with regard to age, sex and birth season. MATERIAL AND METHODS: Skin prick testing (SPT) with selected food allergens (trophoallergens) and airborne allergens was used to evaluate the sensitization process of patients recruited to this study between 1998 and 2012. A positive result of sensitization was defined when the patient had at least one positive skin prick test with the allergen studied. The skin prick tests were done after written consent had been obtained from the parents. RESULTS: Significant results were as follows: sensitization was more common in boys (41.9%) than in girls (35.7%); the highest percentage of sensitized patients was observed in the group of children aged 13-18 years (45.0%) as compared to the group of children up to 3 years old (the lowest 33.1%). The highest percentage of sensitized patients was observed among children born during winter (41.3%), the lowest among children born in autumn (36.8%). CONCLUSIONS: The assessment of sensitization to chosen trophoallergens and airborne allergens should include the role of age, sex and birth season of the diagnosed patient.

Association of antioxidants and vitamin D level with inflammation in children with atopic dermatitis.

BACKGROUND: Changing the resources of vitamin D and antioxidant nutrients may affect the course of allergic diseases. The aim of the study was to investigate the association between CoQ10, vitamin D, retinol, and α-tocopherol serum levels and severity of atopic dermatitis (AD) in children. METHODS: Twenty-nine children with AD aged from 1 to 15 years were enrolled into the study. The severity of AD was categorized into mild or moderate (≤50 points in SCORAD - Scoring Atopic Dermatitis index) and severe (>50 SCORAD points). The control group was comprised of 22 children with negative history of allergy aged from 2 to 15. The serum measurements included vitamin D, retinol, α-tocopherol, CoQ10, C-reactive protein (CRP), complete blood count (CBC), and total immunoglobulin E (IgE). RESULTS: Low vitamin D concentration (<20 ng/ml) was observed mainly in patients with severe AD (77.8%), compared to children with mild or moderate AD (25%) or the control group (31.8%). Concentration of retinol was decreased significantly in patients with severe AD (median 1.32 µmol/l), compared to children with mild and moderate AD (median 1.66 µmol/l), but not to the control. Among inflammatory markers, only the group with severe AD demonstrated significantly elevated platelet count (PLT), red blood cell distribution width (RDW), and eosinophil count (EO). Retinol level correlated with PLT (R = -0.7; P = 0.003), white blood count (WBC) (R = -0.54; P = 0.01), total IgE (R = -0.51; P = 0.016), mean platelet volume (MPV) (R = 0.51; P = 0.02), and also with a disease severity index, SCORAD (R = -0.55; P = 0.007), whereas vitamin D level correlated only with MPV (R = 0.61; P = 0.003). No significant changes were found in tocopherol and CoQ10 levels between groups. CONCLUSIONS: Children with AD should be routinely tested for vitamin D deficiency, especially during disease exacerbation. Our results confirmed correlation of serum inflammatory markers with decreased concentration of vitamin A in children with AD. This finding, however, might be an effect of severe stage of disease and not only of inadequate intake of retinol in the diet.

The diagnosis and management of food allergies. Position paper of the Food Allergy Section the Polish Society of Allergology.

The paper concerns the current position of the Polish Society of Allergology Food Allergy Section on the diagnosis and management of food allergies. The aim of this position is to provide evidence-based recommendations on the diagnosis and management of patients with allergic hypersensitivity to foods. This position statement includes a systematic review of studies in three areas, namely, the epidemiology, diagnosis and management of food allergies. While taking into account the specific Polish setting, in this publication we also used the current European Academy of Allergy and Clinical Immunology (EAACI) position paper and other current position statements, including those of the United States National Institute of Allergy and Infectious Diseases (NIAID).

Relative cost-effectiveness of using an extensively hydrolyzed casein formula containing the probiotic Lactobacillus rhamnosus GG in managing infants with cow's milk allergy in Poland.

