A genetic perspective on coeliac disease. Trends Mol Med. 2010;16:537-550. [PMID: 20947431 DOI: 10.1016/j.molmed.2010.09.003]

Epigenome-wide Association Study Shows Differential DNA Methylation of MDC1, KLF9, and CUTA in Autoimmune Thyroid Disease

CONTEXT

Autoimmune thyroid disease (AITD) includes Graves disease (GD) and Hashimoto disease (HD), which often run in the same family. AITD etiology is incompletely understood: Genetic factors may account for up to 75% of phenotypic variance, whereas epigenetic effects (including DNA methylation [DNAm]) may contribute to the remaining variance (eg, why some individuals develop GD and others HD).

OBJECTIVE

This work aimed to identify differentially methylated positions (DMPs) and differentially methylated regions (DMRs) comparing GD to HD.

METHODS

Whole-blood DNAm was measured across the genome using the Infinium MethylationEPIC array in 32 Australian patients with GD and 30 with HD (discovery cohort) and 32 Danish patients with GD and 32 with HD (replication cohort). Linear mixed models were used to test for differences in quantile-normalized β values of DNAm between GD and HD and data were later meta-analyzed. Comb-p software was used to identify DMRs.

RESULTS

We identified epigenome-wide significant differences (P < 9E-8) and replicated (P < .05) 2 DMPs between GD and HD (cg06315208 within MDC1 and cg00049440 within KLF9). We identified and replicated a DMR within CUTA (5 CpGs at 6p21.32). We also identified 64 DMPs and 137 DMRs in the meta-analysis.

CONCLUSION

Our study reveals differences in DNAm between GD and HD, which may help explain why some people develop GD and others HD and provide a link to environmental risk factors. Additional research is needed to advance understanding of the role of DNAm in AITD and investigate its prognostic and therapeutic potential.

Microarray-based Analysis of Differential Gene Expression Profile in Rotenone-induced Parkinson's Disease Zebrafish Model

BACKGROUND & OBJECTIVES

Despite much clinical and laboratory research that has been performed to explore the mechanisms of Parkinson's disease (PD), its pathogenesis remains elusive to date. Therefore, this study aimed to identify possible regulators of neurodegeneration by performing microarray analysis of the zebrafish PD model's brain following rotenone exposure.

METHODS

A total of 36 adult zebrafish were divided into two groups: control (n = 17) and rotenonetreated (n = 19). Fish were treated with rotenone water (5 μg/L water) for 28 days and subjected to locomotor behavior analysis. Total RNA was extracted from the brain tissue after rotenone treatment. The cDNA synthesized was subjected to microarray analysis and subsequently validated by qPCR.

RESULTS

Administration of rotenone has significantly reduced locomotor activity in zebrafish (p < 0.05), dysregulated dopamine-related gene expression (dat, th1, and th2, p < 0.001), and reduced dopamine level in the brain (p < 0.001). In the rotenone-treated group, genes involved in cytotoxic T lymphocytes (gzm3, cd8a, p < 0.001) and T cell receptor signaling (themis, lck, p < 0.001) were upregulated significantly. Additionally, gene expression involved in microgliosis regulation (tyrobp, p < 0.001), cellular response to IL-1 (ccl34b4, il2rb, p < 0.05), and regulation of apoptotic process (dedd1, p < 0.001) were also upregulated significantly.

CONCLUSION

The mechanisms of T cell receptor signaling, microgliosis regulation, cellular response to IL-1, and apoptotic signaling pathways have potentially contributed to PD development in rotenonetreated zebrafish.

Early environmental risk factors and coeliac disease in adolescents: a population-based cohort study in Denmark

OBJECTIVES

Our aim was to investigate the association between early environmental factors and the development of coeliac disease (CeD) in adolescents, recruited from a cohort nested in the Danish National Birth Cohort (DNBC).

DESIGN

The study was designed as a prospective cohort study, nested in DNBC PARTICIPANTS: The Glutenfunen cohort comprises 1266 participants, nested in DNBC. All participants were screened for CeD, and in total, 28 cases of biopsy proven CeD were identified. Data about breastfeeding, timing of introduction to solid food in infancy, use of antibiotics, infections and symptoms were parentally reported prospectively at 6 months and 18 months, respectively. We estimated ORs and 95% CIs of CeD in adolescents using logistic regression analysis.

RESULTS

Viral croup reported at 18 months of age was associated with CeD in adolescents with an OR of 3.2 (95% CI: 1.2 to 8.7). Furthermore, otitis media also reported at 18 months of age was linked with CeD with an OR of 3.2 (95% CI: 1.5 to 7.3). We were not able to find any statistical associations between CeD and breastfeeding, frequency of infections, parentally reported use of antibiotic and timing of solid foods.

CONCLUSION

In this study, we present an overview of the relationship between early environmental factors and occurrence of CeD in adolescents. Our findings, despite limitations due to a limited number of cases of CeD, suggest a role of viral infections in the pathogenesis of CeD.

Pancreatic Cancer in Celiac Disease Patients-A Systematic Review and Meta-Analysis

Background: Celiac disease (CD) is an autoimmune enteropathy affecting approximately 1% of the population and is associated with an increased risk of enteropathy-associated T-cell lymphoma and small bowel adenocarcinoma, whereas the association between CD and other malignancies is unclear. Since pancreatic cancer (PC) remains one of the most lethal neoplasms and its incidence is increasing despite numerous ongoing research on diagnostic biomarkers and novel therapies, we aimed to investigate whether CD has an impact on the risk of PC. Material and Methods: We performed a systematic review of the literature published from January 2000 to March 2022 in two databases: Web of Science and Scopus and a meta-analysis of eligible studies. Results: Our search identified eight publications included in the systematic review. A total of five studies involving 47,941 patients, including 6399 CD patients with malignancies and 1231 PC cases were included in the meta-analysis and 221 cases of PC in CD patients with other cancers were recognized. The pooled OR for PC was 1.46 (95% CI 1.26−1.7) with significant heterogeneity (89.1%; p < 0.05), suggesting that CD patients with malignancies were at higher risk for PC. Conclusions: The association between CD and PC is uncertain. However, the results of the current meta-analysis may indicate an increased risk of PC in the group of patients with CD and other cancers. Further multicenter studies are warranted.

A statistical boosting framework for polygenic risk scores based on large-scale genotype data

Polygenic risk scores (PRS) evaluate the individual genetic liability to a certain trait and are expected to play an increasingly important role in clinical risk stratification. Most often, PRS are estimated based on summary statistics of univariate effects derived from genome-wide association studies. To improve the predictive performance of PRS, it is desirable to fit multivariable models directly on the genetic data. Due to the large and high-dimensional data, a direct application of existing methods is often not feasible and new efficient algorithms are required to overcome the computational burden regarding efficiency and memory demands. We develop an adapted component-wise L 2-boosting algorithm to fit genotype data from large cohort studies to continuous outcomes using linear base-learners for the genetic variants. Similar to the snpnet approach implementing lasso regression, the proposed snpboost approach iteratively works on smaller batches of variants. By restricting the set of possible base-learners in each boosting step to variants most correlated with the residuals from previous iterations, the computational efficiency can be substantially increased without losing prediction accuracy. Furthermore, for large-scale data based on various traits from the UK Biobank we show that our method yields competitive prediction accuracy and computational efficiency compared to the snpnet approach and further commonly used methods. Due to the modular structure of boosting, our framework can be further extended to construct PRS for different outcome data and effect types-we illustrate this for the prediction of binary traits.

