Search

Objective: The association between omega-3 fatty acids (O3FA) and celiac disease lacks sufficient investigation., Methods: Utilizing data gleaned from the 2009 to 2014 National Health and Nutrition Examination Survey (NHANES), this research comprises a sample of 13 403 adults, each aged 20 years and above. We conducted a multivariable logistic regression analysis to assess the association between dietary intake of O3FA and celiac disease. Subsequently, a two-sample Mendelian randomization was performed to estimate the unconfounded causal relationship between serum O3FA and celiac disease. The principal analytical strategy utilized the inverse-variance weighted methodology., Results: In this cross-sectional study, 48 occurrences (0.36%) of celiac disease were encompassed. In the multivariable model, there was no association between dietary intake of O3FA and cases of celiac disease (odds ratio: 1.12, 95% confidence interval: 0.47-2.66, P  = 0.792). However, serum levels of O3FA determined by genetic assay were correlated with celiac disease (inverse-variance weighted, β = 0.2439, P  = 0.0287), with no evidence of horizontal pleiotropy ( P  = 0.3689)., Conclusion: The dietary consumption of O3FA did not exhibit an association with the risk of celiac disease in this cross-sectional investigation. However, a correlation between celiac disease and serum levels of O3FA was observed in the Mendelian randomization. Further investigations, including human clinical trials, are warranted., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: The prevalence of celiac disease (CD) and hypothyroidism exhibit significant variation in different studies among patients with congenital heart disease (CHD). This study evaluated the frequency of laboratory test abnormalities in children and adolescents with CHD in Shiraz, Iran., Methods: This prospective case-control study was conducted on 223 children and adolescents with CHD and healthy individuals referred to the heart clinic affiliated with Shiraz University of Medical Sciences between February 2019 and December 2021. They were classified into case and control groups. Blood tests were performed for total IgA antibody, anti-tissue transglutaminase IgA antibody (anti-TTG Ab), T4, and thyroid stimulating hormone (TSH) and anti-thyroid peroxidase antibodies in serum, along with transthoracic echocardiography. Likewise, demographic characteristics of patients, including age, sex, weight, height, and body mass index (BMI), were recorded. Also, anti-TTG Ab levels were compared among CHD patients according to cyanosis status, gender, age (above and below five years), and BMI (under and over 18.5)., Results: Ninety-eight CHD patients and 100 healthy individuals with an average age of 5.32 ± 4.05 years (1-18 years) were examined. In children with CHD, atrial septal defect (27%), ventricular septal defect (20%), and tetralogy of Fallot (13%) were the most prevalent disorders. Only one CHD patient had an anti-TTG Ab level of 16.6 unit/mL, considered borderline for seropositive CD diagnosis. There was no difference in anti-TTG Ab levels between age (above and below five years), BMI (under and over 18.5), cyanosis status, and gender groups. Seven CHD patients had high TSH levels, three had cyanotic CHD, and one had Down syndrome. The TSH levels and non-autoimmune hypothyroidism were significantly higher in CHD patients than in normal subjects (p < 0.05)., Conclusions: According to the results of this study, the serum level of TSH and prevalence of non-autoimmune hypothyroidism were higher in patients with CHD than in normal subjects, but the serum level of anti-TTG Ab was not different between the two groups., (© 2024. The Author(s).)

Purpose: This study aimed to investigate the changes in serum Anti-Müllerian Hormone (AMH) levels, sex hormone levels, follicle-stimulating hormone (FSH)/luteinizing hormone (LH) ratio in patients with celiac disease (CeD), and their correlation with clinical characteristics and nutrient levels., Methods: This cross-sectional study collected clinical and biochemical data from a total of 67 females diagnosed with CeD and 67 healthy females within the reproductive age range of 18-44 years. The study was conducted at a tertiary hospital between September 2016 and January 2024. Both groups underwent comprehensive clinical and laboratory assessments. Serum levels of AMH and sex hormones were quantified using chemiluminescence immunoassay, and their associations with CeD clinical features and nutrient levels were thoroughly analyzed., Results: The study included 67 patients and 67 controls with a mean age of 36.7±7.6 years. No statistically significant differences were found between the two groups in mean age, BMI, FSH, LH, E 2 , P levels, FSH/LH, menstrual irregularities, abortions history, parity, and gravidity (all P>0.05). However, AMH, T, FER, FA, Zn, and Se levels were significantly lower, and PRL levels were higher in the CeD group (all P<0.05). Spearman's correlation analysis showed that AMH levels were negatively correlated with age, tTG level, disease duration, and Marsh grading (P<0.05)., Conclusions: This study highlights the association between impaired ovarian function in CeD patients and disease severity and nutrient levels. Early detection and intervention for ovarian function abnormalities are imperative to enhance fertility potential in CeD patients., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Celiac Disease (CD) is a primary malabsorption syndrome resulting from the interplay of genetic, immune, and dietary factors. CD negatively impacts daily activities and may lead to conditions such as osteoporosis, malignancies in the small intestine, ulcerative jejunitis, and enteritis, ultimately causing severe malnutrition. Therefore, an effective and rapid differentiation between healthy individuals and those with celiac disease is crucial for early diagnosis and treatment. This study utilizes Raman spectroscopy combined with deep learning models to achieve a non-invasive, rapid, and accurate diagnostic method for celiac disease and healthy controls. A total of 59 plasma samples, comprising 29 celiac disease cases and 30 healthy controls, were collected for experimental purposes. Convolutional Neural Network (CNN), Multi-Scale Convolutional Neural Network (MCNN), Residual Network (ResNet), and Deep Residual Shrinkage Network (DRSN) classification models were employed. The accuracy rates for these models were found to be 86.67%, 90.76%, 86.67% and 95.00%, respectively. Comparative validation results revealed that the DRSN model exhibited the best performance, with an AUC value and accuracy of 97.60% and 95%, respectively. This confirms the superiority of Raman spectroscopy combined with deep learning in the diagnosis of celiac disease., (© 2024. The Author(s).)

Objectives: European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) guidelines enable the diagnosis of celiac disease (CD) without biopsies in patients with immunoglobulin A (IgA)-antibodies against tissue transglutaminase (TGA-IgA) ≥ 10× the upper limit of normal (ULN) and positivity of endomysial antibodies in a second blood sample. Limited data exist comparing the biopsy versus the nonbiopsy diagnostic approach regarding long-term outcomes in CD patients. Our study aimed to investigate the influence of the diagnostic approach on adherence to gluten-free diet (GFD), serological remission (defined as normalization of TGA-IgA during follow-up (FU)) and clinical remission in CD patients with TGA-IgA ≥ 10× ULN., Methods: Retrospective multicenter study. Patients with CD and TGA-IgA ≥ 10× ULN at diagnosis were included in the study. Patients with confirmed diagnosis by biopsy were compared to patients diagnosed by nonbiopsy approach using univariate analysis, Kaplan-Meier survival curve, and logistic regression models., Results: A total of 282 CD patients (192 [68.1%] in the biopsy group; 90 [31.9%] in the nonbiopsy group) were analyzed. The median time to normalization of TGA-IgA was 16.5 months [interquartile range, IQR: 13, 28] in the biopsy and 15 months [IQR: 12, 26] in the nonbiopsy group; p = 0.14). Rates of normalized TGA-IgA at first to third-year FU were comparable between both groups. Adherence to GFD did not seem to be influenced by the diagnostic approach., Conclusions: The nonbiopsy approach is not inferior to the biopsy approach in terms of adherence to GFD and serological remission in patients with CD., (© 2024 European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Up to 30% of patients with celiac disease (CD) suffer from concurrent autoimmune disease, compared to 3% of the general population. The association between CD and the current clinical phenotypes of inflammatory myopathies (IIM) patients has not been thoroughly addressed. Assess the CD features among patients with IIM and their relationship with the clinical phenotype and the myositis specific (MSA) and associated antibodies (MAA). For this cross-sectional study, we recruited 99 adult patients classified as IIM from a tertiary center in Mexico. We assessed serum MSA, MAA, and CD-associated autoantibodies (IgA anti-tissue transglutaminase (tTG) and both IgA and IgG anti-deaminated gliadin peptide (DGP)). Patients with highly suggestive serology for CD were then tested for IgG anti-endomysium antibodies, and a duodenal biopsy was performed. 70.7% of patients were positive for at least one antibody. Nine duodenal biopsies were taken, revealing findings compatible with celiac disease in two cases. Subjects with anti-MDA5 antibodies were more likely to have positive anti-tTG IgA antibodies (OR 6.76, 95% CI 1.85-24.62, P = 0.013) and suggestive CD serology (OR 6.41, 95% CI 1.62-25.29, P = 0.009). Patients with anti-Mi2 antibodies were more likely to have positive anti-DGP IgG antibodies (OR 3.35, 95% CI 1.12-9.96, P = 0.039), while positivity for these autoantibodies was less frequent in patients with anti-NXP2 antibodies (OR 0.22, 95% CI 0.06-0.80, P = 0.035). There is a higher prevalence of serologic and definite CD in patients with IIM compared to the general population. Identifying this subgroup of patients may have prognostic and therapeutic implications. Key points • The study estimated a serological celiac disease (CD) prevalence of 70.7% in patients with idiopathic inflammatory myopathies (IIM) and a biopsy-confirmed prevalence of 2%, suggesting that IIM patients should be considered a high-risk population for CD. • We identified a significant association between serological CD and the presence of anti-MDA5 and anti-Mi2 antibodies, suggesting a potential justification for celiac disease screening in this specific subgroup of patients. • The impact of gluten-free diets on IIM patients with serological markers of CD remains untested and warrants further investigation through prospective, randomized studies., (© 2024. The Author(s), under exclusive licence to International League of Associations for Rheumatology (ILAR).)

