Questionnaire showed that Swedish paediatric clinics complied well with the revised European guidelines for diagnosing coeliac disease.

AIM: In 2012, revised criteria for diagnosing childhood coeliac disease were published by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition and incorporated into the revised Swedish guidelines the same year. These made it possible, in certain cases, to diagnose coeliac disease without taking small bowel biopsies. This survey assessed the extent to which the new guidelines were implemented by Swedish paediatric clinics two years after their introduction. METHODS: In October 2014, we distributed a paper questionnaire including five questions on diagnostic routines to the 40 paediatric clinics in university or regional hospitals in Sweden that perform small bowel biopsies. RESULTS: All 36 (90%) clinics that responded used anti-tissue transglutaminase antibodies as the initial diagnostic test and some also used serological markers. Most clinics (81%) used endoscopy and took multiple duodenal biopsies, whereas only a few (19%) occasionally employed a suction capsule. Almost all clinics (86%) omitted taking small bowel biopsies in symptomatic children with repeatedly high coeliac serology and positive genotyping, thereby avoiding the need for invasive endoscopy under anaesthesia. CONCLUSION: The 2012 Swedish Paediatric Coeliac Disease Diagnostic Guidelines had been widely accepted and implemented in routine health care two years after their introduction.

Altered peripheral amino acid profile indicate a systemic impact of active celiac disease and a possible role of amino acids in disease pathogenesis.

BACKGROUND: We have previously performed a Genome Wide Association and linkage study that indicated a new disease triggering mechanism involving amino acid metabolism and nutrient sensing signaling pathways. OBJECTIVE: The aim of this study was to investigate if plasma amino acid levels differed among children with celiac disease compared with disease controls. MATERIALS AND METHODS: Fasting plasma samples from 141 children with celiac disease and 129 non-celiac disease controls, were analyzed for amino acid levels by liquid chromatography-tandem mass spectrometry (LC/MS). A general linear model using age and experimental effects as covariates was used to compare amino acid levels between children with a diagnosis of celiac disease and controls. RESULTS: Seven out of twenty-three analyzed amino acids were elevated in children with celiac disease compared with controls (tryptophan, taurine, glutamic acid, proline, ornithine, alanine and methionine). The significance of the individual amino acids do not survive multiple correction, however, multivariate analyses of the amino acid profile showed significantly altered amino acid levels in children with celiac disease overall and after correction for age, sex and experimental effects (p = 8.4 × 10-8). CONCLUSION: These findings support the idea that amino acids could influence systemic inflammation and play a possible role in disease pathogenesis.

Shared Genetic Factors Involved in Celiac Disease, Type 2 Diabetes and Anorexia Nervosa Suggest Common Molecular Pathways for Chronic Diseases.

BACKGROUND AND OBJECTIVES: Genome-wide association studies (GWAS) have identified several genetic regions involved in immune-regulatory mechanisms to be associated with celiac disease. Previous GWAS also revealed an over-representation of genes involved in type 2 diabetes and anorexia nervosa associated with celiac disease, suggesting involvement of common metabolic pathways for development of these chronic diseases. The aim of this study was to extend these previous analyses to study the gene expression in the gut from children with active celiac disease. MATERIAL AND METHODS: Thirty six target genes involved in type 2 diabetes and four genes associated with anorexia nervosa were investigated for gene expression in small intestinal biopsies from 144 children with celiac disease at median (range) age of 7.4 years (1.6-17.8) and from 154 disease controls at a median (range) age 11.4.years (1.4-18.3). RESULTS: A total of eleven of genes were differently expressed in celiac patients compared with disease controls of which CD36, CD38, FOXP1, SELL, PPARA, PPARG, AGT previously associated with type 2 diabetes and AKAP6, NTNG1 with anorexia nervosa remained significant after correction for multiple testing. CONCLUSION: Shared genetic factors involved in celiac disease, type 2 diabetes and anorexia nervosa suggest common underlying molecular pathways for these diseases.

Validity of histology for the diagnosis of paediatric coeliac disease: a Swedish multicentre study.

OBJECTIVE Histological evaluation of intestinal biopsies for the diagnosis of coeliac disease can be challenging and compatible with risk of misdiagnosis. The aim was to evaluate the agreement of pathological diagnosis for coeliac disease in children investigated at four major paediatric university hospitals in Sweden. MATERIALS AND METHODS Intestinal duodenal biopsies were collected from 402 children at median 9.7 years (1.4-18.3 years). A pathologist at each hospital performed the primary evaluation. A designated pathologist, blinded to the primary evaluation, performed a second Marsh classification of biopsies (M0 to M3c) taken from the bulb and duodenum separately. Kappa (κ) scores between first and second evaluation determined the agreement. Plasma samples were collected at the day of intestinal biopsy and analysed for tissue transglutaminase autoantibodies (tTGA) using radioligand-binding assays. RESULTS Marsh scores were concordant in 229/356 biopsies (64%, κ = 0.52, p < 0.0001). Among discordant results, 15/127 (12%) showed M0 in distal duodenum but ≥ M2 in the bulb, whereas the opposite was true for 8/127 (6%) of the biopsies. There were fewer collected duodenal biopsies, more missing bulb biopsies and missing CD3 staining among discordant evaluations. The second evaluation revealed a Marsh score compliant with coeliac disease in 22 children of whom seven children were tTGA positive. CONCLUSIONS The variation between university hospitals on the pathological evaluation of biopsies may lead to misdiagnosis of coeliac disease in paediatric patients. Access to clinical and endoscopic information as well as tTGA levels may be useful for the pathologist to complement the evaluation in dubious cases.