Gluten Intake and Risk of Digestive System Cancers in 3 Large Prospective Cohort Studies

BACKGROUND & AIMS

In patients with celiac disease, gluten triggers an immune reaction that damages small intestinal villi and may increase long-term risk of gastrointestinal cancer. However, the health impacts of gluten in the general population are understudied. We aimed to examine the association between gluten intake and risk of digestive system cancers among individuals without celiac disease.

METHODS

We leveraged longitudinal data from 3 prospective cohorts, the Nurses' Health Study (1984-2018, 73,166 women aged 65.1 ± 10.8 years), Nurses' Health Study II (1991-2017, 90,423 women aged 49.1 ± 8.2 years), and Health Professionals Follow-Up Study (1986-2016, 42,617 men aged 64.8 ± 10.8 years). Using Cox proportional hazards regression, we estimated hazard ratios and 95% confidence intervals of digestive system cancers according to quintiles of gluten intake assessed from food frequency questionnaires.

RESULTS

During 4,801,513 person-years of follow-up, we documented 6231 incident digestive system cancer cases among 3 cohorts. After adjusting for a wide-range of risk factors, including body mass index, physical activity, diet quality, gluten intake was not associated with an increased risk of digestive system cancer, with a hazard ratio of 0.94 (95% confidence interval, 0.87-1.02) comparing the highest with the lowest quintile of gluten intake (P trend = .05). Similar null associations were found for individual digestive system cancers: oral cavity and oropharyngeal cancer, esophageal cancer, stomach cancer, small intestine cancer, colorectal cancer, pancreatic cancer, gallbladder cancer, and liver cancer.

CONCLUSIONS

Gluten intake was not associated with risk of digestive system cancers in adults without celiac disease. Restricting dietary gluten is unlikely to be beneficial to the prevention of digestive system cancers in the general population.

Unusually high titres of anti-tissue transglutaminase antibodies in monozygotic twins

Anti-tissue transglutaminase antibodies (anti-tTG) play a vital role in the screening process for coeliac disease (CD). Levels above 30 U/ml suggest a possible diagnosis of CD, prompting further investigation, usually by taking a duodenal biopsy. We report an unusual case of 39-year-old male twins, one presenting with iron deficiency anaemia and the other asymptomatic, with anti-tTG antibodies of >4,965.5 U/ml, an extraordinary level. A duodenal biopsy confirmed a diagnosis of CD and following the adoption of a gluten-free diet, anti-tTG levels were found to decrease back to normal levels. This case demonstrates how CD can cause significant biochemical and histological pathology, but present with mild or no symptoms.

Influence of Gluten-Free Diet on Gut Microbiota Composition in Patients with Coeliac Disease: A Systematic Review

The aim of this study was to assess the changes in microbiota composition during a gluten-free diet (GFD) in coeliac disease (CD) patients. The systematic search followed databases such as PUBMED (MEDLINE), SCOPUS, WEB OF SCIENCE and EMBASE. Out of 843 initially screened papers, a total number of 13 research papers were included. A total of 212 patients with CD on GFD, in comparison to 174 healthy individuals and 176 untreated patients with CD, were examined. Analysis of the microbial community based primarily on faecal samples and duodenal biopsies. Bifidobacterium was noticed to be less abundant in the study group than in both control groups, while the abundance of Bacteroides was more numerous in the group of CD patients on GFD. Staphylococcaceae prevailed in untreated CD patients. Despite the fact that the GFD was not able to fully restore commensal microorganism abundance, the treatment was associated with the greater abundance of selected beneficial bacteria and lower presence of pathogenic bacteria associated with worsening of CD symptoms.

The Nutritional Intervention of Resveratrol Can Effectively Alleviate the Intestinal Inflammation Associated With Celiac Disease Induced by Wheat Gluten

Background and Aims

Wheat gluten is a critical trigger for celiac disease, often causing inflammatory lesions and oxidative stress damage in the intestines of patients. In daily life, it is difficult for celiac disease patients to strictly avoid the dietary intake of gluten, which makes complementary preventive therapy particularly urgent. As such, we investigated the alleviating effects of resveratrol in vivo and in vitro models of celiac disease.

Methods

We established in vivo and in vitro models of gluten protein-induced celiac disease. The intervention effect of resveratrol was defined well based on relevant indicators of inflammation, immunity and oxidative stress, and its possible involvement in signaling pathways and genes were also identified.

Results

Resveratrol was effective in reducing intestinal oxidative stress and inflammatory damage induced by wheat gluten in both cell and mouse models for celiac disease. We identified correlations between the genes (Fgf15, Nr0b2, Aire and Ubd) and signaling pathways (PPAR, AMPK and FoxO) in which resveratrol performed critical roles.

Conclusions

Resveratrol contributed to regulate development of autoimmunity through up-regulation of Aire and Ubd genes and promote nutrient absorption in intestine through down-regulation of Fgf15 and Nr0b2 genes, as well as played a role in regulating complex response system of oxidative stress, inflammatory response and immune response in intestine by activating PPAR, AMPK and FoxO signaling pathways, thus effectively alleviating the intestinal symptoms of celiac disease.

Cesarean section is not associated with increased risk of celiac disease in the offspring: a meta-analysis

OBJECTIVE

Epidemiologic findings are inconsistent concerning the association between cesarean section (C-section) and celiac disease in offspring.

METHODS

We performed a systematic literature search of PubMed and Embase databases until July 2021. A meta-analysis was performed for each outcome in which a summary odds ratio (OR) was calculated while taking heterogeneity into account.

RESULTS

A total of 11 observational were identified for the literature review. We found that C-section was not associated with an increase in the risk of CD (OR = 1.03, 95% CI, 0.95-1.12; p = .501). In subgroup analyses, the association remained insignificant for both infants born after elective C-section (OR 1.05; 0.95-1.16; p = .329) and emergency C-section (OR 1.06; 1-1.13; p = .051).

CONCLUSIONS

Our results indicate that C-section is not associated with CD in offspring.

Celiac disease: From genetics to epigenetics

Celiac disease (CeD) is a multifactorial autoimmune disorder spread worldwide. The exposure to gluten, a protein found in cereals like wheat, barley and rye, is the main environmental factor involved in its pathogenesis. Even if the genetic predisposition represented by HLA-DQ2 or HLA-DQ8 haplotypes is widely recognised as mandatory for CeD development, it is not enough to explain the total predisposition for the disease. Furthermore, the onset of CeD comprehend a wide spectrum of symptoms, that often leads to a delay in CeD diagnosis. To overcome this deficiency and help detecting people with increased risk for CeD, also clarifying CeD traits linked to disease familiarity, different studies have tried to make light on other predisposing elements. These were in many cases genetic variants shared with other autoimmune diseases. Since inherited traits can be regulated by epigenetic modifications, also induced by environmental factors, the most recent studies focused on the potential involvement of epigenetics in CeD. Epigenetic factors can in fact modulate gene expression with many mechanisms, generating more or less stable changes in gene expression without affecting the DNA sequence. Here we analyze the different epigenetic modifications in CeD, in particular DNA methylation, histone modifications, non-coding RNAs and RNA methylation. Special attention is dedicated to the additional predispositions to CeD, the involvement of epigenetics in developing CeD complications, the pathogenic pathways modulated by epigenetic factors such as microRNAs and the potential use of epigenetic profiling as biomarker to discriminate different classes of patients.