Background and Objectives: Parkinson disease (PD), which is a neurodegenerative disorder, includes several gastrointestinal symptoms that are similar to those of Celiac disease (CD). However, the presence of celiac antibodies in PD patients has not yet been studied. Our aim in this study is to compare anti-transglutaminase (ATA) and antigliadin antibodies (AGA) as well as gastrointestinal symptoms and nutrition habits between patients with Parkinson's disease (PD) and healthy controls., Methods and Study Design: Serum AGA IgG and IgA and the ATA antibodies IgA and IgG were studied in 102 PD patients and 91 healthy controls. Gastrointestinal symptoms, specifically constipation, were investigated using the gastrointestinal system rating scale (GSRS) and the constipation rating scale (CRS). Dietary habits were also investigated and compared between the groups., Results: No significant differences were found between the two groups in terms of celiac antibodies. As expected, the hypokinetic GSRS and CRS scores were significantly higher in the PD group (p<0.001). Dietary habits, especially carbohydrate-rich diets, had a negative impact on gastrointestinal symptoms in the PD patients., Conclusions: Studies have suggested a connection between PD and CD, which infers a probable non-celiac gluten intolerance and the need to offer PD patients an elimination diet. However, the results of our study did not support any link between celiac antibodies and PD. Notwithstanding, the negative impact of a carbohydrate-rich diet in PD patients still leaves a question regarding gluten sensitivity in these patients., Competing Interests: The authors declare no potential conflict of interest

Skin autofluorescence (sAF) measurement is a non-invasive method used to assess tissue advanced glycation end product (AGE) accumulation. This study aims to characterize sAF's association with (1) glycated hemoglobin (HbA1c) values, (2) cardiovascular risk markers, and (3) common comorbidities (autoimmune thyroiditis, celiac disease) in children with type 1 diabetes (T1D)., Materials and Methods: A total of 348 children with T1D aged 3-18 years and 85 age- and gender-matched control subjects were enrolled. sAF was quantified using an AGE Reader (Diagnoptics BV, The Netherlands). The analysis covered HbA1c, blood lipid, and C-reactive protein (CRP) levels, ambulatory blood pressure monitoring records, and body composition parameters. The associations between variables and sAF were assessed using the Mann-Whitney U test and Spearman correlation., Results: We observed significantly higher sAF values in the T1D group compared to the control (1.40 [1.27-1.53] vs. 1.20 [1.07-1.30, AU]; p = 0.004), consistent across all tested age groups. In the T1D group, sAF was positively correlated with current HbA1c, mean of historical HbA1c values, and T1D duration (r values, respectively: 0.27, 0.22, 0.14, all p < 0.01). Percentage of body fat was positively correlated with sAF (r = 0.120; p = 0.044). No significant correlations were found between sAF and lipid fractions, Z-score of BMI, parameters from 24 h ambulatory blood pressure monitoring, or the amount of albumin excreted in urine. sAF was positively correlated with CRP (r = 0.17, p < 0.05). sAF was significantly higher in patients with concomitant celiac disease (1.53 [1.43-1.63] vs. 1.40 [1.27-1.53, AU], p = 0.001)., Conclusion: Among young T1D patients with relatively brief diabetes duration, sAF effectively mirrors prior glycemic control, as presented by historical average HbA1c. However, associations with conventional CV risk markers are not evident. The higher sAF values in patients with celiac disease warrant further exploration.

In its conventional form, celiac disease (CeD) is characterized by both positive serology and flat villi in the duodenum, and is well known by gastroenterologists and general practitioners. The aim of this review was to shed light on 2 neglected and not yet well-defined celiac phenotypes, that is, seronegative and ultrashort CeD. Seronegative CeD can be suspected in the presence of flat villi, positive HLA-DQ2 and/or HLA-DQ8, and the absence of CeD antibodies. After ruling out other seronegative enteropathies, the diagnosis can be confirmed by both clinical and histologic improvements after 1 year of a gluten-free diet. Ultrashort CeD is characterized by the finding of flat villi in the duodenal bulb in the absence of mucosal damage in the distal duodenum and with serologic positivity. Data on the prevalence, clinical manifestations, histologic lesions, genetic features, and outcome of seronegative and ultrashort CeD are inconclusive due to the few studies available and the small number of patients diagnosed. Some additional diagnostic tools have been developed recently, such as assessing intestinal transglutaminase 2 deposits, flow cytometry technique, microRNA detection, or proteomic analysis, and they seem to be useful in the identification of complex cases. Further cooperative studies are highly desirable to improve the knowledge of these 2 still-obscure variants of CeD., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Introduction and Aim: Celiac disease is one of the most common autoimmune disorders. This study aimed to evaluate the relationship between celiac disease and wheat sensitization., Subjects and Methods: In the current study, children aged < 18 years with confirmed celiac disease were included. Data were analyzed using SPSS., Results: Gastrointestinal problems were the most common indication for evaluation in terms of celiac disease. Prick and patch tests were positive in 43.4% and 34% respectively., Conclusion: Prick test and patch test for wheat sensitization were positive in about 30-45% of the children for celiac disease., (© 2024. The Author(s).)

Objective: We aimed to examine the effect of remission status on thiol-disulfide homeostasis in celiac patients and thus to indirectly determine the effect of oxidative stress and inflammation caused by non-compliance with the diet., Methods: Between February 2019 and December 2021, 117 patients diagnosed with celiac disease were included in this prospective randomized and controlled study. In addition to routine tests of celiac patients, thiol and disulfide measurements were made from the blood both at the beginning of the study and at the end of the first year., Results: While 52 of the patients (44.4%) were in remission, 65 patients (55.6%) were not. There was an evident increase in native thiol levels of the patients who were initially not in remission but went into at the end of the first year (347.4±46.7 μmol/L vs. 365.3±44.0 μmol/L; p=0.001). Mean plasma disulfide levels of patients with celiac going into remission became reduced in the first year from the level of 14.5±5.1 μmol/L down to 8.9±4.2 μmol/L (p<0.001). In celiac patients who entered remission, disulfide and anti-tissue transglutaminase immunoglobulin A levels decreased in a correlation (r=0.526; p<0.001)., Conclusion: Not being in remission in celiac disease leads to increased oxidative stress, and thiol-disulfide homeostasis is an indirect indicator of this. Additionally, providing remission in celiac patients reduces oxidative stress.

Introduction: Circulating tissue transglutaminase immunoglobulin A concentration is a sensitive and specific indicator of celiac disease, but discrepancies between serologic and histologic findings occur. We hypothesized that fecal markers of inflammation and protein loss would be greater in patients with untreated celiac disease than in healthy controls. Our study aims to evaluate multiple fecal and plasma markers in celiac disease and correlate these findings with serologic and histologic findings as noninvasive means of evaluating disease activity., Methods: Participants with positive celiac serologies and controls with negative celiac serologies were prospectively enrolled before upper endoscopy. Blood, stool, and duodenal biopsies were collected. Concentrations of fecal lipocalin-2, calprotectin, and alpha-1-antitrypsin and plasma lipocalin-2 were determined. Biopsies underwent modified Marsh scoring. Significance was tested between cases and controls, modified Marsh score and tissue transglutaminase immunoglobulin A concentration., Results: Lipocalin-2 was significantly elevated in the stool ( P = 0.006) but not the plasma of participants with positive celiac serologies. There was no significant difference in fecal calprotectin or alpha-1 antitrypsin between participants with positive celiac serologies and controls. Fecal alpha-1 antitrypsin >100 mg/dL was specific, but not sensitive for biopsy-proven celiac disease., Discussion: Lipocalin-2 is elevated in the stool but not the plasma of patients with celiac disease suggesting a role of local inflammatory response. Calprotectin was not a useful marker in the diagnosis of celiac disease. While random fecal alpha-1 antitrypsin was not significantly elevated in cases compared with controls, an elevation of greater than 100 mg/dL was 90% specific for biopsy-proven celiac disease., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Introduction and Aims: Celiac disease (CD) is an autoimmune enteropathy that develops in genetically susceptible individuals. The typical gastrointestinal manifestation is diarrhea but symptoms of dyspepsia, such as epigastric pain, nausea, or satiety, can sometimes appear. Previous studies have reported that the prevalence of CD in patients with dyspepsia can be as high as 7%. The aim of the present study was to evaluate CD seroprevalence in subjects with dyspeptic symptoms and a control group in a Mexican population., Material and Methods: A case-control study was conducted on blood donors that answered the PAGI-SYM questionnaire for dyspepsia and in whom IgA antibodies to tissue transglutaminase 2 (IgA anti-tTG2) and IgG antibodies to deamidated gliadin peptide (IgG anti-DGP) were determined. CD seroprevalence in subjects with dyspeptic symptoms and in asymptomatic subjects was compared., Results: A total of 427 subjects (76.3% men), with a mean patient age of 34 years (range of 18-65 years) were included. Of those participants, 87 (20.3%) had symptoms of dyspepsia (group A) and 340 (79.6%) were asymptomatic (group B). Antibodies were positive in one (1.15%) of the group A subjects (1/87, 95% CI 0.2-6 %), whereas they were positive in 4 (1.18%) of the group B subjects (4/340, 95% CI 0.4-2.9%, p = 0.59)., Conclusions: CD seroprevalence in the study population with dyspeptic symptoms (1%) was not different from that of the control population. Thus, CD screening in Mexican patients with dyspepsia is not justified., (Copyright © 2023 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.)