Genes involved in muscle contractility and nutrient signaling pathways within celiac disease risk loci show differential mRNA expression.

BACKGROUND: Risk gene variants for celiac disease, identified in genome-wide linkage and association studies, might influence molecular pathways important for disease development. The aim was to examine expression levels of potential risk genes close to these variants in the small intestine and peripheral blood and also to test if the non-coding variants affect nearby gene expression levels in children with celiac disease. METHODS: Intestinal biopsy and peripheral blood RNA was isolated from 167 children with celiac disease, 61 with potential celiac disease and 174 disease controls. Transcript levels for 88 target genes, selected from celiac disease risk loci, were analyzed in biopsies of a smaller sample subset by qPCR. Differentially expressed genes (3 from the pilot and 8 previously identified) were further validated in the larger sample collection (n = 402) of both tissues and correlated to nearby celiac disease risk variants. RESULTS: All genes were significantly down- or up-regulated in the intestinal mucosa of celiac disease children, NTS being most down-regulated (Fold change 3.6, p < 0.001). In contrast, PPP1R12B isoform C was up-regulated in the celiac disease mucosa (Fold change 1.9, p < 0.001). Allele specific expression of GLS (rs6741418, p = 0.009), INSR (rs7254060, p = 0.003) and NCALD (rs652008, p = 0.005) was also detected in the biopsies. Two genes (APPL2 and NCALD) were differentially expressed in peripheral blood but no allele specific expression was observed in this tissue. CONCLUSION: The differential expression of NTS and PPP1R12B indicate a potential role for smooth muscle contractility and cell proliferation in celiac disease, whereas other genes like GLS, NCALD and INSR suggests involvement of nutrient signaling and energy homeostasis in celiac disease pathogenesis. A disturbance in any of these pathways might contribute to development of childhood celiac disease.

A possible mechanism behind autoimmune disorders discovered by genome-wide linkage and association analysis in celiac disease.

Celiac disease is a common autoimmune disorder characterized by an intestinal inflammation triggered by gluten, a storage protein found in wheat, rye and barley. Similar to other autoimmune diseases such as type 1 diabetes, psoriasis and rheumatoid arthritis, celiac disease is the result of an immune response to self-antigens leading to tissue destruction and production of autoantibodies. Common diseases like celiac disease have a complex pattern of inheritance with inputs from both environmental as well as additive and non-additive genetic factors. In the past few years, Genome Wide Association Studies (GWAS) have been successful in finding genetic risk variants behind many common diseases and traits. To complement and add to the previous findings, we performed a GWAS including 206 trios from 97 nuclear Swedish and Norwegian families affected with celiac disease. By stratifying for HLA-DQ, we identified a new genome-wide significant risk locus covering the DUSP10 gene. To further investigate the associations from the GWAS we performed pathway analyses and two-locus interaction analyses. These analyses showed an over-representation of genes involved in type 2 diabetes and identified a set of candidate mechanisms and genes of which some were selected for mRNA expression analysis using small intestinal biopsies from 98 patients. Several genes were expressed differently in the small intestinal mucosa from patients with celiac autoimmunity compared to intestinal mucosa from control patients. From top-scoring regions we identified susceptibility genes in several categories: 1) polarity and epithelial cell functionality; 2) intestinal smooth muscle; 3) growth and energy homeostasis, including proline and glutamine metabolism; and finally 4) innate and adaptive immune system. These genes and pathways, including specific functions of DUSP10, together reveal a new potential biological mechanism that could influence the genesis of celiac disease, and possibly also other chronic disorders with an inflammatory component.

Antibodies against deamidated gliadin peptides and tissue transglutaminase for diagnosis of pediatric celiac disease.

OBJECTIVES: The aim of the present study was to evaluate diagnostic performance and actual costs in clinical practice of immumoglobulin (Ig)G/IgA deamidated gliadin peptide antibodies (DGP) as a complement to IgA antibodies against tissue transglutaminase (tTG) for the diagnosis of pediatric celiac disease (CD). METHODS: All of the consecutive patients younger than 18 years tested for tTG and/or DGP, who underwent duodenal biopsy because of suspected CD in Stockholm and Gothenburg, Sweden, from 2008 to 2010, were included. Medical records were reviewed. RESULTS: Of 537 children who underwent duodenal biopsy, 278 (52%) had CD. A total of 71 (13%) were younger than 2 years and 16 (4%) had IgA deficiency. Sensitivity and specificity for tTG were 94% and 86%, respectively. Corresponding values for DGP were 91% and 26%. Positive predictive values (PPV) were 88% for tTG and 51% for DGP. There were 148 children who were tTG-negative and DGP-positive, of which only 5% (8/148) had villous atrophy. Among children younger than 2 years with normal IgA, PPV was 96% (25/26) for tTG and 48% (24/50) for DGP. In 16 IgA-deficient children, 11 were DGP positive, of which 5 had CD (PPV 45%). Eight of 278 cases of CD would possibly have been missed without DGP. The cost of adding DGP and consequently more biopsies to be able to detect 8 extra cases of CD was [Euro sign]399,520 or [Euro sign]49,940 per case. CONCLUSIONS: For diagnosing CD, tTG is superior to DGP, even in children younger than 2 years. Combining tTG and DGP does not provide a better tradeoff between number of missed cases of CD, number of unnecessary duodenal biopsies, and cost than tTG alone.