Celiac disease poses significant risk in developing depression, anxiety, headache, epilepsy, panic disorder, dysthymia: A meta-analysis

Celiac disease (CD) primarily affects the small intestine. Previous studies have identified higher incidences of neuropsychiatric diseases among CD patients compared to non-CD controls. Genome-wide association studies have identified >60 non-human leukocyte antigen (HLA) genes associated with CD, where estimated 15% genes have role in neurological health. We carried out a systematic review and meta-analysis to estimate the potential risk conferred by CD in developing neuropsychiatric diseases. Literature search was performed till June 2019. Incidences of neuropsychiatric diseases were compared among CD and non-CD controls. Funnel plots and Egger's tests were used to evaluate publication bias and estimate study effects. Qualities of the included studies were estimated using Newcastle-Ottawa Scale. Quality of evidence was graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Odds of developing neuropsychiatric diseases among CD were evaluated by computing meta-odds ratio (Manten-Haenszel method) and Z test p-value using random and fixed effect models based on the degree of study heterogeneity. Thirteen non-randomized case-control studies were found eligible. Subjects suffering from CD were found to have significantly more risk to develop depression (p<1.00E-05; OR=1.60 [1.37-1.86]), anxiety (p=0.05; OR=1.41 [1.00-1.97]), headache (p<0.1.00E-05; OR=3.27 [2.46-4.34]), epilepsy (p<1.00E-04; OR=11.90 [3.78-37.43]), panic disorder (p<1.00E-04; OR=4.64 [2.22-9.70]), and dysthymia (p=2.00E-03; OR=5.27 [1.83-15.22]). CD is a major predisposing factor in developing array of common neuropsychiatric diseases. Shared biological processes and molecular networks could play a crucial role in disease co-occurrence. Detailed molecular evidences are needed to establish the cause-effect relationship between these diseases.

Gut Microbiota in Celiac Disease: Is There Any Role for Probiotics?

Celiac disease (CD) is an immune-mediated disorder initiated by the ingestion of gluten in genetically predisposed individuals. Recent data shows that changes in the gut microbiome composition and function are linked with chronic inflammatory diseases; this might also be the case for CD. The main aim of this manuscript is to discuss our present knowledge of the relationships between gut microbiota alterations and CD and to understand if there is any role for probiotics in CD therapy. PubMed was used to search for all of the studies published from November 2009 to November 2019 using key words such as “Celiac Disease” and “Microbiota” (306 articles), “Celiac Disease” and “Gastrointestinal Microbiome” (139), and “Probiotics” and “Celiac Disease” (97 articles). The search was limited to articles published in English that provided evidence-based data. Literature analysis showed that the gut microbiota has a well-established role in gluten metabolism, in modulating the immune response and in regulating the permeability of the intestinal barrier. Promising studies suggest a possible role of probiotics in treating and/or preventing CD. Nevertheless, human trials on the subject are still scarce and lack homogeneity. A possible role was documented for probiotics in improving CD-related symptoms, modulating the peripheral immune response and altering the fecal microbiota, although the results were not consistent in all of the studies. No evidence was found that probiotic administration might prevent CD onset. Knowledge of the role of intestinal bacteria in the development of CD opens new possibilities for its treatment through probiotic administration, even though further studies are needed to better clarify whether probiotics can help treat or prevent the disease and to define which probiotics to use, at what dose and for how long.

The Gut Microbiota in Celiac Disease and probiotics

Celiac disease (CeD) is an immune-mediated enteropathy, and unique in that the specific trigger is known: gluten. The current mainstay of therapy is a gluten-free diet (GFD). As novel therapies are being developed, complementary strategies are also being studied, such as modulation of the gut microbiome. The gut microbiota is involved in the initiation and perpetuation of intestinal inflammation in several chronic diseases. Intestinal dysbiosis has been reported in CeD patients, untreated or treated with GFD, compared to healthy subjects. Several studies have identified differential bacterial populations associated with CeD patients and healthy subjects. However, it is still not clear if intestinal dysbiosis is the cause or effect of CeD. Probiotics have also been considered as a strategy to modulate the gut microbiome to an anti-inflammatory state. However, there is a paucity of data to support their use in treating CeD. Further studies are needed with therapeutic microbial formulations combined with human trials on the use of probiotics to treat CeD by restoring the gut microbiome to an anti-inflammatory state.

Association study identified biologically relevant receptor genes with synergistic functions in celiac disease

Receptors are essential mediators of cellular physiology, which facilitate molecular and cellular cross-talk with the environment. Nearly 20% of the all known celiac disease (CD) genes are receptors by function. We hypothesized that novel biologically relevant susceptibility receptor genes act in synergy in CD pathogenesis. We attempted to identify novel receptor genes in CD by re-analyzing published Illumina Immunochip dense genotype data for a north Indian and  a European (Dutch) cohort. North Indian dataset was screened for 269 known receptor genes. Association statistics for SNPs were considered with minor allele frequency >15% and association P ≤ 0.005 to attend desired study power. Identified markers were tested for cross-ethnic replication in a European CD dataset. Markers were analyzed in-silico to explain their functional significance in CD. Six novel SNPs from MOG (rs29231, p = 1.21e-11), GABBR1 (rs3025643, p = 1.60e-7), OR2H2 (rs1233388, p = 0.0002), ABCF1 (rs9262119, p = 0.0005), ADRA1A (rs10102024, p = 0.003), and ACVR2A (rs7560426, p = 0.004) were identified in north Indians, of which three genes namely, GABBR1 (rs3025643, p = 5.38e-8), OR2H2 (rs1233388, p = 3.29e-5) and ABCF1 (rs9262119, p = 0.0002) were replicated in Dutch. Tissue specific functional annotation, potential epigenetic regulation, co-expression, protein-protein interaction and pathway enrichment analyses indicated differential expression and synergistic function of key genes that could alter cellular homeostasis, ubiquitination mediated phagosome pathway and cellular protein processing to contribute for CD. At present multiple therapeutic compounds/drugs are available targeting GABBR1 and ADRA1A, which could be tested for their effectiveness against CD in controlled drug trials.

Celiac disease in type 1 diabetes mellitus in the Kingdom of Saudi Arabia. Characterization and meta-analysis

Objectives:

To characterize and meta-analyze the pertinent studies concerning celiac disease (CD) among patients with type 1 diabetes mellitus (T1DM) in the Kingdom of Saudi Arabia.

Methods:

Data (from the relevant articles) were analyzed using both the Statistical Package for Social Sciences, version 20 (IBM Corp., Armonk, NY, USA) program and the comprehensive meta-analysis (CMA) program. This study was conducted between March and July 2018 at King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. Written ethical approval was not obtained because this study was a retrospective literature review and analysis.

Results:

The prevalence of seropositive-CD was 15.88% with high heterogeneity (I²=84.0), while the prevalence of biopsy-proven CD was 12% with high heterogeneity (I²=82.7). Anti-transglutaminase was used in 7 of the 8 studies; alone in 4; with endomysial antibodies in 2; and with antigliadin antibodies (AGA) in one. In the remaining study, antireticulin antibodies was used with AGA. The age of the involved patients ranged from 8 months to 50 years old.

Conclusion:

The prevalence of biopsy-proven CD among T1DM patients in Kingdom of Saudi Arabia (12.0%) was double the global prevalence (6.0%), and much higher than the normal Saudi population (1.4%). The female-to-male ratio (2:1) of CD patients in T1DM was the same as in the normal population in Kingdom of Saudi Arabia. No significant difference was detected between the reported serologically-proven rates and the reported biopsy-proven rates (p=0.093).

Recent advances in celiac disease and refractory celiac disease

Celiac disease (CeD), defined as gluten-induced enteropathy, is a frequent and largely underdiagnosed disease. Diagnosis relies on the detection of highly specific serum IgA anti-transglutaminase auto-antibodies and on the demonstration of duodenal villous atrophy. Treatment necessitates a strict gluten-free diet, which resolves symptoms and enables histological recovery. However, regular follow-up is necessary to assess mucosal healing, which emerges as an important prognostic factor. Recent work on CeD pathogenesis has highlighted how the cross-talk between gluten-specific CD4 + T cells and interleukin-15 can activate cytotoxic intraepithelial lymphocytes and trigger epithelial lesions. Moreover, acquisition by a subset of intraepithelial lymphocytes of somatic gain-of-function mutations in the JAK-STAT pathway was shown to be a decisive step in the progression toward lymphomas complicating CeD, thus opening new therapeutic perspectives for these rare but life-threatening complications.