Background: The relationship between Vitamin D levels and pediatric celiac disease (CD) remains controversial. In this study, we conducted a systematic review and meta-analysis to examine the relationship between Vitamin D and pediatric CD., Methods: We screened relevant studies from PubMed, EMBASE, and Web of Science published in English from January 1, 2000, to August 1, 2023. The included studies were assessed according to the STROBE checklist. Heterogeneity was quantified by Cochran's Q test and the I 2 statistic. Publication bias was estimated by Begg's test and Egger's test. Meta-regression was used to detect potential sources of heterogeneity., Results: A total of 26 studies were included in the meta-analysis. Nineteen articles compared 25(OH)D3 levels between CD patients and control groups, average 25-hydroxyvitamin D 3 [25(OH)D 3 or calcidiol], and 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 or calcitriol] levels, as the main forms of Vitamin D, there was a significant difference in CD patients and healthy controls (weighted mean difference (WMD) = - 5.77, 95% confidence interval (CI) = [- 10.86, - 0.69] nmol/L). Meanwhile, eleven articles reported the numbers of patients and controls with Vitamin D deficiency, there was a significant difference in the incidence of 25(OH)D 3 deficiency between CD patients and healthy controls (odds ratio 2.20, 95% CI= [1.19, 4.08]). Nine articles reported changes in 25(OH)D 3 levels before and after administering a GFD in patients with CD, the result of this study revealed the increase of 25(OH)D 3 levels in CD patients after a gluten-free diet (GFD) (WMD = - 6.74, 95% CI = [- 9.78, - 3.70] nmol/L)., Conclusions: Vitamin D levels in pediatric CD patients were lower than in healthy controls, and 25(OH)D 3 deficiency was more prevalent in CD patients. We found that 25(OH)D 3 levels were elevated in CD patients after GFD, which is consistent with previous research. Further well-designed, longitudinal, prospective cohort studies focusing on the role of Vitamin D in the pathogenesis of CD are therefore needed., (© 2024. The Author(s).)

Background: There is some evidence of a higher prevalence of coeliac disease (CD) among patients with SLE than in the general population. However, the prevalence estimates vary substantially., Objective: To investigate the prevalence of CD among patients with SLE through systematic review and meta-analysis., Methods: We performed searches in the databases of Medline, Embase, Cochrane and Web of Science Core Collection between 1 January 1990 and 9 July 2023. A total of 2053 publications were rendered in the searches, of which 68 were reviewed in full text and 14 included in the analyses. Primary analysis estimated the pooled prevalence of biopsy-verified CD in patients with SLE. In the secondary analysis, the prevalence of serological markers indicative of CD was investigated. The quality of studies was appraised using the Joanna Briggs Institute Critical Appraisal Tool. We conducted meta-regression analyses to investigate associations between the prevalence of CD in individuals with SLE and publication year, study population size, CD prevalence in the general population, proportion of females and quality assessment score., Results: A total of 14 studies met the inclusion criteria, of which 11 were included in the primary analysis of biopsy-verified CD. Among 1238 patients with SLE, 14 had CD. The weighted pooled prevalence of CD was 0.7% (95% CI 0.0 to 1.8). The weighted pooled prevalence of CD serological markers in 1063 patients with SLE was 3.7% (95% CI 1.4 to 6.7). In meta-regression analyses, no associations between CD prevalence and study characteristics, demographics and quality assessment scores were found., Conclusions: In this meta-analysis, we found a weighted pooled prevalence of biopsy-verified CD in patients with SLE comparable with the prevalence in the general population. Our findings do not support routine screening for CD in patients with SLE. However, individual screening could be considered in cases of clinical suspicion and additional risk factors for CD., Prospero Registration Number: CRD42022339594., Competing Interests: Competing interests: AF served as speaker and advisory board member for Janssen and Tillotts Pharma., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Objectives: Increased intestinal permeability seems to be a key factor in the pathogenesis of autoimmune diseases, including celiac disease (CeD). However, it is unknown whether increased permeability precedes CeD onset. This study's objective was to determine whether intestinal permeability is altered before celiac disease autoimmunity (CDA) in at-risk children. We also examined whether environmental factors impacted zonulin, a widely used marker of gut permeability., Methods: We evaluated 102 children in the CDGEMM study from 2014-2022. We included 51 CDA cases and matched controls, who were enrolled for 12 months or more and consumed gluten. We measured serum zonulin from age 12 months to time of CDA onset, and the corresponding time point in controls, and examined clinical factors of interest. We ran a mixed-effects longitudinal model with dependent variable zonulin., Results: Children who developed CDA had a significant increase in zonulin in the 18.3 months (range 6-78) preceding CDA compared to those without CDA (slope differential = β = 0.1277, 95% CI: 0.001, 0.255). Among metadata considered, zonulin trajectory was only influenced by increasing number of antibiotic courses, which increased the slope of trajectory of zonulin over time in CDA subjects (P = .04)., Conclusions: Zonulin levels significantly rise in the months that precede CDA diagnosis. Exposure to a greater number of antibiotic courses was associated with an increase in zonulin levels in CDA subjects. This suggests zonulin may be used as a biomarker for preclinical CeD screening in at-risk children, and multiple antibiotic courses may increase their risk of CDA by increasing zonulin levels., (Copyright © 2024 by the American Academy of Pediatrics.)

Celiac disease (CD) is an autoimmune disease with inflammatory characteristics, having a condition of chronic malabsorption, affecting approximately 1% of the population at any age. In recent years, a concrete correlation between eating disorders and CD has emerged. Hypothalamus plays a central role in determining eating behaviour, regulating appetite and, consequently, food intake. One hundred and ten sera from celiac patients (40 active and 70 following a gluten-free diet) were tested for the presence of autoantibodies against primate hypothalamic periventricular neurons by immunofluorescence and by a home-made ELISA assay. In addition, ghrelin was measured by ELISA. As control, 45 blood serums from healthy age matched were analysed. Among active CD, all patients resulted positive for anti-hypothalamus autoantibodies and sera showed significantly higher levels of ghrelin. All of the free-gluten CD were negative for anti-hypothalamus autoantibodies and had low levels of ghrelin, as well as healthy controls. Of interest, anti-hypothalamic autoantibodies directly correlate with anti-tTG amounts and with mucosal damage. In addition, competition assays with recombinant tTG showed a drastically reduction of anti-hypothalamic serum reactivity. Finally, ghrelin levels are increased in CD patients and correlated with anti-tTG autoantibodies and anti-hypothalamus autoantibodies. This study demonstrates for the first time the presence of anti-hypothalamus antibodies and their correlation with the severity of the CD. It also allows us to hypothesize the role of tTG as a putative autoantigen expressed by hypothalamic neurons., (© 2023. The Author(s).)

Introduction: Few data are available regarding the trend of IgA anti-transglutaminase antibodies (TGA-IgA) in children with celiac disease (CD) on a gluten-free diet (GFD). Our aim is to examine the normalization time of CD serology in a large pediatric population, and its predictors., Material and Methods: We retrospectively evaluated the normalization time of TGA-IgA and its predictive factors (age, sex, ethnicity, symptoms, associated diabetes/thyroiditis, Marsh stage, TGA-IgA and endomysial antibody levels at diagnosis, diet adherence), in 1024 children diagnosed from 2000 to 2019 in three pediatric Italian centers, on a GFD., Results: TGA-IgA remission was reached in 67,3%, 80,7%, 89,8% and 94,9% after 12, 18, 24 and 36 months from starting a GFD, respectively (median time = 9 months). TGA-IgA >10´upper limit of normal at diagnosis (HR = 0.56), age 7-12 years old (HR = 0.83), poor compliance to diet (HR = 0.69), female sex (HR = 0.82), non-Caucasian ethnicity (HR = 0.75), and comorbidities (HR = 0.72) were independent factors significantly associated with longer time to normalization., Conclusions: Our population is the largest in the literature, with the majority of patients normalizing CD serology within 24 months from starting a GFD. We suggest a special attention to patients with comorbidities, language barriers or age 7-12 years for a proper management and follow-up., (Copyright © 2021 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Inflammatory states are associated with anemia of chronic disease and acute infection. Hepcidin, a regulator of iron metabolism, is involved in iron pathophysiology during inflammation. We investigated biochemical characteristics in children with anemia from different causes. Four patient groups (n = 38; mean age: 12.44 ± 4.35 years) were studied: (1) inflammatory bowel disease (IBD, 10 patients); (2) iron deficiency anemia (IDA, 12); (3) celiac disease (CD, 8); (4) acute infection (AI, 8). Laboratory measurements were evaluated at diagnosis: blood count, serum iron, transferrin, ferritin, vitamin B 12 , folic acid, CRP, erythropoietin, hepcidin and soluble transferrin receptor (sTfR). IDA patients had the lowest Hgb (6.9 ± 1.7 g/dL), MCV (63.2 ± 7.2 fL), iron (16.8 ± 13.5 µg/dL), ferritin (4.5 ± 4.5 ng/mL) and hepcidin (3.1 ± 0.8 ng/mL) values, and the highest transferrin and sTfR values. AI patients had the highest ferritin (156.2 ± 124.5 ng/mL), CRP (144.6 ± 94 mg/L) and hepcidin (74.67 ± 12.3 ng/ml) values. Overall, hepcidin levels correlated with CRP and with ferritin (r = 0.83 and 0.85, respectively). Elucidating specific etiology-related biochemical profiles in pediatric patients with anemia from different causes using a combination of laboratory biomarkers, including hepcidin, can help physicians treat the anemia., (© 2022. The Author(s).)

