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

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

Searching for genes influencing a complex disease: the case of coeliac disease.

Recently, a few genes have been reported to be causative in inflammatory diseases. Still, we are waiting for the vast majority to be discovered. New tools for genotyping and statistical analysis have been developed and emphasis has been put on study design. Coeliac disease (CD) is a disorder, where prolamins in dietary wheat gluten and related proteins from rye or barley are not tolerated. It is one of the most common chronic diseases in humans exceeding a population prevalence of 1%. In this article, we will summarise what is currently known about the genetics influencing CD with the emphasis on the non-HLA genetic component. We will discuss some difficulties when searching for susceptibility genes in disorders with complex inheritance patterns

Intestinal gluconeogenesis is downregulated in pediatric patients with celiac disease

Background: Untreated celiac disease (CD) patients have increased levels of blood glutamine and a lower duodenal expression of glutaminase (GLS). Intestinal gluconeogenesis (IGN) is a process through which glutamine is turned into glucose in the small intestine, for which GLS is crucial. Animal studies suggest impaired IGN may have long-term effects on metabolic control and be associated with the development of type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). The aim of this study was to thoroughly investigate IGN at the gene expression level in children with untreated celiac disease. Methods: Quantitative polymerase chain reaction (qPCR) was used to quantify the expression of 11 target genes related to IGN using the delta-delta Ct method with three reference genes (GUSB, IPO8, and YWHAZ) in duodenal biopsies collected from 84 children with untreated celiac disease and 58 disease controls. Results: Significantly lower expression of nine target genes involved in IGN was seen in duodenal biopsies from CD patients compared with controls: FBP1, G6PC, GLS, GPT1, PCK1, PPARGC1A, SLC2A2, SLC5A1, and SLC6A19. No significant difference in the expression was observed for G6PC3 or GOT1. Conclusions: Children with untreated celiac disease have lower expression of genes important for IGN. Further studies are warranted to disentangle whether this is a consequence of intestinal inflammation or due to an impaired metabolic pathway shared with other chronic metabolic diseases. Impaired IGN could be a mechanism behind the increased risk of NAFLD seen in CD patients

Decreased Risk of Parkinson's Disease After Rheumatoid Arthritis Diagnosis : A Nested Case-Control Study with Matched Cases and Controls

BACKGROUND: Rheumatoid arthritis (RA) and the genetic risk landscape of autoimmune disorders and Parkinson's disease overlap. Additionally, anti-inflammatory medications used to treat RA might influence PD risk.OBJECTIVE: To use a population-based approach to determine if there is an association between pre-occurring rheumatoid arthritis (RA) and later-life risk of Parkinson's disease (PD).METHODS: The study population was 3.6 million residents of Sweden, who were alive during part or all of the follow-up period; 1997-2016. We obtained diagnoses from the national patient registry and identified 30,032 PD patients, 8,256 of whom each was matched to ten controls based on birth year, sex, birth location, and time of follow-up. We determined the risk reduction for PD in individuals previously diagnosed with RA. We also determined if the time (in relation to the index year) of the RA diagnosis influenced PD risk and repeated the analysis in a sex-stratified setting.RESULTS: Individuals with a previous diagnosis of RA had a decreased risk of later developing PD by 30-50% compared to individuals without an RA diagnosis. This relationship was strongest in our conservative analysis, where the first PD diagnosis occurred close to the earliest PD symptoms (odds ratio 0.47 (CI 95% 0.28-0.75, p = 0.0006); with the greatest risk reduction in females (odds ratio 0.40 (CI 95% 0,19 -0.76, p = 0.002).DISCUSSION: Our findings provide evidence that individuals diagnosed with RA have a significantly lower risk of developing PD than the general population. Our data should be considered when developing or repurposing therapies aimed at modifying the course of PD