Association Between Antibiotics in the First Year of Life and Celiac Disease

BACKGROUND & AIMS

The intestinal microbiota is believed to be involved in the pathogenesis of celiac disease, in addition to genetic variants and dietary gluten. The gut microbiota is strongly influenced by systemic antibiotics-especially in early life. We explored the association between exposure to a systemic antibiotic in the first year of life and risk of diagnosed celiac disease.

METHODS

We performed an observational nationwide register-based cohort study. We included all children born in Denmark from 1995 through 2012 or Norway from 2004 through 2012. Children born in Denmark were followed until May 8, 2015 (age at end of follow-up was 2.3-20.3 years) and children born in Norway were followed until December 31, 2013 (age at end of follow-up was 1-10 years). We collected medical information from more than 1.7 million children, including 3346 with a diagnosis of celiac disease. Exposure to systemic antibiotics was defined as a dispensed systemic antibiotic in the first year of life.

RESULTS

Exposure to systemic antibiotics in the first year of life was positively associated with diagnosed celiac disease in the Danish and Norwegian cohorts (pooled odds ratio 1.26, 95% confidence interval 1.16-1.36). We found a dose-dependent relation between an increasing number of dispensed antibiotics and the risk of celiac disease (pooled odds ratio for each additional dispensed antibiotic 1.08, 95% confidence interval 1.05-1.11). No specific type of antibiotic or age period within the first year of life was prominent. Adjustment for hospital admissions with an infectious disease in the first year of life did not change the estimates; adjustment for the number of maternally reported infections in the child in 2 large sub-cohorts decreased the association slightly (pooled odds ratio 1.18, 95% confidence interval 0.98-1.39).

CONCLUSION

In a nationwide study of children in Denmark and Norway, we found exposure to systemic antibiotics in the first year of life to be associated with a later diagnosis of celiac disease. These findings indicate that childhood exposure to systemic antibiotics could be a risk factor for celiac disease.

Celiac disease-on-chip: Modeling a multifactorial disease in vitro

Conventional model systems cannot fully recapitulate the multifactorial character of complex diseases like celiac disease (CeD), a common chronic intestinal disorder in which many different genetic risk factors interact with environmental factors such as dietary gluten. However, by combining recently developed human induced pluripotent stem cell (hiPSC) technology and organ-on-chip technology, in vitro intestine-on-chip systems can now be developed that integrate the genetic background of complex diseases, the different interacting cell types involved in disease pathology, and the modulating environmental factors such as gluten and the gut microbiome. The hiPSCs that are the basis of these systems can be generated from both diseased and healthy individuals, which means they can be stratified based on their load of genetic risk factors. A CeD-on-chip model system has great potential to improve our understanding of disease etiology and accelerate the development of novel treatments and preventive therapies in CeD and other complex diseases.

The relationship between 174 G/C and -572 G/C of IL-6 gene polymorphisms and susceptibility of celiac disease in the Iranian population

Introduction

Celiac disease (CD) is a chronic inflammatory intestinal disorder. Different immunological factors, including inflammatory cytokines, may play an important role in disease susceptibility.

Aim

To investigate the relationship between -174G/C and -572G/C gene polymorphisms and the serum level of interleukin 6 (IL-6) and susceptibility to CD in the Iranian population.

Material and methods

In this case-control study blood samples were collected of 105 patients with CD and 106 healthy subjects randomly in 2016 and evaluated by polymerase chain reaction-restriction fragments length polymorphism (PCR-RFLP) method. A sequence was also used to confirm the results of both polymorphisms. The IL-6 concentration was measured using ELISA.

Results

The results showed a significant relationship between polymorphism -572G in CD patients when compared with control subjects by genotype (p = 0.001) and alleles (p = 0.022), respectively. There was no significant relationship between polymorphism 174G and frequency of genotype, but an association of this polymorphism with the frequency of alleles (p = 0.034), age (p = 0.001), and body mass index (p = 0.003) was seen. The serum level of interleukin-6 was significantly associated only with rs1800796 (p < 0.001).

Conclusions

The results confirm previous studies in different parts of the world and indicate that IL-6 (572G/C) polymorphism may play a role in susceptibility to CD in the Iranian population.

Celiac disease in children

Celiac disease is a common immune-mediated disease, that may present, after gluten ingestion, with various and heterogeneous symptoms that can vary according to patients' age. The diagnostic screening test is serum anti-tissue transglutaminase IgA level. In doubt cases, antiendomysium IgA and the antideamidated gliadin peptides IgG could be useful to confirm the suspicion, before a biopsy will be perform. Since 2012, guidelines have made it possible to avoid the biopsy in symptomatic pediatric patients with high levels of antitransglutaminase IgA, positivity to antiendomysium IgA, and with HLA DQ2 or DQ8. In all other cases duodenal biopsy is still mandatory to confirm the diagnosis. The therapy of celiac disease is a lifelong gluten free diet. In children prognosis of celiac disease is good, without complications. Here we review and discuss the present literature about celiac disease in childhood.

ERAP1/ERAP2 and RUNX3 polymorphisms are not associated with ankylosing spondylitis susceptibility in Chinese Han

Previous studies show that endoplasmic reticulum‐associated aminopeptidase (ERAP1/ERAP2) and runt‐related transcription factor 3 (RUNX3) gene polymorphisms are associated with AS (ankylosing spondylitis) in European Caucasians. However, contradictory results were reported in different Asian populations. The purpose of this study was to determine whether eleven candidate single nucleotide polymorphisms (SNPs) in ERAP1/ERAP2 and six in RUNX3 genes confer susceptibility to AS with or without acute anterior uveitis (AAU) [AS⁺AAU⁺ or AS⁺AAU^–] in Chinese Han. Therefore, a case–control association study was performed in 882 AS⁺AAU^–, 884 AS⁺AAU⁺ and 1727 healthy controls. Genotyping was performed using the iPLEXGold genotyping assay. A meta‐analysis was performed to assess the association of polymorphisms of ERAP1 with AS susceptibility in Asian populations. No association was found between SNPs of ERAP1/ERAP2/RUNX3 and susceptibility of AS with or without AAU. A case–control study between patients with human leucocyte antigen HLA‐B27‐positive and healthy controls also failed to demonstrate an association of the tested SNP with AS with or without AAU. Moreover, a meta‐analysis showed that there was no association of rs30187, rs27037, rs27980, rs27434 and rs27582 in ERAP1 with AS in Chinese Han. Taken together, 17 SNPs in ERAP1/ERAP2 and RUNX3 genes did not confer disease susceptibility to AS in Chinese Han.

IL10 promoter haplotypes may contribute to altered cytokine expression and systemic inflammation in celiac disease

Celiac disease (CD) is an autoimmune/inflammatory condition triggered by dietary gluten intake in genetically predisposed individuals. Though associations with MHC class II HLA-DQ2 or -DQ8 are the primary and necessary genetic predisposition for CD, >97% of genetically predisposed individuals never develop CD. Cytokines were measured in the serum of CD patients and controls. Possible associations with IL10 promoter variants were investigated. Cytokine expression from PBMCs was monitored in response to gluten exposure, or CD3/TCR complex stimulation in the absence or presence of recombinant IL-10. Serum cytokines varied between patients with CD at the time of diagnosis, after dietary elimination of gluten, and healthy controls. Serum IL-17A reflected disease activity. Reduced IL-10 serum levels and altered IL-10 expression by PBMCs coincided with IL10 promoter haplotypes that encode for "low" IL-10 expression (ATA). Increased prevalence of ATA IL10 promoter haplotypes and subsequently reduced IL-10 expression may be an immunological cofactor in individuals genetically predisposed for the development of CD. Resulting cytokine imbalances may be utilized as disease biomarkers in CD.