Introduction: Treated patients with celiac disease (CeD) and nonceliac gluten sensitivity (NCGS) report acute, transient, incompletely understood symptoms after suspected gluten exposure. To determine whether (i) blinded gluten exposure induces symptoms, (ii) subjects accurately identify gluten exposure, and (iii) serum interleukin-2 (IL-2) levels distinguish CeD from NCGS subjects after gluten exposure., Methods: Sixty subjects (n = 20 treated, healed CeD; n = 20 treated NCGS; n = 20 controls) were block randomized to a single, double-blind sham (rice flour) or 3-g gluten challenge with 72-hours follow-up. Twelve serial questionnaires (100 mm visual analog scale; pain, bloating, nausea, and fatigue) and 10 serial plasma samples were collected. Mucosal permeability was assessed using both urinary lactulose-13C mannitol ratios and endoscopic mucosal impedance., Results: Thirty-five of 40 (83%) subjects with CeD and NCGS reported symptoms with gluten (8 CeD, 9 NCGS) and sham (9 CeD, 9 NCGS) compared with 9 of 20 (45%) controls after gluten (n = 6) and sham (n = 3). There was no significant difference in symptoms among groups. Only 2 of 10 subjects with CeD and 4 of 10 NCGS identified gluten, whereas 8 of 10 subjects with CeD and 5 of 10 NCGS identified sham. A significant plasma IL-2 increase occurred only in subjects with CeD after gluten, peaking at 3 hours and normalizing within 24 hours postchallenge despite no significant intestinal permeability change from baseline., Discussion: Symptoms do not reliably indicate gluten exposure in either subjects with CeD or NCGS. IL-2 production indicates a rapid-onset gluten-induced T-cell activation in CeD despite long-standing treatment. The effector site is unknown, given no increased intestinal permeability after gluten., (Copyright © 2021 by The American College of Gastroenterology.)

Background: The general practice is to screen patients with autoimmune thyroid disease for celiac disease (CD); however, optimal timing for CD screening for patients with Graves'Disease (GD) has not been identified yet. The aim of the study was to show whether positive celiac antibodies persist after euthyroidism is achieved., Materials and Methods: Serum samples were collected from 35 patients with GD (23 female and 12 male) who applied to the endocrine outpatient clinic. Patients and healthy controls were screened for CD with IgG and IgA antigliadin antibodies (IgG - AGA and IgA - AGA), IgA endomysial antibody (IgA-EMA) and IgA tissue transglutaminase antibody (IgA anti-tTG). These antibodies were reevaluated when patients were euthyroid under antithyroid therapy. Small intestine biopsy was offered to the patients who remained antibody positive after being euthyroid., Results: Screening 35 patients with GD revealed positive results for IgA-AGA ( n = 6/35, 17%), IgG-AGA ( n = 9/35, 26%), IgA-EmA ( n = 2/35, 6%) and IgA-tTG ( n = 2/35, 6%). No patient had multiple antibodies positive. Selective IgA deficiency was not detected in patients and controls. When patients were euthyroid, baseline positive IgA-AGA, IgG-AGA, and IgA-EmA became negative, while positive anti-tTG persisted in two patients. Endoscopic duodenal biopsy showed a normal villi/crypts ratio in these patients. None of the controls had positive antibodies., Conclusion: Due to possibility of false seropositivity of celiac antibodies in patients with Graves' thyrotoxicosis, one should defer testing for CD until euthyroidism has been achieved.

Background & Aims: Celiac disease (CeD), an immune-mediated disease with enteropathy triggered by gluten, affects ~1% of the general European population. Currently, there are no biomarkers to predict CeD development. MicroRNAs (miRNAs) are short RNAs involved in post-transcriptional gene regulation, and certain disease- and stage-specific miRNA profiles have been found previously. We aimed to investigate whether circulating miRNAs can predict the development of CeD., Methods: Using next-generation miRNA-sequencing, we determined miRNAs in >200 serum samples from 53 participants of the PreventCD study, of whom 33 developed CeD during follow-up. Following study inclusion at 3 months of age, samples were drawn at predefined ages, diagnosis (first anti-transglutaminase antibody (TGA) positivity or diagnostic biopsy) and after the start of a gluten-free diet (GFD). This allowed identification of circulating miRNAs that are deregulated before TGA positivity. For validation of the biomarkers for CeD and GFD response, two additional cohorts were included in subsequent meta-analyses. Additionally, miRNAs were measured in duodenal biopsies in a case-control cohort., Results: 53 circulating miRNAs were increased (27) or decreased (26) in CeD versus controls. We assessed specific trends in these individual miRNAs in the PreventCD cohort by grouping the pre-diagnostic samples of the CeD patients (all had negative TGA) by how close to seroconversion (first sample positive TGA) the samples were taken. 8/53 miRNAs differed significantly between controls and samples taken <1 year before TGA positivity: miR-21-3p, miR-374a-5p, 144-3p, miR-500a-3p, miR-486-3p let-7d-3p, let-7e-5p and miR-3605-3p. 6/26 downregulated miRNAs reconstituted upon GFD, including miR-150-5p/-3p, whereas no upregulated miRNAs were downregulated upon GFD. 15/53 biomarker candidates also differed between CeD biopsies and controls, with a concordant direction, indicating that these circulating miRNAs might originate from the intestine., Conclusions: We identified 53 circulating miRNAs that are potential early biomarkers for CeD, of which several can be detected more than a year before TGA positivity and some start to normalize upon GFD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tan, Coutinho de Almeida, Modderman, Stachurska, Dekens, Barisani, Meijer, Roca, Martinez-Ojinaga, Shamir, Auricchio, Korponay-Szabó, Castillejo, Szajewska, Koletzko, Zhernakova, Kumar, Li, Visschedijk, Weersma, Troncone, Mearin, Wijmenga, Jonkers and Withoff.)

Background: Celiac disease (CeD) is an autoimmune intestinal disorder caused by gluten protein consumption in genetically predisposed individuals. As biopsy sampling is an invasive procedure, finding novel noninvasive serological markers for screening of at-risk CeD population is a priority. Metabolomics is helpful in monitoring metabolite changes in body fluids and tissues. In the present study, we evaluated serum metabolite levels of CeD patients relative to healthy controls with the aim of introducing new biomarkers for population screening., Method: We compared the serum metabolic profile of CeD patients ( n = 42) and healthy controls ( n = 22) using NMR spectroscopy and multivariate analysis., Result: 25 metabolites were identified by serum metabolic profiling. Levels of 3-hydroxyisobutyric acid and isobutyrate showed significant differences in CeD patients' samples compared with healthy controls ( p < 0.05). According to pathway analysis, our data demonstrated that changes in nine metabolic pathways were significantly disrupted/affected in patients with CeD. These enriched pathways are involved in aminoacyl-tRNA biosynthesis; primary bile acid biosynthesis; nitrogen metabolism; glutamine and glutamate metabolism; valine, leucine, and isoleucine biosynthesis and degradation; taurine and hypotaurine metabolism; glyoxylate and dicarboxylate metabolism; glycine, serine, and threonine metabolism; and arginine biosynthesis., Conclusion: In summary, our results demonstrated that changes in the serum level of 25 metabolites may be useful in distinguishing CeD patients from healthy controls, which have the potential to be considered candidate biomarkers of CeD., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Ensieh Khalkhal et al.)

Objective: The co-occurrence of coeliac disease (CD) and type 1 diabetes mellitus (T1DM) is well described and is mainly explained by sharing of common pathogenic mechanisms, such as common high-risk human lymphocyte antigen (HLA) genotypes (DR-DQ)., Patients and Methods: We describe a 12-year-old female patient with T1DM who presented with prolonged and severe glucose dysregulation. Extensive investigations, including coeliac screen, were negative., Results: 3 years after glucose dysregulation manifested, coeliac screen testing was positive and coeliac disease was confirmed with bowel biopsy. Compliance to a gluten-free diet resulted in improvement of glucose control and seronegativity 9 months post-diagnosis., Conclusions: This is the first case report describing delayed seropositivity of CD and suggests that CD enteropathy may precede positive serology and could cause severe glucose dysregulation in patients with T1DM.

