Prevalence of Serologically Defined Celiac Disease in Patients With Irritable Bowel Syndrome in Asia: A Multicountry Hospital‐Based Study

Celiac disease (CeD) is not adequately recognized in Asia. We aimed to assess the prevalence of CeD in patients with irritable bowel syndrome (IBS) in six Asian countries and identify high-risk groups meriting screening. Patients with IBS (Rome III) were recruited from Japan, Thailand, Indonesia, Malaysia, Singapore, and India. A two-step noninvasive strategy was used [positive IgA anti-tissue transglutaminase antibody (IgA anti-tTG-Ab) followed by confirmation with IgA deamidated gliadin-peptide antibodies (anti-DGP-Ab)]. Consenting patients with positive serology also underwent duodenal biopsies. Positivity for both IgA-anti-tTG-Ab and IgA-anti-DGP-Ab was labeled as serologically defined CeD. Important predictors of CeD were identified using the Boruta algorithm, and a nomogram for predicting CeD was constructed. 2546 patients with IBS were evaluated across 6 countries. Overall prevalence serologically defined CeD (positive for both IgA anti-tTG Ab and IgA anti-DGP antibodies) was 2.75% (n = 70; 95% CI, 2.11%-3.39%). Prevalence was highest in Malaysia (3.8%), India (3.75%), and Indonesia (3.61%) and lowest in Japan (0.1%). Duodenal biopsies were performed in 20 patients, and 14 of them showed villous abnormalities (modified Marsh grade 2 or more). Among IgA anti-tTG-Ab-positive patients (n = 204; 8.01% 95% CI, 6.96%-9.07%), 18 (0.71%), 21 (0.82%), and 165 (6.48%) exhibited anti-tTG-Ab titer more than 10-fold, 6-10-fold, and 1-5-fold above the upper limit of normal. We propose a nomogram to predict the risk of CeD in Asian patients with IBS based on country, hemoglobin, age, sex, and diarrhea. Overall prevalence of serologically defined CeD in Asian patients with IBS is 2.75% but differs across patient profiles. This study suggests the need for better awareness and further studies on the prevalence of CeD across Asia.