Genetic susceptibility for celiac disease is highly prevalent in the Saudi population

BACKGROUND/AIM

To determine the frequency of celiac disease (CD)-predisposing human leukocyte antigen (HLA)-DQ genotypes in the Saudi population, where the prevalence of CD is 1.5% as recently reported in a mass screening study.

PATIENTS AND METHODS

In a cross-sectional population-based study, a total of 192 randomly selected healthy school children (97 females, mean age 10.5 ± 2.2 years, all negative for tissue transglutaminase-IgA) were typed for D QA1 and D QB1 genes by polymerase chain reaction sequence-specific oligonucleotide probes.

RESULTS

Of the 192 children, 52.7% carried the high-risk CD-associated HLA-DQ molecules: homozygous DQ2.5 ( 2.6%), DQ2.5/DQ2.2 ( 4.7%), heterozygous DQ2.5 ( 28.15%), homozygous DQ8 ( 4.2%), DQ8/DQ2.2 ( 3.6%), and double dose DQ2.2 ( 9.4%). Low-risk CD-associated HLA-DQ molecules (single dose DQ2.2 and heterozygous DQ8) constituted 3.6% and 9.4%, respectively. Among the very low-risk groups, individuals lacking alleles that contribute to DQ2/DQ8 variants (33.5%), 13.5% carried only one of the alleles of the high-risk HLA-DQ2.5 heterodimer called "half-heterodimer" (HLA-DQA1*05 in 12% and HLA-DQB1* 02 in 1.5%), and 20.8% lacked all the susceptible alleles (DQX.x). Gender distribution was not significantly different among the CD-risk groups.

CONCLUSION

We report one of the highest frequencies of CD-predisposing HLA-DQ genotypes among healthy general populations (52.7%) worldwide, which might partly explain the high prevalence of CD in the Saudi community.

Whole exome sequencing of a consanguineous family identifies the possible modifying effect of a globally rare AK5 allelic variant in celiac disease development among Saudi patients

Celiac disease (CD), a multi-factorial auto-inflammatory disease of the small intestine, is known to occur in both sporadic and familial forms. Together HLA and Non-HLA genes can explain up to 50% of CD’s heritability. In order to discover the missing heritability due to rare variants, we have exome sequenced a consanguineous Saudi family presenting CD in an autosomal recessive (AR) pattern. We have identified a rare homozygous insertion c.1683_1684insATT, in the conserved coding region of AK5 gene that showed classical AR model segregation in this family. Sequence validation of 200 chromosomes each of sporadic CD cases and controls, revealed that this extremely rare (EXac MAF 0.000008) mutation is highly penetrant among general Saudi populations (MAF is 0.62). Genotype and allelic distribution analysis have indicated that this AK5 (c.1683_1684insATT) mutation is negatively selected among patient groups and positively selected in the control group, in whom it may modify the risk against CD development [p<0.002]. Our observation gains additional support from computational analysis which predicted that Iso561 insertion shifts the existing H-bonds between 400^th and 556^th amino acid residues lying near the functional domain of adenylate kinase. This shuffling of amino acids and their H-bond interactions is likely to disturb the secondary structure orientation of the polypeptide and induces the gain-of-function in nucleoside phosphate kinase activity of AK5, which may eventually down-regulates the reactivity potential of CD4⁺ T-cells against gluten antigens. Our study underlines the need to have population-specific genome databases to avoid false leads and to identify true candidate causal genes for the familial form of celiac disease.

Celiac disease: From pathophysiology to treatment

Celiac disease, also known as "celiac sprue", is a chronic inflammatory disorder of the small intestine, produced by the ingestion of dietary gluten products in susceptible people. It is a multifactorial disease, including genetic and environmental factors. Environmental trigger is represented by gluten while the genetic predisposition has been identified in the major histocompatibility complex region. Celiac disease is not a rare disorder like previously thought, with a global prevalence around 1%. The reason of its under-recognition is mainly referable to the fact that about half of affected people do not have the classic gastrointestinal symptoms, but they present nonspecific manifestations of nutritional deficiency or have no symptoms at all. Here we review the most recent data concerning epidemiology, pathogenesis, clinical presentation, available diagnostic tests and therapeutic management of celiac disease.

No association between gluten sensitivity and amyotrophic lateral sclerosis

To examine evidence for a role of gluten sensitivity (GS) or celiac disease (CD) in ALS etiology, we included participants from a population-based case–control study in The Netherlands between January 2006 and December 2015. We compared levels and seroprevalence of IgA antibodies to tissue transglutaminase 6 (TG6) in 359 ALS patients and 359 controls, and to transglutaminase 2 (TG2) and endomysium (EMA) in 199 ALS patients and 199 controls. Questionnaire data on 1829 ALS patients and 3920 controls were examined for CD or gluten-free diets (GFD). Genetic correlation and HLA allele frequencies were analyzed using two genome-wide association studies: one on ALS (12,577 cases, 23,475 controls), and one on CD (4533 cases, 10,750 controls). We found one patient with TG6, TG2 and EMA antibodies who had typical ALS and no symptoms of GS. TG6 antibody concentrations and positivity, CD prevalence and adherence to a GFD were similar in patients and controls (p > 0.66) and in these patients disease progression was compatible with typical ALS. CD and ALS were not found to be genetically correlated (p > 0.37). CD-associated HLA allele frequencies were similar in patients and controls (p > 0.28). In conclusion, we found no serological evidence for involvement of gluten-related antibodies in ALS etiology nor did we observe an association between CD and ALS in medical history or genetic data, indicating that there is no evidence in our data for an association between the two diseases. Hence, a role for a GFD in the ALS treatment seems unlikely.

Runx3 in Immunity, Inflammation and Cancer

In this chapter we summarize the pros and cons of the notion that Runx3 is a major tumor suppressor gene (TSG). Inactivation of TSGs in normal cells provides a viability/growth advantage that contributes cell-autonomously to cancer. More than a decade ago it was suggested that RUNX3 is involved in gastric cancer development, a postulate extended later to other epithelial cancers portraying RUNX3 as a major TSG. However, evidence that Runx3 is not expressed in normal gastric and other epithelia has challenged the RUNX3-TSG paradigm. In contrast, RUNX3 is overexpressed in a significant fraction of tumor cells in various human epithelial cancers and its overexpression in pancreatic cancer cells promotes their migration, anchorage-independent growth and metastatic potential. Moreover, recent high-throughput quantitative genome-wide studies on thousands of human samples of various tumors and new investigations of the role of Runx3 in mouse cancer models have unequivocally demonstrated that RUNX3 is not a bona fide cell-autonomous TSG. Importantly, accumulating data demonstrated that RUNX3 functions in control of immunity and inflammation, thereby indirectly influencing epithelial tumor development.

Immunopathogenesis and therapeutic approaches in pediatric celiac disease

Celiac Disease is an autoimmune enteropathy with increasing incidence worldwide in both adults and children. It occurs as an inflammatory condition with destruction of the normal architecture of villi on consumption of gluten and related protein products found in wheat, barley and rye. However, the exact pathogenesis is not yet fully understood. A gluten-free diet remains the main modality of therapy to date. While some patients continue to have symptoms even on a gluten-free diet, adherence to this diet is also difficult, especially for the children. Hence, there is continued interest in novel methods of therapy and the current research focus is on the promising novel non-dietary modalities of treatment. Here, we critically reviewed the existing literature regarding the pathogenesis of celiac disease in children including the role of in-utero exposure leading to neonatal and infant sensitization and its application for the development of new therapeutic approaches for these patients.