OBJECTIVE: To estimate the cost-effectiveness of using an extensively hydrolyzed casein formula (eHCF) containing the probiotic Lactobacillus rhamnosus GG (eHCF + LGG; Nutramigen LGG) as an initial treatment for cow's milk allergy compared with eHCF alone and amino acid formulas (AAF) in Poland from the perspective of the Polish National Health Fund (Narodowy Fundusz Zdrowia [NFZ]) and parents. METHODS: Decision modeling was used to estimate the probability of cow's milk allergic infants developing tolerance to cow's milk by 18 months. The model also estimated the cost to the NFZ and parents (Polish Zloty [PLN] at 2013-2014 prices) for managing infants over 18 months after starting one of the formulas as well as the relative cost-effectiveness of each of the formulas. RESULTS: The probability of developing tolerance to cow's milk by 18 months was higher among infants who were fed eHCF + LGG (0.82) compared with those fed eHCF alone (0.53) or an AAF (0.22). An infant who is initially managed with eHCF + LGG is expected to consume fewer health care resources than infants managed with the other formulas. Hence, the estimated total health care cost incurred by the NFZ for initially feeding infants with eHCF + LGG (PLN 5,693) was less than that of feeding infants with eHCF alone (PLN 7,749) or an AAF (PLN 24,333). However, the total cost incurred by parents for initially feeding infants with an AAF (PLN 815) was marginally less than that of feeding with eHCF + LGG (PLN 993), which was less than that of feeding with eHCF alone (PLN 1,226). CONCLUSION: Using eHCF + LGG instead of eHCF alone or an AAF for first-line management of newly diagnosed infants with cow's milk allergy affords a cost-effective use of NFZ-funded resources, since it improves outcome for less cost. Whether eHCF + LGG would be viewed as being cost-effective by parents is dependent on their willingness to pay an additional cost for additional tolerance acquisition to cow's milk.

EGFR and Bcl-2 in gastric mucosa of children infected with Helicobacter pylori.

UNLABELLED: The aim of the study was to evaluate the expression of EGFR and Bcl-2 proteins as inhibitory markers of apoptosis in surface epithelial cells and gland cells of antral gastric mucosa in children infected with Helicobacter pylori according to the severity and activity of antral gastritis and to assess the correlation between the number of cells expressing EGFR and the number of cells expressing Bcl-2 in H. pylori infected children. MATERIALS AND METHODS: The study included 44 children: 68.2% with chronic gastritis and positive IgG against H. pylori, and 31.8% with functional disorders of the gastrointestinal tract and with normal IgG against H. pylori. The evaluation of EGFR expression in gastric mucosa was performed immunohistochemically using monoclonal mouse anti-EGFR antibody. The polyclonal antibody was used to determine the expression of anti-Bcl-2. RESULTS: A significant increase in the number of cells expressing EGFR and Bcl-2 protein was found in the epithelial cells in severe as well as mild and moderate gastritis in the group of children infected with H. pylori. An increase in the number of cells expressing EGFR and Bcl-2 protein was also found in the epithelial cells in group I according to the activity of gastritis. There was a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children. CONCLUSION: Increased expression of EGFR and Bcl-2 proteins in the epithelial cells and a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children could suggest increased regeneration abilities of gastric mucosa.

Atopic dermatitis: current treatment guidelines. Statement of the experts of the Dermatological Section, Polish Society of Allergology, and the Allergology Section, Polish Society of Dermatology.

Atopic dermatitis (AD) is a condition frequently encountered in medical practices across the country. More than 60% of children with AD are at risk to develop allergic rhinitis or asthma (the atopic march). Patients with AD have a unique predisposition to colonization or infection by Staphylococcus aureus. Treatments for AD need to rapidly control symptoms of the disease, improve quality of life and prevent exacerbations. Given the chronic and relapsing nature of the disease, therapies need to encourage good compliance and be well tolerated.

Longitudinal observation of children with enhanced total serum IgE.

