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.

Validity of histology for the diagnosis of paediatric coeliac disease: a Swedish multicentre study.Montén, Caroline; Bjelkenkrantz, Kaj; Gudjonsdottir, Audur H; Browaldh, Lars; Arnell, Henrik; Naluai, Åsa Torinsson; Agardh, Daniel Link to publication Citation for published version (APA): Montén, C., Bjelkenkrantz, K., Gudjonsdottir, A. H., Browaldh, L., Arnell, H., Naluai, Å. T., & Agardh, D. (2016). Validity of histology for the diagnosis of paediatric coeliac disease: a Swedish multicentre study. Scandinavian Journal of Gastroenterology, 51(4), 427-433. DOI: 10.3109/00365521.2015.1101486 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal AbstractObjective: Histological evaluation of intestinal biopsies for the diagnosis of celiac disease can be challenging and compatible with risk for misdiagnosis. The aim was to evaluate the agreement of pathological diagnosis for celiac disease in children investigated at four major pediatric university hospitals in Sweden. Material 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 analyzed for tissue transglutaminase autoantibodies (tTGA) using radio ligand 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 celiac disease in 22 children of whom 7 children were tTGA positive. Conclusions:The variation between university hospitals on the pathological evaluation of biopsies may lead to misdiagnosis of celiac disease in pediatric 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.

BackgroundRisk 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.MethodsIntestinal 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.ResultsAll 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.ConclusionThe 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12881-015-0190-1) contains supplementary material, which is available to authorized users.

Background and ObjectivesGenome-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 MethodsThirty 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).ResultsA 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.ConclusionShared genetic factors involved in celiac disease, type 2 diabetes and anorexia nervosa suggest common underlying molecular pathways for these diseases.

Neurotensin (NT) is a gut hormone functioning proinflammatory through nuclear factor kappa B (NF-κB) and interleukin (IL)-8 secretion or anti-inflammatory through epidermal growth factor receptors. NT mRNA is down-regulated in duodenal biopsies of children with untreated coeliac disease. The aim of this study was to investigate if plasma pro-NT levels correlated with the degree of intestinal mucosal damage and tissue transglutaminase autoantibody (tTGA) levels in children with coeliac disease. Fasting plasma samples from 96 children with coeliac disease and 89 non-coeliac disease controls were analysed for NT precursor fragment pro-NT 1-117 by a chemiluminometric immunoassay. Pro-NT levels were compared with NT mRNA from duodenal biopsies, assessed previously with quantitative polymerase chain reaction (PCR). Illumina core exome arrays were used for human leucocyte antigen (HLA) typing and the Marsh criteria applied to score mucosal damage. Tissue TGA was measured by radio binding assay. A general linear model compared pro-NT levels with diagnosis of coeliac disease, Marsh score and HLA DQ haplotype. Spearman's rank test was used to compare pro-NT levels with tTGA, age and duodenal NT mRNA levels, respectively. Plasma pro-NT levels were elevated in children with coeliac disease (median 23 pmol/l higher, P = 0·003) and in those with severe intestinal mucosal damage (median 24 pmol/l higher for ≥ Marsh 3b versus not, P = 0·0004). Pro-NT levels correlated further with tTGA (r = 0·22, P = 0·002), but not with duodenal NTS mRNA levels (r = -0·12, P = 0·14). Pro-NT was not associated with any of the HLA risk-haplotypes. Elevated peripheral pro-NT levels reflect more severe forms of active coeliac disease, indicating a potential role of NT in intestinal inflammation.