The association between eosinophilic esophagitis and celiac disease is still controversial and its prevalence is highly variable. We aimed to investigate the prevalence of esophageal eosinophilia and eosinophilic esophagitis in a large group of children with celiac disease, prospectively followed over 11 years., Methods: Prospective observational study performed between 2008 and 2019. Celiac disease diagnosis was based on ESPGHAN criteria. At least four esophageal biopsies were sampled in patients who underwent endoscopy. The presence of at least 15 eosinophils/HPF on esophageal biopsies was considered suggestive of esophageal eosinophilia; at the same time, eosinophilic esophagitis was diagnosed according to the International Consensus Diagnostic Criteria for Eosinophilic Esophagitis., Results: A total of 465 children (M 42% mean age 7.1 years (range: 1-16)) were diagnosed with celiac disease. Three hundred and seventy patients underwent endoscopy, and esophageal biopsies were available in 313. The prevalence of esophageal eosinophilia in children with celiac disease was 1.6% (95% CI: 0.54-2.9%). Only one child was diagnosed as eosinophilic esophagitis; we calculated a prevalence of 0.3% (95% CI: 0.2-0.5%). The odds ratio for an association between eosinophilic esophagitis and celiac disease was at least 6.5 times higher (95% CI: 0.89-47.7%; p = 0.06) than in the general population., Conclusion: The finding of an increased number of eosinophils (>15/HPF) in celiac patients does not have a clinical implication or warrant intervention, and therefore we do not recommend routine esophageal biopsies unless clinically indicated.

Introduction & Aim: Anti-tissue transglutaminase antibody (tTGA) titer is used during the follow-up of celiac patients to evaluate gluten-free diet (GFD) responsiveness. However, no clear data are available on this issue. The aim of this study was to evaluate tTGA significance during celiac disease (CD) monitoring., Methods: From January 2017 to January 2020, consecutive CD patients on a GFD with persistent positive tTGA were enrolled. Antibody titres were evaluated on a yearly basis from CD diagnosis to the last follow-up. Urinary gluten detection tests, duodenal histology and capsule enteroscopy (CE) were performed. A tTGA-positive cohort was compared with a control group composed of 212 treated CD patients with negative tTGA., Results: 65 patients (12% males, median age at enrollment and CD diagnosis, 37 (14-86) and 31 (1-76), respectively, median follow up 4 (1-26) years) presented with positive tTGA during follow-up. Overall, the tTGA titres were 3 (1-79) fold increased (ULN). Three different tTGA trends were recognized: (I) 36 (55%) patients with a progressive titres decrease; (II) 16 (25%) patients with a fluctuating behavior; (III) 13 (20%) patients with a steady state or increased titres. tTGA+ patients did not present with different clinical and demographic parameters. Duodenal atrophy was present in 10% vs. 36% of the tTGA positive vs. negative group ( p < 0.005), respectively. Gluten detection results were positive in 3 (8%) cases, all in the III group. In tTGA+ patients, CE did not identify any CD-related complications., Conclusions: tTGA positivity during CD follow up did not present a relevant clinical significance without association with autoimmune comorbidities and mucosal damage.

Objectives: Children with antibody positive type 1 diabetes mellitus (type 1 diabetes) are at an increased risk of developing celiac disease (CD) which suggests a common autoimmune basis with both high-risk human lymphocyte antigen (HLA) and non-HLA factors playing a role in the pathophysiology. We aim to describe the prevalence, immune profile, and clinical characteristics of children with CD who have type 1 diabetes mellitus in Qatar., Methods: All children (aged 0-18 years) attending a regional diabetes clinic with antibody positive type 1 diabetes were screened for CD. Measurement of tissue transglutaminase IgA and IgG as well as anti-endomysial antibody, was done, clinical details about the birth history, family history of diabetes and CD, age of onset, and ethnicity were collected., Results: Out of the 1,325 children with antibody positive type 1 diabetes, 54 were identified to have CD on screening and then confirmed on small bowel biopsy. The prevalence of CD in the type 1 diabetes childhood population in Qatar is 4.07%. CD and type 1 diabetes were more prevalent in the Qatari children (n=32) as compared to non-Qatari (n=22) and occurred mostly in the age group 6-10 years. The most common type 1 diabetes antibodies in children with CD were glutamic acid decarboxylase and insulin autoantibody. Twelve subjects were asymptomatic for CD symptoms and picked up only on screening., Conclusions: The prevalence of CD in children with type 1 diabetes in Qatar is comparable to reports from around the world. Many children were asymptomatic and thus routine screening is recommended., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Celiac disease (CD) is an autoimmune chronic inflammatory disease occurring in genetically predisposed individuals in response to the intake of gluten. Clinical presentation can be heterogeneous. Iron-deficient anemia (IDA) is one of the most common extra-intestinal manifestations of CD. Although IDA usually reverts with a gluten-free diet (GFD), some patients show persistent IDA, the mechanisms of which are poorly understood. Recent studies suggest an association between the rs855791 polymorphism in the TMPRSS6 gene and persistent IDA in adults with CD. The current study aimed to assess the potential link between rs855791 and persistent IDA in pediatric patients with CD. The study included 106 children diagnosed with CD between 2015 and 2019. Clinical and blood parameters (including blood count, serum iron) were collected at diagnosis and after ≥12 months of GFD, and the rs855791 genotype was assessed for each patient. IDA was present at diagnosis in 25 patients (23.6%); only three (3%) had persistent IDA after GFD. The prevalence of rs855791 genotypes was 9% ( n = 10) for TT, 53% ( n = 56) for CT, and 38% ( n = 40) for CC. There was a tendency toward a higher proportion of the T allele in patients with IDA and lower hemoglobin in the TT genotype but without statistical significance. An association between rs855791 and persistent IDA was not observed. These findings suggest that persistent IDA is uncommon in pediatric patients with CD. The prevalence of rs855791 in children with CD is reported for the first time.

Celiac disease (CD) is an autoimmune enteropathy linked to alterations of metabolism. Currently, limited untargeted metabolomic studies evaluating differences in the plasma metabolome of CD subjects have been documented. We engage in a metabolomic study that analyzes plasma metabolome in 17 children with CD treated with a gluten-free diet and 17 healthy control siblings in order to recognize potential changes in metabolic networks. Our data demonstrates the persistence of metabolic defects in CD subjects in spite of the dietary treatment, affecting a minor but significant fraction (around 4%, 209 out of 4893 molecular features) of the analyzed plasma metabolome. The affected molecular species are mainly, but not exclusively, lipid species with a particular affectation of steroids and derivatives (indicating an adrenal gland affectation), glycerophospholipids (to highlight phosphatidic acid), glycerolipids (with a special affectation of diacylglycerols), and fatty acyls (eicosanoids). Our findings are suggestive of an activation of the diacylglycerol-phosphatidic acid signaling pathway in CD that may potentially have detrimental effects via activation of several targets including protein kinases such as mTOR, which could be the basis of the morbidity and mortality connected with untreated CD. However, more studies are necessary to validate this idea regarding CD.

Background: It is not known if genetic background, characteristics at diagnosis, physical and psychological well-being, and adherence to a gluten-free diet are comparable between patients with familial or sporadic celiac disease. These issues were investigated in a follow-up study., Methods: Altogether 1064 patients were analyzed for celiac disease-associated serology, predisposing HLA-DQ, and non-HLA genotypes. Medical data were collected from patient records and supplementary interviews. Current symptoms and quality of life were further evaluated with the Gastrointestinal Symptom Rating Scale (GSRS), the Psychological General Well-Being questionnaire (PGWB), and Short Form 36 (SF-36) questionnaires., Results: Familial and sporadic groups differed (P < 0.001) in the reason for diagnosis and clinical presentation at diagnosis, familial patients being more often screen-detected (26% vs. 2%, P < 0.001) and having less often gastrointestinal (49% vs. 69%) and severe symptoms (47% vs. 65%). The groups were comparable in terms of histological damage, frequency of malabsorption, comorbidities, childhood diagnoses, and short-term treatment response. At the time of the study, familial cases reported fewer symptoms (21% vs. 30%, P = 0.004) and lower prevalence of all (78% vs. 86%, P = 0.007), neurological (10% vs. 15%, P = 0.013), and dermatological (9% vs. 17%, P = 0.001) comorbidities. Dietary adherence and GSRS scores were comparable, but familial cases had better quality of life according to PGWB and SF-36. High-risk genotype HLA-DQ2.5/DQ2.5 was more frequent among familial cases, and four non-HLA SNPs were associated with familial celiac disease., Conclusions: Despite the greater proportion of high-risk genotypes, familial cases had milder symptoms at presentation than did sporadic cases. Worse experience of symptoms and poorer quality of life in sporadic disease indicate a need for intensified support.

Celiac disease (CD) and autoimmune thyroid diseases (AITD) like Hashimoto's thyroiditis (HT) and Graves' disease (GD) frequently coexist, entailing numerous potential impacts on diagnostic and therapeutic approaches. Possible correlations might exist through gut microbiota, regulating the immune system and inflammatory responses, promoting autoimmune diseases, as well as shared cytokines in pathogenesis pathways, cross-reacting antibodies or malabsorption of micronutrients that are essential for the thyroid like iron or vitamin D. Vitamin D deficiency is a common finding in patients with AITD, but might protect from autoimmunity by wielding immunoregulatory and tolerogenic impacts. Additionally, vitamin D is assumed to be involved in the onset and progression of CD, presumably plays a substantial protective role for intestinal mucosa and affects the thyroid via its immunomodulatory effects. Iron is an essential micronutrient for the thyroid gland needed for effective iodine utilization by the iron-dependent enzyme thyroid iodine peroxidase (TPO). Despite being crucial for thyroid hormone synthesis, iron deficiency (ID) is a common finding in patients with hypothyroidism like HT and is frequently found in patients with CD. A literature research was conducted to examine the interplay between CD, AITD, vitamin D and iron deficiency. This narrative review highlights the relevant correlation of the two disease entities CD and AITD, their reciprocal impact and possible therapeutic options that should be further explored by future studies.