BACKGROUND: Long-term studies on the evolution of elevated total IgE (tIgE) concentration are in demand. OBJECTIVE: To investigate the prevalence of allergic diseases and influential factors in children with high tIgE levels during a 5-year period. METHODS: Children with high tIgE levels (>100 IU/mL) were study subjects. After the 5-year follow-up, an interview with the parents, clinical examination, and evaluation of tIgE and specific IgE (sIgE) to selected food and inhalant allergens were performed. RESULTS: The mean tIgE decreased significantly after 5 years in girls and boys regardless of the place of residence. Monosymptomatic patients accounted for most cases throughout the study, with the highest tIgE level at the beginning. After follow-up, the percentage of polysymptomatic patients increased. Their mean tIgE level was significantly higher than in the other groups. After follow-up, 11.7% of participants remained asymptomatic, and another 11.7% reported relief from symptoms. Allergy symptoms persisted in most children with normal tIgE levels. The 2-allergen sensitization was the most common through the study. Only patients sensitized to 4 allergens had unchanged levels of mean tIgE after follow-up and those with the highest mean tIgE level had a newly diagnosed sensitization to at least 1 allergen. A significant decrease of sIgE level was observed for food allergens. The values of sIgE to inhalant allergens even increased after the 5-year follow-up, despite decreased tIgE levels. CONCLUSION: In children with allergy and an elevated concentration of tIgE, the increasing or stable value of tIgE could be a useful parameter for the prediction of the development of polysymptomatic allergy.

High- and low-dose oral delayed-release mesalamine in children with mild-to-moderately active ulcerative colitis.

OBJECTIVE: The aim of the study was to assess the safety and efficacy of high- and low-dose oral, delayed-release mesalamine in a randomized, double-blind, active control study of children with mild-to-moderately active ulcerative colitis. METHODS: Patients ages 5 to 17 years, with a Pediatric Ulcerative Colitis Activity Index (PUCAI) score of ≥ 10 to ≤ 55 and a truncated Mayo Score of ≥ 1 for both rectal bleeding and stool frequency, were enrolled. They received body weight-dependent doses of oral, delayed-release mesalamine for 6 weeks in a low- (27-71 mg · g(-1) · day(-1)) or high-dose group (53-118 mg · g(-1) · day(-1)). The primary endpoint was treatment success, defined as the proportion of patients who achieved remission (PUCAI score <10) or partial response (PUCAI score ≥ 10 with a decrease from baseline by ≥ 20 points). Secondary endpoints included truncated Mayo Score and global assessment of change of disease activity. RESULTS: The modified intent-to-treat population included 81 of 83 patients enrolled. Treatment success by PUCAI was achieved by 23 of 41 (56%) and 22 of 40 (55%) patients in the mesalamine low- and high-dose groups, respectively (P = 0.924). Truncated Mayo Score (low-dose 30 [73%] and high-dose 28 [70%] patients) and other efficacy results did not differ between the groups. The type and severity of adverse events were consistent with those reported in previous studies of adults with ulcerative colitis and did not differ between groups. CONCLUSIONS: Both low- and high-dose oral, delayed-release mesalamine doses were equally effective as short-term treatment of mild-to-moderately active ulcerative colitis in children, without a specific benefit or risk to using either dose.

ß-casomorphin-7 alters µ-opioid receptor and dipeptidyl peptidase IV genes expression in children with atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease with heterogeneous clinical phenotypes reflecting genetic predisposition and exposure to environmental factors. Reactions to food may play a significant role especially in young children. Milk proteins are particularly strong allergens and are additional source of bioactive peptides including ß-casomorphin-7 (BCM7, Tyr-Pro-Phe-Pro-Gly-Pro-Ile). BCM7 exerts its influence on nervous, digestive, and immune functions via the µ-opioid receptor (MOR). Proline dipeptidyl peptidase IV (DPPIV; EC 3.4.14.5) appears to be the primary degrading enzyme of BCM7. Moreover, DPPIV is known to restrict activity of proinflammatory peptides. BCM7 is considered to modulate an immune response by affecting MOR and DPPIV genes expression. In this study, we determined the MOR and DPPIV genes expression in children diagnosed with a severe form of AD. 40 healthy children and 62 children diagnosed with severe AD (AD score ≥60) were included in the study. Peripheral blood mononuclear cells (PBMCs) from the studied subjects were incubated with the peptide extracts of raw and hydrolysed cow milk with defined ß-casein genotypes (A1A1, A2A2 and A1A2) and MOR and DPPIV genes expression was determined with real-time PCR. Incubation PBMCs with peptide extracts from cow milk caused an increase of the MOR gene expression (p<0.05; p<0.001) in AD children with a simultaneous decrease in the DPPIV gene expression (p<0.001). The obtained results supplement the knowledge on the BCM7 participation in AD etiology and provide an important diagnostic tool.