Shared and unique common genetic determinants between pediatric and adult celiac disease

BACKGROUND

Based on age of presentation, celiac disease (CD) is categorised as pediatric CD and adult CD. It however remains unclear if these are genetically and/or phenotypically distinct disorders or just different spectrum of the same disease. We therefore explored the common genetic components underlying pediatric and adult CD in a well characterized north Indian cohort.

METHODS

A retrospective analysis of children (n = 531) and adult (n = 871) patients with CD between January 2001 and December 2010 was done. The database included basic demographic characteristics, clinical presentations, associated diseases and complications, if any. The genotype dataset was acquired for children (n = 217) and adult CD patients (n = 340) and controls (n = 736) using Immunochip. Association analysis was performed using logistic regression model to identify susceptibility genetic variants.

RESULTS

The predominant form of CD was classical CD in both pediatric and adult CD groups. There was remarkable similarity between pediatric and adult CD except for quantitative differences between the two groups such as female preponderance, non-classical presentation, co-occurrence of other autoimmune diseases being more common amongst adult CD. Notably, same HLA-DQ2 and -DQ8 haplotypes were established as the major risk factors in both types of CD. In addition, a few suggestively associated (p < 5 × 10(-4)) non-HLA markers were identified of which only ANK3 (rs4948256-A; rs10994257-T) was found to be shared and explain risk for ~45 % of CD patients with HLA allele.

DISCUSSION

Overall phenotypic similarity between pediatric and adult CD groups can be explained by contribution of same HLA risk alleles. Different non-HLA genes/loci with minor risk seem to play crucial role in disease onset and extra intestinal manifestation of CD. None of the non-HLA risk variants reached genome-wide significance, however most of them were shown to have functional implication to disease pathogenesis. Functional relevance of our findings needs to be investigated to address clinical heterogeneity of CD.

CONCLUSIONS

This present study is the first comparative study based on common genetic markers to suggest that CD in pediatric age group and in adults are the spectrum of the same disease with novel and shared genetic risk determinants. Follow-up fine mapping studies with larger study cohorts are warranted for further genetic investigation.

Current evidence on whether perinatal risk factors influence coeliac disease is circumstantial

Coeliac disease is triggered by an interplay of environmental and genetic factors and is one of the most prevalent autoimmune diseases in children, occurring in about 1% of Europeans. Over the last few decades, there has been a growing interest in the role of the perinatal environment in coeliac disease and this review discusses the growing body of literature on coeliac disease and perinatal risk factors.

CONCLUSION

There is still only circumstantial evidence that the perinatal environment influences coeliac disease development. Large-scale cohort studies and emerging scientific concepts, such as epigenetics, may help us establish the role of these environmental factors.

Meta-Analysis on Associations of RGS1 and IL12A Polymorphisms with Celiac Disease Risk

The pathogenesis of celiac disease (CD) has been related to polymorphisms in the regulator of G-protein signaling 1 (RGS1) and interleukin-12 A (IL12A) genes, but the existing findings are inconsistent. Our aim is to investigate the associations of two single-nucleotide polymorphisms (SNPs) (rs2816316 in RGS1 and rs17810546 in IL12A) with CD risk using meta-analysis. We searched PubMed and Web of Science on RGS1 rs2816316 and IL12A rs17810546 with CD risk. Odds ratio (OR) and 95% confidence interval (CI) of each SNP were estimated. All statistical analyses were performed on Stata 12.0. A total of seven studies were retrieved and analyzed. The available data indicated the minor allele C of rs2816316 was negatively associated with CD (C vs. A: OR = 0.77, 95% CI = 0.74-0.80), and a positive association was found for the minor allele G of rs17810546 (G vs. A: OR = 1.37, 95% CI = 1.31-1.43). The co-dominant model of genotype effect confirmed the significant associations between RGS1 rs2816316/IL12A rs17810546 and CD. No evidence of publication bias was observed. Our meta-analysis supports the associations of RGS1 and IL12A with CD and strongly calls for further studies to better understand the roles of RGS1 and IL12A in the pathogenesis of CD.

Coeliac Disease - New Pathophysiological Findings and Their Implications for Therapy

Coeliac disease (CD) is one of the most common diseases worldwide, resulting from a combination of environmental (gluten) and genetic (human leucocyte antigen (HLA) and non-HLA genes) factors. Depending on the geographical location, the prevalence of CD has been estimated to approximate 0.5-1%. The only treatment currently available for CD is a gluten-free diet (GFD) excluding gluten-containing cereals such as wheat, rye, and barley, and other foodstuffs with natural or added gluten. However, adherence rates and patient acceptance are often poor. Moreover, even in fully adherent patients, the diet may fail to induce clinical or histological improvement. Hence, it is unsurprising that studies show CD patients to be highly interested in non-dietary alternatives. The following review focuses on current pathophysiological concepts of CD, spotlighting those pathways which may serve as new possible, non-dietary therapeutic targets in the treatment of CD.

Intestinal Microbiota and Celiac Disease: Cause, Consequence or Co-Evolution?

It is widely recognized that the intestinal microbiota plays a role in the initiation and perpetuation of intestinal inflammation in numerous chronic conditions. Most studies report intestinal dysbiosis in celiac disease (CD) patients, untreated and treated with a gluten-free diet (GFD), compared to healthy controls. CD patients with gastrointestinal symptoms are also known to have a different microbiota compared to patients with dermatitis herpetiformis and controls, suggesting that the microbiota is involved in disease manifestation. Furthermore, a dysbiotic microbiota seems to be associated with persistent gastrointestinal symptoms in treated CD patients, suggesting its pathogenic implication in these particular cases. GFD per se influences gut microbiota composition, and thus constitutes an inevitable confounding factor in studies conducted in CD patients. To improve our understanding of whether intestinal dysbiosis is the cause or consequence of disease, prospective studies in healthy infants at family risk of CD are underway. These studies have revealed that the CD host genotype selects for the early colonizers of the infant’s gut, which together with environmental factors (e.g., breast-feeding, antibiotics, etc.) could influence the development of oral tolerance to gluten. Indeed, some CD genes and/or their altered expression play a role in bacterial colonization and sensing. In turn, intestinal dysbiosis could promote an abnormal response to gluten or other environmental CD-promoting factors (e.g., infections) in predisposed individuals. Here, we review the current knowledge of host-microbe interactions and how host genetics/epigenetics and environmental factors shape gut microbiota and may influence disease risk. We also summarize the current knowledge about the potential mechanisms of action of the intestinal microbiota and specific components that affect CD pathogenesis.

Additive and interaction effects at three amino acid positions in HLA-DQ and HLA-DR molecules drive type 1 diabetes risk

Variation in the human leukocyte antigen (HLA) genes accounts for one-half of the genetic risk in type 1 diabetes (T1D). Amino acid changes in the HLA-DR and HLA-DQ molecules mediate most of the risk, but extensive linkage disequilibrium complicates the localization of independent effects. Using 18,832 case-control samples, we localized the signal to 3 amino acid positions in HLA-DQ and HLA-DR. HLA-DQβ1 position 57 (previously known; P = 1 × 10(-1,355)) by itself explained 15.2% of the total phenotypic variance. Independent effects at HLA-DRβ1 positions 13 (P = 1 × 10(-721)) and 71 (P = 1 × 10(-95)) increased the proportion of variance explained to 26.9%. The three positions together explained 90% of the phenotypic variance in the HLA-DRB1-HLA-DQA1-HLA-DQB1 locus. Additionally, we observed significant interactions for 11 of 21 pairs of common HLA-DRB1-HLA-DQA1-HLA-DQB1 haplotypes (P = 1.6 × 10(-64)). HLA-DRβ1 positions 13 and 71 implicate the P4 pocket in the antigen-binding groove, thus pointing to another critical protein structure for T1D risk, in addition to the HLA-DQ P9 pocket.

