Anti-Saccharomyces cerevisiae antibodies and coeliac disease

Causal association between celiac disease and inflammatory bowel disease: A two-sample bidirectional Mendelian randomization study

Background

An epidemiological link between celiac disease (CeD) and inflammatory bowel disease (IBD) has been well established recently. In this study, Mendelian randomization (MR) analysis was performed employing pooled data of publicly available genome-wide association studies (GWAS) to determine the causal relationship between CeD and IBD, encompassing ulcerative colitis (UC) and Crohn's disease (CD).

Methods

Dataset of CeD was acquired from GWAS for 12,041 cases and 12,228 controls. A GWAS of more than 86,000 patients and controls was used to identify genetic variations underlying IBD. MR analyses were performed with an inverse-variance-weighted approach, an MR-Egger regression, a weighted-mode approach, a weighted-median method, and sensitivity analyses of MR pleiotropy residual sum and outlie (MR-PRESSO).

Results

MR demonstrated that genetic predisposition to CeD was linked to a augmented risk of IBD (OR: 1.1408; 95% CI: 1.0614-1.2261; P = 0.0003). In the analysis of the two IBD subtypes, genetic predisposition to CeD was also linked to increased risks of UC (OR: 1.1646; 95% CI: 1.0614-1.2779; P = 0.0012) and CD (OR: 1.1865; 95% CI: 1.0948-1.2859; P = 3.07E-05). Reverse MR analysis results revealed that genetic susceptibility to IBD and CD was correlated with an augmented risk of CeD. However, there was no genetic correlation between UC and CeD. All of the above results were validated with other GWAS databases.

Conclusion

There is a bidirectional causal relationship of CeD with IBD and CD. However, UC only augments the risk of developing CeD.

Patients With Inflammatory Bowel Disease on Treatment Have Lower Rates of Celiac Disease

BACKGROUND

The association between celiac disease and inflammatory bowel disease (IBD) has been studied; however, the impact of IBD therapy on celiac disease is not known. Using a large database, we sought to describe the association of celiac disease and IBD and the impact of IBD treatment.

METHODS

We queried a large multicenter database (Explorys Inc.), an electronic health record data aggregate from 26 American health care systems. We identified a cohort of patients with celiac disease and IBD between 1999 and 2020 and conducted a statistical analysis using a multivariate model.

RESULTS

Of the 72,965,940 individuals in the database, 133,400 had celiac disease (0.18%), 191,570 (0.26%) had ulcerative colitis (UC), and 230,670 (0.32%) had Crohn disease (CD). Patients with IBD were more likely to have a diagnosis of celiac disease (odds ratio [OR], 13.680), with a greater association with CD. Treated patients with UC and with CD, respectively, had a lower risk association with celiac disease compared to those not undergoing IBD treatment, specifically corticosteroids (OR, 0.407 and 0.585), 5-aminosalicylates (OR, 0.124 and 0.127), immunomodulators (OR, 0.385 and 0.425), and anti-tumor necrosis factor drugs (OR, 0.215 and 0.242). There was no lower risk association in the vedolizumab group, but there was a higher risk association among the ustekinumab group.

CONCLUSIONS

In this large dataset, we showed a bidirectional association between celiac disease and IBD that was stronger with CD. Patients with IBD treated using corticosteroids, 5-aminosalicylates, immunomodulators, or anti-tumor necrosis factor drugs had a lower association with celiac disease. Additional studies are required to determine the underlying mechanisms for IBD therapy-related modification of celiac disease incidence.

Prevalance of Celiac Disease in Patients with Inflammatory Bowel Disease in Turkish Population

BACKGROUND

Celiac disease (CD) and inflammatory bowel disease (IBD) involve inflammation of the gastrointestinal lumen, which environmental, genetic, and immunological factors have a role in their pathogenesis. The prevalence of celiac disease in IBD ranges from 0% to 14%. In this study, our aim was to determine the prevalence of CD in IBD patients followed by us who are attending the hospital or outpatient clinic over a period of time of seven years.

METHODS

Seven hundred and fifty nine patients (425 M, 334 F, mean age: 46.75, 396 ulcerative colitis (UC), 363 Crohn's disease (CrD)) diagnosed and followed up for IBD between January 2009 and July 2016 were evaluated retrospectively, and clinical, demographic, laboratory, and endoscopic data were collected.

RESULTS

CD was investigated in 79 (%10.4) inflammatory bowel disease patients according to symptoms, and in 5.06% (n = 4) of them, we diagnosed CD. The most common indication for investigating for CD was iron deficiency anemia unreponsive to iron supplementation.

CONCLUSIONS

We did not find an increased prevalance of celiac disease in Turkish IBD patients in this study. In the presence of refractory iron deficiency anemia without any other cause in IBD patients, investigations for celiac disease should be considered.