Hepatotoxicity caused by montelukast in a paediatric patient.

Montelukast is a selective and competitive cysteinyl leukotriene receptor antagonist (CystLTRA) which is increasingly used for the treatment of allergic asthma. Recently, hepatotoxicity has been reported with this drug in adult patients, but only one letter to the editor has reported a case of probable montelukast-induced hepatotoxicity in a child. We present a case of a 3.5-year-old boy, receiving treatment with montelukast, who developed hepatocellular injury. The exclusion of other causes of increased activity of aminotransferases (viral, metabolic, autoimmune), improvement after dechallenge, the morphological findings and previous reports of comparable cases support the diagnosis of montelukast-induced liver injury in this boy. Physicians should strictly analyse indications for this drug and be aware of potential drug-induced liver disease caused by this agent. Therefore, the periodical assessment of aminotransferases should be recommended during treatment with this leukotriene modifier.

Serum fetuin A concentration is elevated in children with non-alcoholic fatty liver disease.

PURPOSE: To assess the serum fetuin A concentration as a potential marker of subclinical atherosclerosis in obese children with NAFLD. MATERIAL/METHODS: A prospective analysis of 45 obese children initially diagnosed with liver pathology (elevated serum ALT activity and/or ultrasonographic liver brightness and/or hepatomegaly) was conducted. The diagnosis of NAFLD was established in the children with elevated serum ALT activity and liver steatosis on ultrasound examination. Viral hepatitis, autoimmune, metabolic liver diseases (Wilson disease, alpha-1-antitrypsin deficiency, cystic fibrosis) and drug and toxin-induced liver injury were excluded in all children. The degree of liver steatosis was graded according to Saverymuttu scale and the total liver lipids concentration was assessed using proton magnetic resonance spectroscopy ((1)H MRS). RESULTS: Serum fetuin A concentration was significantly higher in examined children compared to the control group (n=30) (p=0.00002). Higher serum fetuin A concentration was also observed in children with NAFLD (n=19) in comparison to the controls (p=0.000026). Additionally, higher BMI values, waist circumferences, ALT and GGT activity, intensity of liver steatosis on ultrasound and total concentration of lipids in the liver in (1)H MRS were found in children with NAFLD compared to the rest of the examined obese patients (n=26). There was not found any correlation of the investigated glycoprotein with any other assessed parameters both in children with NAFLD and obese children without NAFLD. CONCLUSION: Higher serum fetuin A concentration found in children with NAFLD compared to the control group support the hypothesis that atherosclerotic processes may develop faster in hepatopatic obese patients.

Supplementation with long chain polyunsaturated fatty acids in treatment of atopic dermatitis in children.

Some recent studies indicate that unsaturated fatty acids, components of cellular membranes and precursors of immunomodulators, play a significant role in the pathogenesis of some symptoms of atopic dermatitis. Since they cannot be synthesized by the human body, they must be provided with nutrition as the so called exogenous fatty acids: linoleic (a precursor of arachidonic acid) and α-linolenic acid (a precursor of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)). Their deficiency facilitates the development of some disorders, e.g. of the cardiovascular system or of the nervous system, or becomes the cause of intensification of ailments in their course e.g. pruritus and dryness in atopic dermatitis. Though clinical examinations to date confirm the efficacy of fatty acid supplementation in treatment of atopic dermatitis, their results are not explicit.

Respiratory response to proton pump inhibitor treatment in children with obstructive sleep apnea syndrome and gastroesophageal reflux disease.