Common polygenic variation in coeliac disease and confirmation of ZNF335 and NIFA as disease susceptibility loci

Coeliac disease (CD) is a chronic immune-mediated disease triggered by the ingestion of gluten. It has an estimated prevalence of approximately 1% in European populations. Specific HLA-DQA1 and HLA-DQB1 alleles are established coeliac susceptibility genes and are required for the presentation of gliadin to the immune system resulting in damage to the intestinal mucosa. In the largest association analysis of CD to date, 39 non-HLA risk loci were identified, 13 of which were new, in a sample of 12 014 individuals with CD and 12 228 controls using the Immunochip genotyping platform. Including the HLA, this brings the total number of known CD loci to 40. We have replicated this study in an independent Irish CD case–control population of 425 CD and 453 controls using the Immunochip platform. Using a binomial sign test, we show that the direction of the effects of previously described risk alleles were highly correlated with those reported in the Irish population, (P=2.2 × 10⁻¹⁶). Using the Polygene Risk Score (PRS) approach, we estimated that up to 35% of the genetic variance could be explained by loci present on the Immunochip (P=9 × 10⁻⁷⁵). When this is limited to non-HLA loci, we explain a maximum of 4.5% of the genetic variance (P=3.6 × 10⁻¹⁸). Finally, we performed a meta-analysis of our data with the previous reports, identifying two further loci harbouring the ZNF335 and NIFA genes which now exceed genome-wide significance, taking the total number of CD susceptibility loci to 42.

Assessing of Celiac Disease and Nonceliac Gluten Sensitivity

The publication of papers on the topic of gluten related disorders has substantially increased over the last few years. This has motivated healthcare professionals to pay attention not only to celiac disease and wheat allergy but also to a condition termed nonceliac gluten sensitivity (NCGS). Until now this condition has been diagnosed clinically on the basis of exclusion criteria and clinical response to gluten withdrawal. In addition, recent research in this field has shown that other food components distinct from gluten are implicated in NCGS cases, thereby changing our general understanding of NCGS diagnosis in either individuals on gluten containing diets or those already following a gluten-free diet with no proper diagnostic work-up of celiac disease. With this in mind, the assessment of NCGS will require extensive knowledge of celiac disease manifestations and the laboratory tests commonly performed during diagnosis of celiac disease.

Runx3 at the interface of immunity, inflammation and cancer

Inactivation of tumor suppressor genes (TSG) in normal cells provides a viability/growth advantage that contributes cell-autonomously to cancer. More than a decade ago claims arose that the RUNX3 member of the RUNX transcription factor family is a major TSG inactivated in gastric cancer, a postulate extended later to other cancers. However, evidence that Runx3 is not expressed in normal gastric and other epithelia has challenged the RUNX3-TSG paradigm. Here we critically re-appraise this paradigm in light of recent high-throughput, quantitative genome-wide studies on thousands of human samples of various tumors and new investigations of the role of Runx3 in mouse cancer models. Collectively, these studies unequivocally demonstrate that RUNX3 is not a bona fide cell-autonomous TSG. Accordingly, RUNX3 is not recognized as a TSG and is not included among the 2000 cancer genes listed in the "Cancer Gene Census" or "Network for Cancer Genes" repositories. In contrast, RUNX3 does play important functions in immunity and inflammation and may thereby indirectly influence epithelial tumor development.

Effect of one year of a gluten-free diet on the clinical evolution of irritable bowel syndrome plus fibromyalgia in patients with associated lymphocytic enteritis: a case-control study

Introduction

Irritable bowel syndrome (IBS), lymphocytic enteritis (LE) and fibromyalgia syndrome (FMS) are three common disorders. Since a gluten-free diet (GFD) has been shown to be helpful in LE, we aimed to assess its effect in a series of LE patients also diagnosed with IBS and FMS.

Methods

The study sample comprised 97 IBS plus FMS adult females, of whom 58 had LE (Marsh stage 1), and 39 had a normal duodenal biopsy (Marsh stage 0). All patients fulfilled the Rome III and American College of Rheumatology 1990 criteria. All participants followed a GFD, the effectiveness of which was assessed by changes in the results of several tests, including those of the Fibromyalgia Impact Questionnaire (FIQ), the Health Assessment Questionnaire (HAQ), tender points (TPs), the Short Form Health Survey (SF-36), and the Visual Analogue Scales (VAS) for gastrointestinal complaints, pain and fatigue.

Results

At baseline, all patients had a poor quality of life (QoL) and high VAS scores. After one year on a GFD, all outcome measures were somewhat better in the Marsh stage 1 group, with a mean decrease of 26 to 29% in the TPs, FIQ, HAQ and VAS scales, accompanied by an increase of 27% in the SF-36 physical and mental component scores. However, in the IBS plus FMS/Marsh stage 0 group, the GFD had almost no effect.

Conclusions

This pilot study shows that a GFD in the LE-related IBS/FMS subgroup of patients can produce a slight but significant improvement in all symptoms. Our findings suggest that further studies of this subject are warranted.

Breast-feeding duration and gluten introduction among mothers with celiac disease

OBJECTIVES

Both breast-feeding duration and age at gluten introduction have been implicated in the pathogenesis of celiac disease (CD). We hypothesized that parental CD affects the feeding pattern of the offspring, mediated by parental health awareness increasing adherence to infant feeding guidelines.

METHODS

Prospectively collected infant feeding data were obtained through the All Babies in Southeast Sweden study. Information regarding infant feeding was available in 9414 children. Twenty-two mothers had a history of biopsy-verified CD before delivery of a child in the study, and 9392 mothers had no diagnosis of CD before birth and thus constituted the unexposed or control population. Cox regression was used to compare the risk of early weaning and gluten introduction according to parental CD status, and logistic regression to assess whether mothers with CD were more likely to breast-feed their children at gluten introduction.

RESULTS

Some 63% of children were breast-fed for at least 9 months. We found no association between maternal CD and early weaning (adjusted hazard ratio [HR] 1.0, 95% confidence interval [CI] 0.6-1.7), or between paternal CD and early weaning (HR 0.5, 95% CI 0.1-1.9). Sixty percent of children were introduced to gluten in months 5 and 6. Maternal CD was not associated with age at gluten introduction (adjusted HR 0.8, 95% CI 0.6-1.3). There was no statistically significant association between maternal CD and breast-feeding at the time of gluten introduction (odds ratio 1.4, 95% CI 0.4-4.7).

CONCLUSIONS

Feeding patterns do not seem to vary between offspring and mothers with CD and those without.