Early microbial markers of celiac disease

BACKGROUND AND GOALS

Seroreactivity against the Saccharomyces cerevisiae (ASCA), Pseudomonas fluorescens-associated sequence (I2), and Bacteroides caccae TonB-linked outer membrane protein (OmpW) has been detected in celiac disease patients with small-bowel mucosal atrophy. Levels of these antibodies decrease during a gluten-free diet, but their functions and time of appearance in celiac disease are not known. We aimed to search for evidence of possible microbial targets of the immune responses in the early-stage celiac disease patients who showed normal small-bowel mucosal architecture at the time of the first investigations, but later on a gluten-containing diet developed mucosal atrophy.

MATERIALS AND METHODS

Forty-four cases with proven early-stage celiac disease and normal mucosal morphology were enrolled. Patients' sera were tested for celiac disease antibodies against tissue transglutaminase (tTG-ab), endomysium, and for microbial antibodies against I2, OmpW, and ASCA IgG and IgA isotypes in both at the time of diagnosis and while on a gluten-free diet.

RESULTS

Thirty-four (77%) of 44 patients with early-stage celiac disease had elevated serum antibodies to one or more of the antibodies ASCA, I2, and OmpW. Furthermore, 5 of 6 cases negative for both tTG-ab and endomysium showed positivity for the microbial markers. Seroreactivity to ASCA IgA, ASCA IgG, and OmpW decreased significantly during gluten-free diet.

CONCLUSIONS

Seroreactivity to different microbial antigens is evident already in patients with early-stage celiac disease. ASCA antibodies seem to be gluten-dependent. The results indicate that the microbial targets might have a role in the early development of celiac disease.

Nutritional influences in selected gastrointestinal diseases

Nutritional factors, as sources of luminal antigens, have been thought to be important factors in the immunopathogenesis of numerous gastrointestinal diseases. In some diseases, the role of the nutritional component is causal in the susceptible host. Such diseases include celiac disease, a common heritable chronic inflammatory condition of the small intestine induced by dietary wheat, rye and barley, in susceptible individuals. Specific HLA-DQ2 and HLA-DQ8 risk alleles are necessary, but not sufficient, for disease development. The well-defined role of HLA-DQ heterodimers encoded by these alleles is to present cereal peptides to CD4+ T cells, activating an inflammatory immune response in the intestine. Genome-wide association studies have been performed which identified the IL2-IL21 risk locus and other genes with immune functions and key roles in thymic T-cell selection. Another example for this group is Wilson's disease, an autosomal recessive disorder of copper metabolism caused by mutation of the ATP7B gene, resulting in a defect of biliary copper excretion and toxic accumulation in the body, especially in the liver, brain and cornea, resulting in hepatic and/or neurological symptoms. In other diseases, however, the association is less well established. In such endeavor, epidemiological observations may become a valuable part of the overall investigations aimed at identifying dietary factors, which are involved in the initiation and perpetuation of the specific disease. As an example, relationships between nutrition and colorectal cancer have been hypothesized early on (e.g. folate, calcium, vitamin D, red meat). Similarly, intake of certain diet constituents like fat, refined sugar, fruits, vegetables and fiber was reported to be associated with the expression of inflammatory bowel diseases. In addition, in children with active Crohn's disease, enteral nutrition was found to be equally effective as corticosteroids in induction of remission, with mucosal healing induced by downregulation of mucosal pro-inflammatory cytokine profiles in both the ileum and the colon after enteral nutrition. However, the particular effect of the consumption of each type of food remains questionable in most cases, at least in part because of insufficient data and serious methodological limitations (e.g. recall bias, heterogeneity between collected data, lack of correction for covariates, difficulties in double blinding).

Prevalence of celiac disease in inflammatory bowel diseases: An IG-IBD multicentre study

BACKGROUND

An association has been described in case reports between celiac disease and inflammatory bowel diseases. The aim of the present study is to assess the prevalence of celiac disease in a large series of Italian patients with inflammatory bowel disease.

METHODS

The Italian Group for Inflammatory Bowel Disease conducted a multicentre study between January 2002 and December 2004, in which 22 gastroenterology centres in Italy enrolled 1711 consecutive outpatients with inflammatory bowel disease. 860 (50.2%) had Crohn's disease (415 females, mean age 40, range 18-75), 791 (46.2%) had ulcerative colitis (371 females, mean age 40, range 18-80), and 60 (3.5%) had indeterminate colitis (27 females, mean age 40, range 18-78). All patients underwent serological testing for anti-endomysial antibodies and anti-tissue transglutaminase antibodies; if positive upper GI endoscopy with duodenal biopsy was performed.