OBJECTIVE: Evaluation of the respiratory response to proton pump inhibitors (PPI) in children with obstructive sleep apnea syndrome (OSAS) and gastroesophageal reflux disease (GERD). METHODS: Of 131 children diagnosed with OSAS (Apnea Hypopnea Index, AHI >1/h), 37 children (6.9 years; 28.24%) with GERD symptoms (>3 times/week) were included. Overnight polysomnography with 24h pH-metry was performed before and after 4-8 weeks of PPI treatment (omeprazole once a day, 1mg/kg). RESULTS: Of 37 children, 21 were diagnosed with acid GERD where pre- and post-treatment reflux indexes were 14.09±1.47 vs. 7.73±1.36; (p<0.001). The number of obstructive apneas and hypopneas decreased after PPI treatment, resulting in an AHI reduction from 13.08±3.11/h to 8.22±2.52/h; (p<0.01). Respiratory response to PPI ranged from complete resolution of OSA (three children with mild OSA; AHI<5/h; 10.31years; 14.29%) to lack of significant AHI change (six children with severe OSA; AHI>10/h; 3.62 years; 28.57%). Post-treatment AHI was predicted by pre-treatment reflux index (adjusted R(2)=0.487; p<0.001). CONCLUSIONS: Reduction of obstructive respiratory events following short-term PPI treatment in children with both GERD and OSAS may suggest a causal relationship between apnea and reflux in some children. Questionnaire screening for GERD in children with OSAS may be of benefit.

Low serum IgA and increased expression of CD23 on B lymphocytes in peripheral blood in children with regressive autism aged 3-6 years old.

INTRODUCTION: Immune system dysfunction is considered to be one of many medical disorders found in children with autism. The primary objective of the study was to assess if blood tests reflecting humoral immunity (IgA, IgG, IgM, IgE) are useful in identifying children with regressive autism. The secondary objective was to evaluate a part of the cellular arm of immunity (CD4/CD25 Tregs, CD4/CD23 cells) in those children. MATERIAL AND METHODS: Using a clinical case-control design, the systemic levels of immunoglobulins and lymphocyte subpopulations analysed by flow cytometry were compared in children aged 3-6 years old with a new diagnosis of regressive autism (n = 24; mean age: 4.25 ±1.70 years; male 23/24) and in sex- and age-matched healthy children (n = 24; aged 4.25 ±2.20 years; male 23/24). RESULTS: The humoral immunity profile, described by three binary variables, IgA < 0.97 g/l, IgE > 36 IU/ml, and IgG > 6.3 g/l, with a sensitivity of 79% and a specificity of 83% (p < 0.0001), was able to identify children with autism. The highest risk of autism diagnosis was associated with IgA < 0.97g/l (OR - 23.0; p < 0.001). A higher number of CD19/CD23 was found in children diagnosed with autism than in the control group (36.82 ±6.72% vs. 18.20 ±3.95%; p < 0.02). No correlation between the number of CD23-positive cells and serum IgE levels was observed. CONCLUSIONS: A subtle shift of serum immunoglobulins consisting of low-normal IgA and B cell activation expressed by an increase of CD23-positive cells may characterize children with regressive autism aged 3-6 years old.

A potential pathogenic role of oxalate in autism.

BACKGROUND: Although autistic spectrum disorders (ASD) are a strongly genetic condition certain metabolic disturbances may contribute to clinical features. Metabolism of oxalate in children with ASD has not yet been studied. AIM: The objective was to determine oxalate levels in plasma and urine in autistic children in relation to other urinary parameters. METHOD: In this cross-sectional study, plasma oxalate (using enzymatic method with oxalate oxidase) and spontaneous urinary calcium oxalate (CaOx) crystallization (based on the Bonn-Risk-Index, BRI) were determined in 36 children and adolescents with ASD (26 boys, 10 girls) aged 2-18 years and compared with 60 healthy non-autistic children matched by age, gender and anthropometric traits. RESULTS: Children with ASD demonstrated 3-fold greater plasma oxalate levels [5.60 (5th-95th percentile: 3.47-7.51)] compared with reference [(1.84 (5th-95th percentile: 0.50-4.70) µmol/L (p < 0.05)] and 2.5-fold greater urinary oxalate concentrations (p < 0.05). No differences between the two groups were found in urinary pH, citraturia, calciuria or adjusted CaOx crystallization rates based on BRI. Despite significant hyperoxaluria no evidence of kidney stone disease or lithogenic risk was observed in these individuals. CONCLUSIONS: Hyperoxalemia and hyperoxaluria may be involved in the pathogenesis of ASD in children. Whether this is a result of impaired renal excretion or an extensive intestinal absorption, or both, or whether Ox may cross the blood brain barrier and disturb CNS function in the autistic children remains unclear. This appears to be the first report of plasma and urinary oxalate in childhood autism.