Improved blood tests assessing the functional status of rare gluten-specific CD4+ T cells are needed to effectively monitor experimental therapies for coeliac disease (CD). Our aim was to develop a simple, but highly sensitive cytokine release assay (CRA) for gluten-specific CD4+ T cells that did not require patients to undergo a prior gluten challenge, and would be practical in large, multi-centre clinical trials. We developed an enhanced CRA and used it in a phase 2 clinical trial ("RESET CeD") of Nexvax2, a peptide-based immunotherapy for CD. Two participants with treated CD were assessed in a pilot study prior to and six days after a 3-day gluten challenge. Dye-dilution proliferation in peripheral blood mononuclear cells (PBMC) was assessed, and IL-2, IFN-γ and IL-10 were measured by multiplex electrochemiluminescence immunoassay (ECL) after 24-hour gluten-peptide stimulation of whole blood or matched PBMC. Subsequently, gluten-specific CD4+ T cells in blood were assessed in a subgroup of the RESET CeD Study participants who received Nexvax2 (maintenance dose 900 μg, n = 12) or placebo (n = 9). The pilot study showed that gluten peptides induced IL-2, IFN-γ and IL-10 release from PBMCs attributable to CD4+ T cells, but the PBMC CRA was substantially less sensitive than whole blood CRA. Only modest gluten peptide-stimulated IL-2 release could be detected without prior gluten challenge using PBMC. In contrast, whole blood CRA enabled detection of IL-2 and IFN-γ before and after gluten challenge. IL-2 and IFN-γ release in whole blood required more than 6 hours incubation. Delay in whole blood incubation of more than three hours from collection substantially reduced antigen-stimulated IL-2 and IFN-γ secretion. Nexvax2, but not placebo treatment in the RESET CeD Study was associated with significant reductions in gluten peptide-stimulated whole blood IL-2 and IFN-γ release, and CD4+ T cell proliferation. We conclude that using fresh whole blood instead of PBMC substantially enhances cytokine secretion stimulated by gluten peptides, and enables assessment of rare gluten-specific CD4+ T cells without requiring CD patients to undertake a gluten challenge. Whole blood assessment coupled with ultra-sensitive cytokine detection shows promise in the monitoring of rare antigen-specific T cells in clinical studies., Competing Interests: ImmusanT, Inc., Cambridge, Massachusetts USA provided funding for the study. ImmusanT was involved in the study design, collection of data, and the decision to submit it for publication. RA, GG, SW, ES, RZ, KG, KN, KT, LW, and JD were employees of ImmusanT, Inc. JT-D has served as an advisor to ImmusanT, Inc. RA and JT-D are inventors of Patents owned or licensed by ImmusanT, Inc. that relate to gluten peptide immunotherapy and diagnostics. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Hardy, Goel, Russell, Chen Yi Mei, Brown, Wang, Szymczak, Zhang, Goldstein, Neff, Williams, Truitt, Dzuris, Tye-Din and Anderson.)

Objective: Hashimoto's thyroiditis is known to cluster with other systemic autoimmune disorders. Rheumatic manifestations, such as a seronegative non-erosive polyarthritis have been described. The aim of this study was to evaluate the characteristics and the prevalence of rheumatic features in thyroiditis patients, and to ascertain whether the association with systemic autoimmune disorders improved the arthritis manifestations., Methods: In total, 180 thyroiditis patients were enrolled. Major clinical and demographic characteristics have been recorded. Patients underwent a rheumatological clinical assessment and extra-articular manifestations allowing for a differential diagnosis with systemic autoimmune diseases and spondyloarthropathy. Presence of systemic autoimmune diseases was recorded., Results: A total of 8.33% of thyroiditis patients shown a peripheral inflammatory arthritis (P = 0.002). Female gender (P = 0.042) and thyroid peroxidase (TPOAbs) positivity (P = 0.001) were more frequent. In total, 37 patients had systemic autoimmune diseases (P = 0.0003). A significant high prevalence of coeliac disease and Addison disease was found (P = 0.034 and P = 0.049, respectively). In patients with coeliac disease, the articular manifestations were more frequent (21.21%) (P = 0.001) and the risk to develop joint involvement was 2.96., Conclusion: Although we found an articular involvement in about one-third of thyroiditis patients, the prevalence of inflammatory arthropathy was only 8.33%. The prevalence of other coexisting autoimmune disorders was 34.26% with a significant prevalence of coeliac disease (7.41%). Thyroiditis patients with coeliac disease have an articular involvement more frequently than those without. In these patients, we have found a high risk of developing arthritis than patients with only thyroiditis, suggesting cumulative autoimmune effects in the developing articular involvement., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Children with type 1 diabetes (T1D) are not included in guidelines regarding diagnosis criteria for celiac disease (CD) without a diagnostic biopsy, due to lack of data. We explored whether tissue transglutaminase antibodies (anti-tTG) that were ≥ 10 times the upper limit of normal (10× ULN) predicted CD in T1D., Methods: Data from the Swedish prospective Better Diabetes Diagnosis study was used, and 2035 children and adolescents with T1D diagnosed between 2005-2010 were included. Of these, 32 had been diagnosed with CD before T1D. The children without CD were repeatedly screened for CD using anti-tTG antibodies of immunoglobulin type A. In addition, their human leukocyte antigen (HLA) were genotyped. All children with positive anti-tTG were advised to undergo biopsy. Biopsies were performed on 119 children and graded using the Marsh-Oberhüber classification., Results: All of the 60 children with anti-tTG ≥10x ULN had CD verified by biopsies. The degree of mucosal damage correlated with anti-tTG levels. Among 2003 screened children, 6.9% had positive anti-tTG and 5.6% were confirmed CD. The overall CD prevalence, when including the 32 children with CD before T1D, was 7.0% (145/2035). All but one of the children diagnosed with CD had HLA-DQ2 and/or DQ8., Conclusions: As all screened children and adolescents with T1D with tissue transglutaminase antibodies above 10 times the positive value 10x ULN had CD, we propose that the guidelines for diagnosing CD in screened children, when biopsies can be omitted, should also apply to children and adolescents with T1D as a noninvasive method., (© 2020 The Authors. Pediatric Diabetes published by John Wiley & Sons Ltd.)

Objectives: To evaluate the diagnostic and predictive contribution of autoantibodies screening in patients with primary immunodeficiencies (PIDs)., Methods: In the present study, PID patients and healthy controls have been screened for 54 different autoantibodies. The results of autoantibodies screening in PID patients were correlated to the presence of autoimmune diseases., Results: A total of 299 PID patients were included in this study with a predominance of antibody deficiencies (27.8%) followed by immunodeficiencies affecting cellular and humoral immunity (26.1%) and complement deficiencies (22.7%). Autoimmune manifestations were present in 82 (27.4%) patients. Autoimmune cytopenia (10.4%) was the most common autoimmune disease followed by gastrointestinal disorders (10.0%), rheumatologic diseases (3.7%), and endocrine disorders (3.3%). Autoantibodies were found in 32.4% of PID patients and 15.8% of healthy controls ( P < 0.0005). Anti-nuclear antibodies (ANA) (10.0%), transglutaminase antibody (TGA) (8.4%), RBC antibodies (6.7%), anti-smooth muscle antibody (ASMA) (5.4%), and ASCA (5.0%) were the most common autoantibodies in our series. Sixty-seven out of the 82 patients with autoimmune manifestations (81.7%) were positive for one or more autoantibodies. Eleven out of the 14 patients (78.6%) with immune thrombocytopenia had positive platelet-bound IgM. The frequencies of ASCA and ANCA among patients with IBD were 47.4% and 21.0% respectively. All patients with celiac disease had TGA-IgA, while six out of the 11 patients with rheumatologic diseases had ANA (54.5%). Almost one third of patients (30/97) with positive autoantibodies had no autoimmune manifestations. ANA, rheumatoid factor, ASMA, anti-phospholipid antibodies and ANCA were often detected while specific AID was absent. Despite the low positive predictive value of TGA-IgA and ASCA for celiac disease and inflammatory bowel disease respectively, screening for these antibodies identified undiagnosed disease in four patients with positive TGA-IgA and two others with positive ASCA., Conclusion: The present study provides valuable information about the frequency and the diagnostic/predictive value of a large panel of autoantibodies in PIDs. Given the frequent association of some AIDs with certain PIDs, screening for corresponding autoantibodies would be recommended. However, positivity for autoantibodies should be interpreted with caution in patients with PIDs due to their low positive predictive value., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Tahiat, Yagoubi, Ladj, Belbouab, Aggoune, Atek, Bouziane, Melzi, Boubidi, Drali, Bendahmane, Iguerguesdaoune, Taguemount, Soufane, Oukil, Ketfi, Messaoudi, Boukhenfouf, Ifri, Bencharif Madani, Belhadj, Benhala, Khiari, Cherif, Smati, Arada, Zeroual, Bouzerar, Ibsaine, Maouche, Boukari and Djenouhat.)