Pre-analytical (mis)handling of plasma investigated by 1H-NMR metabolomics

The pre-analytical handling of plasma, how it is drawn, processed, and stored, influences its composition. Samples in e.g. biobanks often lack this information and consequently important information about their quality. Especially metabolite concentrations are affected by pre-analytical handling making conclusions from metabolomics studies particularly sensitive to misinterpretations. The perturbed metabolite profile, however, also offers an attractive choice for assessing the pre-analytical history from the measured data. Here we show that it is possible using Orthogonal Projections to Latent Structures Discriminative Analysis to divide plasma NMR data into a multivariate \u27original sample space\u27 suitable for further less biased metabolomics analysis and an orthogonal \u27pre-analytical handling space\u27 describing the changes occurring from pre-analytical mishandling. Apart from confirming established pre-analytical effects on glucose metabolization and the consequent increase in e.g. lactate and pyruvate, the sample preparation protocol involved methanol precipitation which allowed the observation of reversible changes in short-chain fatty acid concentrations as a function of temperature

A family-based genome-wide association study of chronic rhinosinusitis with nasal polyps implicates several genes in the disease pathogenesis.

The pathogenesis of chronic rhinosinusitis with nasal polyps is largely unknown. Previous studies have given valuable information about genetic variants associated with this disease but much is still unexplained. Our goal was to identify genetic markers and genes associated with susceptibility to chronic rhinosinusitis with nasal polyps using a family-based genome-wide association study.427 patients (293 males and 134 females) with CRSwNP and 393 controls (175 males and 218 females) were recruited from several Swedish hospitals. SNP association values were generated using DFAM (implemented in PLINK) and Efficient Mixed Model Association eXpedited (EMMAX). Analyses of pathway enrichment, gene expression levels and expression quantitative trait loci were then performed in turn.None of the analysed SNPs reached genome wide significant association of 5.0 x 10-8. Pathway analyses using our top 1000 markers with the most significant association p-values resulted in 138 target genes. A comparison between our target genes and gene expression data from the NCBI Gene Expression Omnibus database showed significant overlap for 36 of these genes. Comparisons with data from expression quantitative trait loci showed the most skewed allelic distributions in cases with chronic rhinosinusitis with nasal polyps compared with controls for the genes HLCS, HLA-DRA, BICD2, VSIR and SLC5A1.Our study indicates that HLCS, HLA-DRA, BICD2, VSIR and SLC5A1 could be involved in the pathogenesis of chronic rhinosinusitis with nasal polyps. HLA-DRA has been associated with chronic rhinosinusitis with nasal polyps in previous studies and HLCS, BICD2, VSIR and SLC5A1 may be new targets for future research

Prediction and evaluation of the effect of pre-centrifugation sample management on the measurable untargeted LC-MS plasma metabolome

Optimal handling is the most important means to ensure adequate sample quality. We aimed to investigate whether pre-centrifugation delay time and temperature could be accurately predicted and to what extent variability induced by pre-centrifugation management can be adjusted for. We used untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics to predict and evaluate the influence of pre-centrifugation temperature and delayed time on plasma samples. Pre-centrifugation temperature (4, 25 and 37 degrees C; classification rate 87%) and time (5-210 min; Q(2) - 0.82) were accurately predicted using Random Forest (RF). Metabolites uniquely reflecting temperature and temperature-time interactions were discovered using a combination of RF and generalized linear models. Time-related metabolite profiles suggested a perturbed stability of the metabolome at all temperatures in the investigated time period (5-210 min), and the variation at 4 degrees C was observed in particular before 90 min. Fourteen and eight metabolites were selected and validated for accurate prediction of precentrifugation temperature (classification rate 94%) and delay time (Q(2) - 0.90), respectively. In summary, the metabolite profile was rapidly affected by pre-centrifugation delay at all temperatures and thus the pre-centrifugation delay should be as short as possible for metabolomics analysis. The metabolite panels provided accurate predictions of pre-centrifugation delay time and temperature in healthy individuals in a separate validation sample. Such predictions could potentially be useful for assessing legacy samples where relevant metadata is lacking. However, validation in larger populations and different phenotypes, including disease states, is needed

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