Epitope mapping of the N-terminal portion of tissue transglutaminase protein antigen to identify linear epitopes in celiac disease

Celiac disease (CD) is an autoimmune mediated disease with complex and multifactorial etiology. Gluten intake triggers a composite immune response involving T-cells and B-cells and leading to the secretion of autoantibodies if a genetic predisposition is present. Untreated CD patients show high levels of circulating autoantibodies directed to different auto-antigens present in the intestinal mucosa. The most important auto-antigen is the endomysial enzyme tissue transglutaminase (tTG). Both IgA and IgG antibody isotypes to tTG are known, but only the IgA antibodies demonstrate the highest disease specificity and thus are considered disease biomarkers. Because the pathogenicity and exact tTG binding properties of these autoantibodies are still unclear, the characterization of tTG antigenic domains is a crucial step in understanding CD onset and the autoimmune pathogenesis. Overlapping peptide libraries can be used for epitope mapping of selected protein portions to determine antigenic fragments contributing to the immunological activity and possibly develop innovative peptide-based tools with high specificity and sensitivity for CD. We performed an epitope mapping study to characterize putative linear auto-antigenic epitopes present in the tTG N-terminal portion (1-230). A library of 23 overlapping peptides spanning tTG(1-230) was generated by Fmoc/tBu solid-phase peptide synthesis and screened by immunoenzymatic assays employing patients' sera. The results indicate that four synthetic peptides, that is, Ac-tTG(1-15)-NH2 , Ac-tTG(41-55)-NH2 , Ac-tTG(51-65)-NH2 , and Ac-tTG(151-165)-NH2 , are recognized by IgA autoantibodies circulating in CD patients' sera. These results offer important insight on the nature of the antigen-antibody interaction.

Serological assessment for celiac disease in IgA deficient adults

PURPOSE

Selective immunoglobulin A deficiency is the most common primary immunodeficiency disorder that is strongly overrepresented among patients with celiac disease (CD). IgG antibodies against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) serve as serological markers for CD in IgA deficient individuals, although the diagnostic value remains uncertain. The aim of this study was to investigate the prevalence of these markers in a large cohort of IgA deficient adults with confirmed or suspected CD and relate the findings to gluten free diet.

METHODS

Sera from 488,156 individuals were screened for CD in seven Swedish clinical immunology laboratories between 1998 and 2012. In total, 356 out of 1,414 identified IgA deficient adults agreed to participate in this study and were resampled. Forty-seven IgA deficient blood donors served as controls. Analyses of IgG antibodies against tTG and DGP as well as HLA typing were performed and a questionnaire was used to investigate adherence to gluten free diet. Available biopsy results were collected.

RESULTS

Out of the 356 IgA deficient resampled adults, 67 (18.8%) were positive for IgG anti-tTG and 79 (22.2%) for IgG anti-DGP, 54 had biopsy confirmed CD. Among the 47 IgA deficient blood donors, 4 (9%) were positive for IgG anti-tTG and 8 (17%) for anti-DGP. Four were diagnosed with biopsy verified CD, however, 2 of the patients were negative for all markers. Sixty-eight of 69 individuals with positive IgG anti-tTG were HLA-DQ2/DQ8 positive whereas 7 (18.9%) of the 37 individuals positive for IgG anti-DGP alone were not.

CONCLUSIONS

IgG anti-tTG seems to be a more reliable marker for CD in IgA deficient adults whereas the diagnostic specificity of anti-DGP appears to be lower. High levels of IgG antibodies against tTG and DGP were frequently found in IgA deficient adults despite adhering to gluten free diet.

Ischaemic heart disease in first-degree relatives to coeliac patients

OBJECTIVE

Coeliac disease (CD) has been linked to an increased risk of ischaemic heart disease (IHD). We examined the risk of IHD in first-degree relatives and spouses to coeliac patients to ascertain the genetic contribution to IHD excess risk.

STUDY DESIGN AND SETTING

Coeliac disease was defined as having a biopsy-verified villous atrophy (Marsh grade 3) in 1969-2008 (n = 29,096). Coeliac patients were matched to 144,522 controls. Through Swedish registers, we identified all first-degree relatives and spouses to coeliac patients and their controls, in total 87,622 unique coeliac relatives and 432,655 unique control relatives. Our main outcome measure was IHD defined according to relevant international classification of disease codes in the Swedish Inpatient Registry or in the Cause of Death Registry. Hazard ratios (HR) and confidence intervals (CI) were estimated through Cox regression adjusted for sex, age-group and calendar year at study entry of the relative.

RESULT

During a median follow-up of 10·8 years, 2880 coeliac relatives and 13,817 control relatives experienced IHD. First-degree relatives of coeliac patients were at increased risk of IHD (HR = 1·05; 95% CI = 1·00-1·09, P-value = 0·04), while spouses were at no increased risk (HR = 0·99; 95% CI = 0·87-1·12). The excess risk of IHD in coeliac first-degree relatives aged 40-59 years was 70/100,000 person-years.

CONCLUSION

First-degree relatives to coeliac patients seem to be at an increased risk of IHD but the excess risk is so small that it has little clinical relevance.

A metabolomic perspective on coeliac disease

Metabolomics is an "omic" science that is now emerging with the purpose of elaborating a comprehensive analysis of the metabolome, which is the complete set of metabolites (i.e., small molecules intermediates) in an organism, tissue, cell, or biofluid. In the past decade, metabolomics has already proved to be useful for the characterization of several pathological conditions and offers promises as a clinical tool. A metabolomics investigation of coeliac disease (CD) revealed that a metabolic fingerprint for CD can be defined, which accounts for three different but complementary components: malabsorption, energy metabolism, and alterations in gut microflora and/or intestinal permeability. In this review, we will discuss the major advancements in metabolomics of CD, in particular with respect to the role of gut microbiome and energy metabolism.

Measles contributes to rheumatoid arthritis: evidence from pathway and network analyses of genome-wide association studies

Growing evidence from epidemiological studies indicates the association between rheumatoid arthritis (RA) and measles. However, the exact mechanism for this association is still unclear now. We consider that the strong association between both diseases may be caused by shared genetic pathways. We performed a pathway analysis of large-scale RA genome-wide association studies (GWAS) dataset with 5,539 cases and 20,169 controls of European descent. Meanwhile, we evaluated our findings using previously identified RA loci, protein-protein interaction network and previous results from pathway analysis of RA and other autoimmune diseases GWAS. We confirmed four pathways including Cytokine-cytokine receptor interaction, Jak-STAT signaling, T cell receptor signaling and Cell adhesion molecules. Meanwhile, we highlighted for the first time the involvement of Measles and Intestinal immune network for IgA production pathways in RA. Our results may explain the strong association between RA and measles, which may be caused by the shared genetic pathway. We believe that our results will be helpful for future genetic studies in RA pathogenesis and may significantly assist in the development of therapeutic strategies.

Duodenal microbiota composition and mucosal homeostasis in pediatric celiac disease

BACKGROUND

Celiac disease (CD) is an autoimmune disorder of the small intestine which is triggered by dietary gluten in genetically predisposed (HLA-DQ2/DQ8 positive) individuals. Only a fraction of HLA-DQ2/DQ8 positive individuals develop CD indicating that other factors have a role in the disorder. Several studies have addressed intestinal microbiota aberrancies in pediatric CD, but the results are inconsistent. Previously, we demonstrated that pediatric CD patients have lower duodenal expression of TLR2 and higher expression of TLR9 as compared to healthy controls (HC) indicating that microbiota may have a role in CD.

METHODS

We used bacterial phylogenetic microarray to comprehensively profile the microbiota in duodenal biopsies of CD (n = 10) and HC (n = 9) children. The expression of selected mucosa-associated genes was assessed by qRT-PCR in CD and HC children and in treated CD adults (T-CD, n = 6) on gluten free diet.

RESULTS

The overall composition, diversity and the estimated microbe associated molecular pattern (MAMP) content of microbiota were comparable between CD and HC, but a sub-population profile comprising eight genus-like bacterial groups was found to differ significantly between HC and CD. In HC, increased TLR2 expression was positively correlated with the expression of tight junction protein ZO-1. In CD and T-CD, the expression of IL-10, IFN-g and CXCR6 were higher as compared to HC.

CONCLUSIONS

The results suggest that microbiota and altered expression of mucosal receptors have a role in CD. In CD subjects, the increased expression of IL-10 and IFN-g may have partly resulted from the increased TLR9 expression and signaling.