Introduction : Celiac disease is characterized by an abnormal immune activation driven by the ingestion of gluten from wheat, barley, and rye. Gluten-specific CD4 + T cells play an important role in disease pathogenesis and are detectable among peripheral blood mononuclear cells (PBMCs). Areas covered : This review summarizes the use of celiac disease patient PBMCs in clinical applications focusing on their exploitation in the development of diagnostic approaches and novel drugs to replace or complement gluten-free diet. Expert opinion : The most used PBMC-based methods applied in celiac disease research include ELISpot and HLA-DQ:gluten tetramer technology. ELISpot has been utilized particularly in research aiming to develop a celiac disease vaccine and in studies addressing the toxicity of different grains in celiac disease. HLA-DQ:gluten tetramer technology on the other hand initially focused on improving current diagnostics but in combination with additional markers it is also a useful outcome measure in clinical trials to monitor the efficacy of drug candidates. In addition, the technology serves well in the more detailed characterization of celiac disease-specific T cells, thereby possibly revealing novel therapeutic targets. Future studies may also reveal clinical applications for PBMC microRNAs and/or dendritic cells or monocytes present among PBMCs.

Objective: The prevalence of celiac disease (CD) varies between 1% and 10% in patients with type 1 diabetes mellitus (T1DM). This study aimed to determine the frequency of spontaneous recovery of celiac serology and the biopsy-proven CD (BPCD) frequency in patients with T1DM., Methods: The data of 668 patients with available celiac serology tests from a total of 779 patients who were followed for the last 10 years with the diagnosis of T1DM were retrospectively evaluated., Results: Positive serology was detected in 103 out of 668 (15.4%) patients. There was spontaneous normalization in 24 (23.3%), fluctuation in 11 (10.7%) and permanently positive serology in 68 (66%). In 46 out of 53 (86.8%) patients with positive serology and biopsy, CD diagnosis was confirmed by biopsy (BPCD). The frequency of BPCD was 6.9%, and the serology in 76.1% was positive at the time of diagnosis of T1DM. The weight, height and body mass index-standard deviation score at diagnosis were lower in patients with BPCD compared to the group without CD. An anti-tissue transglutaminase-IgA (anti-TTG-IgA) level of 11.8 times the upper limit of normal was the most sensitive (93%) and specific (90%) cut-off for BPCD (area under the curve: 0.95; 95% confidence interval: 0.912-1; p<0.001)., Conclusion: In our cohort, the frequency of positive serology for CD was 15.4%, while the rate of BPCD was 6.9%. The majority (97.8%) of cases were diagnosed within the first five years of T1DM. In 23.3% of cases, positive anti-TTG-IgA spontaneously resolved without a gluten-free diet (GFD). Therefore, serological follow-up instead of immediate duodenal biopsy or GFD therapy, particularly for patients with asymptomatic and mild anti-TTG IgA level, is warranted.

Altered circulating levels of free fatty acids (FFAs), namely short chain fatty acids (SCFAs), medium chain fatty acids (MCFAs), and long chain fatty acids (LCFAs), are associated with metabolic, gastrointestinal, and malignant diseases. Hence, we compared the serum FFA profile of patients with celiac disease (CD), adenomatous polyposis (AP), and colorectal cancer (CRC) to healthy controls (HC). We enrolled 44 patients (19 CRC, 9 AP, 16 CD) and 16 HC. We performed a quantitative FFA evaluation with the gas chromatography-mass spectrometry method (GC-MS), and we performed Dirichlet-multinomial regression in order to highlight disease-specific FFA signature. HC showed a different composition of FFAs than CRC, AP, and CD patients. Furthermore, the partial least squares discriminant analysis (PLS-DA) confirmed perfect overlap between the CRC and AP patients and separation of HC from the diseased groups. The Dirichlet-multinomial regression identified only strong positive association between CD and butyric acid. Moreover, CD patients showed significant interactions with age, BMI, and gender. In addition, among patients with the same age and BMI, being male compared to being female implies a decrease of the CD effect on the (log) prevalence of butyric acid in FFA composition. Our data support GC-MS as a suitable method for the concurrent analysis of circulating SCFAs, MCFAs, and LCFAs in different gastrointestinal diseases. Furthermore, and notably, we suggest for the first time that butyric acid could represent a potential biomarker for CD screening.

Celiac disease (CD) is a chronic immune-mediated enteropathy triggered by exposure to dietary gluten in genetically predisposed individuals. In contrast, irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder affecting the large intestine, without an autoimmune component. Here, we evaluated the prevalence of IgA and IgG antibodies to maize zeins (AZA) in patients with CD and IBS. Using an in-house ELISA assay, the IgA and IgG anti-zein antibodies in the serum of 37 newly diagnosed CD (16 biopsy proved and 21 serological diagnosis) and 375 IBS patients or 302 healthy control (HC) subjects were measured. Elevated levels of IgA AZA were found in CD patients compared with IBS patients ( p < 0.01) and HC ( p < 0.05). CD patients had the highest prevalence (35.1%), followed by IBS (4.3%) and HCs (2.3%) ( p < 0.0001). IgG AZA antibodies were not found in any CD patients, IBS patients, or HC subjects. A significant positive correlation was found between IgA AZA with IgA anti-gliadin (AGA, r = 0.34, p < 0.01) and IgA anti-deaminated gliadin peptides (DGP, r = 0.42, p < 0.001) in the celiac disease group. Taken together, our results show for the first time a higher prevalence of AZA IgA antibodies in newly diagnosed CD patients than in IBS patients, confirming a biased immune response to other gliadin-related prolamins such as maize zeins in genetically susceptible individuals.

Background: The serological screening for celiac disease (CD) is currently based on the detection of anti-transglutaminase (tTG) IgA antibodies, subsequently confirmed by positive endomysial antibodies (EMA). When an anti-tTG IgA positive/EMA IgA negative result occurs, it can be due either to the lower sensitivity of the EMA test or to the lower specificity of the anti-tTG test. This study aimed at verifying how variation in analytical specificity among different anti-tTG methods could account for this discrepancy., Methods: A total of 130 consecutive anti-tTG IgA positive/EMA negative samples were collected from the local screening routine and tested using five anti-tTG IgA commercial assays: two chemiluminescence methods, one fluoroimmunoenzymatic method, one immunoenzymatic method and one multiplex flow immunoassay method., Results: Twenty three/130 (17.7%) patients were diagnosed with CD. In the other 107 cases a diagnosis of CD was not confirmed. The overall agreement among the five anti-tTG methods ranged from 28.5% to 77.7%. CD condition was more likely linked to the positivity of more than one anti-tTG IgA assay (monopositive = 2.5%, positive with ≥ three methods = 29.5%; p = 0.0004), but it was not related to anti-tTG IgA antibody levels (either positive or borderline; p = 0.5)., Conclusions: Patients with positive anti-tTG/negative EMA have a low probability of being affected by CD. Given the high variability among methods to measure anti-tTG IgA antibodies, anti-tTG-positive/EMA-negative result must be considered with extreme caution. It is advisable that the laboratory report comments on any discordant results, suggesting to consider the data in the proper clinical context and to refer the patient to a CD reference center for prolonged follow up., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background & Aims: Gluten challenge is used to diagnose celiac disease (CeD) and for clinical research. Sustained gluten exposure reliably induces histologic changes but is burdensome. We investigated the relative abilities of multiple biomarkers to assess disease activity induced by 2 gluten doses, and aimed to identify biomarkers to supplement or replace histology., Methods: In this randomized, double-blind, 2-dose gluten-challenge trial conducted in 2 US centers (Boston, MA), 14 adults with biopsy-proven CeD were randomized to 3 g or 10 g gluten/d for 14 days. The study was powered to detect changes in villous height to crypt depth, and stopped at planned interim analysis on reaching this end point. Additional end points included gluten-specific cluster of differentiation (CD)4 T-cell analysis with HLA-DQ2-gluten tetramers and enzyme-linked immune absorbent spot, gut-homing CD8 T cells, interleukin-2, symptoms, video capsule endoscopy, intraepithelial leukocytes, and tissue multiplex immunofluorescence., Results: All assessments showed changes with gluten challenge. However, time to maximal change, change magnitude, and gluten dose-response relationship varied. Villous height to crypt depth, video capsule endoscopy enteropathy score, enzyme-linked immune absorbent spot, gut-homing CD8 T cells, intraepithelial leukocyte counts, and HLA-DQ2-restricted gluten-specific CD4 T cells showed significant changes from baseline at 10 g gluten only; symptoms were significant at 3 g. Symptoms and plasma interleukin-2 levels increased significantly or near significantly at both doses. Interleukin-2 appeared to be the earliest, most sensitive marker of acute gluten exposure., Conclusions: Modern biomarkers are sensitive and responsive to gluten exposure, potentially allowing less invasive, lower-dose, shorter-duration gluten ingestion. This work provides a preliminary framework for rational design of gluten challenge for CeD research. ClinicalTrials.gov number, NCT03409796., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the vitamin D status of children with a new diagnosis of celiac disease compared with healthy controls., Study Design: This was a case-control study. Cases were consecutive children with newly diagnosed celiac disease. Controls were healthy children matched for age, sex, ethnicity, and month of blood testing. Plasma 25-hydroxyvitamin D (25-OHD) was measured as the index of vitamin D nutritional status. The Student t test was used for comparisons. Differences in frequencies were evaluated with the χ 2 test. Associations between variables were estimated by calculating Pearson correlation coefficients., Results: There were 131 children with celiac disease enrolled (62% females; mean age 8.1 ± 1.1 years). The control group included 131 healthy children (62% females; mean age 8.2 ± 1.2). All were of European origin. Plasma 25-OHD levels were significantly lower in patients than in controls (25.3 ± 8.0 and 31.6 ± 13.7 ng/mL; P < .0001). The percentage of children with vitamin D deficiency (<20 ng/mL) was significantly higher in children with celiac diseaseas compared with controls (31% vs 12%; P < .0001). The concentration of 25-OHD was significantly lower in patients than in controls during summer (P < .01) and autumn (P < .0001)., Conclusions: In this case-control study, at diagnosis, children with celiac disease showed lower levels of plasma 25-OHD compared with healthy subjects. Vitamin D status should be checked at diagnosis of celiac disease, particularly during summer and fall months., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The advent of time-of-flight mass cytometry (CyTOF) has enabled high dimensional and unbiased examination of the immune system to simultaneous interrogate a multitude of parameters and gain a better understanding of immunologic data from clinical trial samples. Here we describe the development and validation of a 33-marker mass cytometry workflow for measuring gastrointestinal (GI) trafficking peripheral blood mononuclear cells (PBMCs) in patients with celiac disease (CeD). This panel builds upon identification of well-characterized immune cells and expands to include markers modulated in response to gluten challenge in patients with CeD. The CeD panel was optimized and validated according to accepted industry practice for validation of flow cytometry assays and builds upon established sample processing workflows for mass cytometry studies. Several critical parameters were evaluated during the assay development phase of this study including optimization of the sample processing steps, antibody specificity, and ensuring the panel as a whole performed to expectation. The panel was then validated using a fit-for-purpose approach tailored to the intended use of the data in the clinical trial. Validation included assessment of analytical parameters essential to understanding the reliability and robustness of the CeD panel such as intra-assay precision, inter-assay precision, inter-operator precision and sample processing stability. Together, this validated mass cytometry workstream provides robust and reproducible high-dimensional analysis of human peripheral blood immune cells to characterize patient samples from clinical trials., (© 2021 International Clinical Cytometry Society.)