RESULTS

Nine of the 1711 patients (0.5%) had serological and histological findings compatible with the diagnosis of celiac disease; six of them had ulcerative colitis and three had Crohn's disease.

CONCLUSIONS

Overall we found a lower risk of celiac disease in our cohort of inflammatory bowel disease patients than in the general population; prevalence of celiac disease was higher in patients with ulcerative colitis than in those with Crohn's disease.

Anti-microbial antibodies in celiac disease: trick or treat?

AIM

To determine the prevalence of a new set of anti-glycan and anti-outer membrane protein (anti-OMP) antibodies in a Hungarian cohort of adult Celiac disease (CD) patients.

METHODS

190 consecutive CD patients [M/F: 71/119, age:39.9 (SD:14.1) years], 100 healthy, and 48 gastrointestinal controls were tested for glycan anti-Saccharomyces cerevisiae (gASCA), anti-laminaribioside (ALCA), anti-chitobioside, anti-mannobioside, anti-OMP antibodies and major NOD2/CARD15 mutations. Thirty out of 82 CD patients enrolled at the time of diagnosis were re-evaluated for the same antibodies after longstanding gluten-free diet (GFD).

RESULTS

65.9% of the CD patients were positive for at least one of the tested antibodies at the time of the diagnosis. Except anti-OMP and ALCA, anti-microbial antibodies were exclusively seen in untreated CD; however, the overall sensitivity was low. Any glycan positivity (LR+: 3.13; 95% CI: 2.08-4.73) was associated with an increased likelihood ratio for diagnosing CD. Significant correlation was found between the levels of anti-glycan and anti-endomysial or anti-transglutaminase antibodies. Anti-glycan positivity was lost after longstanding GFD. Anti-glycan antibody titers were associated with symptoms at presentation, but not the presence of NOD2/CARD15 mutations. Patients with severe malabsorption more frequently had multiple antibodies at diagnosis (P = 0.019).

CONCLUSION

The presence of anti-glycan antibodies in CD seems to be secondary to the impaired small bowel mucosa which can lead to increased antigen presentation. Furthermore, anti-glycan positivity may be considered an additional marker of CD and dietary adherence.

Anti-Saccharomyces cerevisiae antibodies in primary biliary cirrhosis

AIM

The aim of this study was to evaluate, retrospectively, the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with primary biliary cirrhosis (PBC).

METHODS

ASCA, IgG, and IgA, were determined by ELISA in sera of 95 PBC patients; 80 healthy blood donors served as controls.

RESULTS

The frequency of ASCA (IgG or IgA) was significantly higher in PBC patients than in the control group (24.2% vs 3.7%, P = 0.0001). The frequency of ASCA IgG and ASCA IgA in PBC patients was also significantly higher than that found in the control group (18.9% vs 2.5%, P = 0.0006 and 11.6% vs 1.2%, P = 0.007, respectively). Six patients out of 95 (6.3%) had both ASCA IgG and ASCA IgA; in contrast, none of the control group had both isotypes (P = 0.02). There was no correlation between ASCA levels and mitochondrial autoantibodies (AMA) titres in PBC patients.

CONCLUSION

We conclude that ASCA are common in patients with PBC.

Anti-Saccharomyces cerevisiae antibodies in coeliac disease

OBJECTIVE

To evaluate, retrospectively, the frequency of anti-Saccharomyces cerevisiae antibodies (ASCA) in patients with coeliac disease.

MATERIAL AND METHODS

ASCA, IgG and IgA were determined by ELISA in sera of 238 coeliac patients. The patients were divided into three groups: group I - 125 untreated patients; group II - 42 patients under a strict gluten-free diet (GFD); and group III - 71 patients who did not comply with a GFD. Sera of 80 healthy blood donors served as controls.

RESULTS

The frequency of ASCA (IgG or IgA) was significantly higher in untreated coeliac patients than in the control group (27.2% versus 3.7%, p=10(-5)). In 238 coeliac patients, the frequency of ASCA was significantly higher in adults than in children (35.4% versus 21.1%, p=0.01). In group III, the frequency of ASCA was significantly higher in adults than in children (60% versus 26.1%, p=0.004). In 238 coeliac patients, ASCA IgG were significantly more frequent than ASCA IgA in both children (19% versus 6.3%, p=0.001) and adults (33.3% versus 12.5%, p=5.10(-4)). In children, ASCA IgG were negative in group II and positive in 20% of group I (p=0.01). In adults, the frequency of ASCA IgG was also significantly lower in group II than in group I (9.5% versus 34%, p=0.03).

CONCLUSIONS

A high frequency of ASCA has been found in coeliac patients. The frequency of ASCA was not statistically different between patients with successful adherence to GFD and healthy controls.