Prevalence of coeliac disease in Northwest China: heterogeneity across Northern Silk road ethnic populations

Abstract

Background Epidemiological data of coeliac disease are lacking from the central Asian region. Aims To verify the occurrence of coeliac disease amongst four major ethnic groups of Xinjiang Uyghur Autonomus Region, China. Methods 2277 in‐patients with gastrointestinal symptoms (1391 Han, 608 Uyghur, 146 Kazakh and 132 Hui; mean age: 54 ± 12.8 years) were included. Total IgA, anti‐deamidated gliadin peptide (DGP)‐IgG, and anti‐tissue transglutaminase (anti‐tTG)‐IgA were analysed. All antibody‐positive subjects were further tested for endomysial (EMA) antibodies and were HLA genotyped. All subjects with antibody positivity were asked to undergo intestinal biopsy. In addition, a subset of antibody‐negative subjects were tested for HLA‐DQA1and DQB1. Results Among the 2277 subjects, 29 subjects were defined as coeliac disease autoimmune (positive results for anti‐tTG IgA and EMA‐IgA) (1.27%; 95% confidence interval, 0.81%‐1.73%), eight of them underwent biopsy and all showed coeliac disease histology (0.35%; 95% Cl, 0.11%‐0.59%). The frequency of coeliac disease autoimmunity was lowest among the Han (0.79%), followed by the Uyghur (1.81%), the Kazakh (2.05%) and the Hui (3.03%). The frequency of the HLA‐DQ2 and/or DQ8 haplotype was highest in the Uyghur (52.1%), followed by the Hui (44.4%), the Kazakh (40.0%) and the Han (39.4%). Besides, a three times higher frequency of coeliac disease autoimmunity was found among rural living subjects with significantly higher wheat consumption compared to urban living subjects (3.16% vs 0.97%, P < 0.01). Conclusions In Xinjiang, coeliac disease does occur, especially in the rural area. The HLA haplotype and environment play key roles in the development of coeliac disease.