A lifelong gluten-free diet (GFD) is the only current treatment for celiac disease (CD), but strict compliance is complicated. Duodenal biopsies are the "gold standard" method for diagnosing CD, but they are not generally recommended for disease monitoring. We evaluated the sensitivity and specificity of fecal gluten immunogenic peptides (GIPs) to detect duodenal lesions in CD patients on a GFD and compared them with serum anti-tissue transglutaminase (tTG) IgA antibodies. A prospective study was conducted at two tertiary centers in Spain on a consecutive series of adolescents and adults with CD who maintained a long-lasting GFD. Adherence to a GFD and health-related quality of life were scored with validated questionnaires. Mucosal damage graded according to the Marsh-Oberhüber classification (Marsh 1/2/3) was used as the reference standard. Of the 97 patients included, 27 presented duodenal mucosal damage and 70 had normal biopsies (Marsh 0). The sensitivity (33%) and specificity (81%) of GIPs were similar to those provided by the two assays used to measure anti-tTG antibodies. Scores in questionnaires showed no association with GIP, but an association between GIPs and patients' self-reported gluten consumption was found ( p = 0.003). GIP displayed low sensitivity but acceptable specificity for the detection of mucosal damage in CD.

The clinical phenotype of celiac disease varies considerably among patients and the dosage of HLA-DQ2.5 alleles has been suggested to be a contributing factor. We investigated whether HLA-DQ2.5 allele dosage is associated with distinct clinical parameters at the time of diagnosis and with patients' response to a gluten-free diet. The final cohort included 605 carefully phenotyped non-related Finnish celiac disease patients grouped as having 0, 1 or 2 copies of HLA-DQ2.5. Clinical data at the time of diagnosis and during gluten-free diet were collected systematically from medical records and supplementary interviews. An increasing HLA-DQ2.5 dose effect was detected for celiac disease antibody positivity at diagnosis ( p = 0.021) and for the presence of any first-degree relatives with celiac disease ( p = 0.011 and p = 0.031, respectively). Instead, DQ2.5-negative patients were suffering most often from classical symptoms at diagnosis ( p = 0.007 between HLA groups). In addition, during follow-up they were most often symptomatic despite a gluten-free diet ( p = 0.002 between groups). Our results thus suggest that increasing HLA-DQ2.5 dose only has a minor effect on the clinical picture of celiac disease. However, HLA-DQ2.5-negative patients should not be overlooked in clinical practice and particular attention should be paid to this patient group during gluten-free diet.

Celiac disease (CD) is an autoimmune enteropathy associated with alterations of metabolism. Metabolomics studies, although limited, showed changes in choline, choline-derived lipids, and methionine concentrations, which could be ascribed to alterations in one-carbon metabolism. To date, no targeted metabolomics analysis investigating differences in the plasma choline/methionine metabolome of CD subjects are reported. This work is a targeted metabolomic study that analyzes 37 metabolites of the one-carbon metabolism in 17 children with CD, treated with a gluten-free diet and 17 healthy control siblings, in order to establish the potential defects in this metabolic network. Our results demonstrate the persistence of defects in the transsulfuration pathway of CD subjects, despite dietary treatment, while choline metabolism, methionine cycle, and folate cycle seem to be reversed and preserved to healthy levels. These findings describe for the first time, a metabolic defect in one-carbon metabolism which could have profound implications in the physiopathology and treatment of CD.

Objective: To determine whether children in the community with functional constipation have increased prevalence of celiac disease., Study Design: Between April 4, 2015, and April 25, 2017, we enrolled 1809 children from 5 schools in Colombia and screened them for functional gastrointestinal disorders (FGIDs), including functional constipation, using questionnaires recommended in the Rome III/IV criteria. We matched children with functional constipation with healthy controls without a FGID and tested them for celiac disease with tissue transglutaminase (tTG)-Immunoglobulin A (IgA) and total IgA screening. In those who tested positive for tTG-IgA, we performed HLA genotyping and endoscopy to obtain 4 duodenal biopsy specimens for classification of celiac disease using the Marsh criteria. Analysis of statistical significance between groups of children with and without functional constipation was done using a 2-tailed Fisher exact test., Results: Patients diagnosed with functional constipation (n = 203) were matched with 419 healthy controls without FGIDs. The overall prevalence of celiac disease in the entire cohort was 0.6%. Of those with functional constipation, 1 (0.5%) was diagnosed with celiac disease, and 3 (0.7%) of the control patients without FGIDs had celiac disease (P = .743)., Conclusions: The prevalence of celiac disease in our cohort was similar to worldwide estimates. The prevalence of celiac disease in schoolchildren with functional constipation in Colombia is similar to those without FGIDs. Thus, routine testing of schoolchildren with functional constipation for celiac disease is not indicated., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Aim: To investigate the role of endothelial PV-1 in patients with untreated celiac disease (CD)-associated liver injury. Materials & methods: PV-1 and PV-1 mRNA were measured in intestinal biopsies from untreated CD patients with elevated or normal alanine transaminase levels, controls, patients with inflammatory bowel disease and patients with toxic liver injury. Circulating PV-1 levels were also evaluated. Results: Circulating PV-1 levels were significantly increased in the serum of patients with CD-associated liver injury and reverted to normal following a gluten-free diet. Mucosal PV-1 and PV-1 mRNA were no different in patients with CD-associated liver injury. Conclusion: Serum but not mucosal PV-1 represents a marker of gluten-dependent liver injury and response to a gluten-free diet in patients with untreated CD.

Objective: Non-coeliac gluten sensitivity (NCGS) is characterised by intestinal and extraintestinal symptoms related to the ingestion of gluten-containing foods, in the absence of coeliac disease (CD) and wheat allergy. No biomarkers are available to diagnose NCGS and the gold standard double-blind placebo-controlled gluten challenge is clinically impractical. The aim of our work was to investigate the role of serum zonulin as a diagnostic biomarker of NCGS and to develop a diagnostic algorithm., Design: In a multicentre study, we enrolled 86 patients with either self-reported or double-blind confirmed NCGS, 59 patients with diarrhoea-predominant IBS (IBS-D), 15 patients with CD and 25 asymptomatic controls (AC). Zonulin serum levels were assessed and the associated diagnostic power calculated. Clinical and symptomatic data were recorded. The effect of diet on zonulin levels was evaluated in a subgroup of patients with NCGS., Results: Compared with ACs, the NCGS, irrespective of modality of diagnosis, and patients with CD had significantly increased levels of zonulin, as did both NCGS and patients with CD compared with participants with IBS-D. Self-reported NCGS showed increased zonulin levels compared with double-blind confirmed and not-confirmed NCGS. Six-month wheat avoidance significantly reduced zonulin levels only in HLA-DQ2/8-positive participants with NCGS. The diagnostic accuracy of zonulin levels in distinguishing NCGS from IBS-D was 81%. After exclusion of CD, a diagnostic algorithm combining zonulin levels, symptoms and gender improved the accuracy to 89%., Conclusion: Zonulin can be considered a diagnostic biomarker in NCGS and combined with demographic and clinical data differentiates NCGS from IBS-D with high accuracy. Wheat withdrawal was associated with a reduction in zonulin levels only in NCGS carrying HLA genotype., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)