Celiac Disease Risk In Population In Xinjiang Uyghur Autonomous Region

Celiac disease,also known as gluten-sensitive enteropathy,is a primary small intestinal malabsorption syndrome which caused by ingestion of wheat,barley,rye and other grains that contain gluten protein or their corresponding processed food in people carrying HLA-DQ2 and HLA-DQ8 genes.It is also an autoimmune disease.Previous studies showed that the population in Xinjiang regions has the highest frequency of celiac disease susceptibility genes among all provinces,cities or autonomous regions in China.At the same time,wheat is the staple food in Xinjiang region and ethnic minorities such as Uyghurs,Kazakhs,and Huis had certain genes exchange with Europeans.Before this study was carried out,there was even no case report of celiac disease in this region.Evidently,the risk for celiac disease in this region deserves great attention.In the current study,we firstly recruited inpatients presented with gastrointestinal symptoms in the Gastroenterology Department of Xinjiang Autonomous Region People's Hospital.Based on the diagnostic guidelines for celiac disease from western countries,2277 patients who met the inclusion criteria were screened and diagnosed for celiac disease;thirty-seven patients with positive anti-t TG Ig A further underwent antiEMA test and HLA-DQA1 and-DQB1 locus genotyping to diagnose patients with celiac disease autoimmunity;factors related to celiac disease autoimmunity were analyzed,and the gastrointestinal and extraintestinal symptoms of patients with celiac disease autoimmunity were described and statistically analyzed.Based on above,the initial epidemiological characteristics of celiac disease in Xinjiang were obtained.Secondly,the Han(n=70),Uyghur(n=71),Kazakh(n=52)and Hui(n=40)subjects who met the anthropological research were included for the celiac disease-related locus HLA-DRB1,-DQA1 and-DQB1 genotyping;and then the HLA-DRB1,-DQA1 and-DQB1 locus allelic frequency data from European,Central Asian and other Asian populations and the same locus allelic frequency data from the current four ethnic groups were collected for constructing the phylogenetic tree via Nei's distance,combination with the frequency of celiac disease susceptibility genes in the four ethnic groups,the potential risk for celiac disease in the population in Xinjiang was investigated from a genetic point of view.Finally,based on the wheat consumption data provided by the statistical yearbooks of China and the statistical yearbooks of every province,municipality and autonomous region and the Chinese wheat quality classification region information,a comparative analysis of gluten exposure levels between Xinjiang region and other areas of China was done;wheat consumption data from the statistical yearbooks of Xinjiang region(only rural wheat consumption data were available)and the wheat quality classification region information in Xinjiang were applied to assess the gluten exposure level in each prefecture or city;combination with the proportion of population with a high-risk for celiac disease(ethnic minorities and rural living population)in each prefecture or city in Xinjiang,the potential risk for celiac disease in population living in different prefectures or cities was evaluated,which will further interpret the risk for celiac disease in population living in Xinjiang from the perspective of the main environmental trigger related to celiac disease.The main results showed that populations living in Xinjiang region were at high-risk for celiac disease and the prevalence of celiac disease was only a tip of iceberg.Influenced by high genetic risk and environmental risk,the risk for celiac disease in Xinjiang region was likely higher than other provinces,cities or regions of China.Kashgar Prefecture of Xinjiang region had the highest proportion of population with a high-risk for celiac disease and the highest gluten exposure level,the potential risk for celiac disease in this Prefecture will be the highest.The detailed results of the study are as follows:1.The celiac disease screening study carried out in subjects presented gastrointestinal symptoms in Xinjiang region showed that the prevalence of celiac disease was 0.35(95%Confidence Interval(CI):0.11%-0.59%),and the prevalence of celiac disease autoimmune was 1.27%(95%CI: 0.81%-1.73%).The latter figure was only minor lower than the prevalence of celiac disease in American subjects presented gastrointestinal symptoms(1.47%),which indicates celiac disease is not a rare disease in Xinjiang region.2.Eight celiac disease patients confirmed with biopsies were all expressed HLADQ2.5 genotype,which indicated this genotype also is a susceptibility gene in patients with celiac disease in Xinjiang region.3.The development of celiac disease in Xinjiang region is influenced by genetic(ethnic groups)and environmental factors(living place).In our study,the prevalence of celiac disease autoimmunity in the Han subjects was significantly lower than in the minority ethnic groups(0.79% vs.2.03%,p<0.05),and in rural living subjects was significantly higher than in urban living subjects(3.16% vs.0.97%,p<0.01).4.The gastrointestinal and extraintestinal symptoms or signs in patients with celiac disease autoimmunity was varied and complex.The prevalence of celiac disease autoimmune in patients presented diarrhea,anorexia or vomit or/and nausea were all higher than 2%;almost 50% patients with celiac disease autoimmunity were presented extraintestinal symptoms or signs.5.Large number of celiac disease patients were undiagnosed in Xinjiang region,especially in minority ethnic groups,population living in rural and the lower educated population.6.The genetic relationship between Uyghur and Kazakh and European and Central Asian was closer,and both ethnic groups were more similar to each other in terms of genetic structure and frequency of celiac disease susceptibility genes(54.93% vs.53.85%),two ethnic groups both are in high-risk for celiac disease.Although no overlapping genes between Hui and European or Central Asian has been detected,the frequency of celiac disease susceptibility genes in Hui(42.50%)was second to Uyghur and Kazakh,the risk for celiac disease in Hui was second to Uyghur and Kazakh.Han was formed a cluster with Northern Han populations in the dendrogram,and carried35.71% frequency of celiac disease susceptibility genes,which indicated the lowest risk for celiac disease.7.Wheat consumption in Xinjiang region was highest compared with other regions of China,meanwhile,Xinjiang region was located in the strong-,normal wheat cultivates area,which indicates the potential risk for celiac disease in Xinjiang region probably was higher than other regions of China.8.The wheat gluten exposure level in Kashgar Prefecture was obviously higher than other Prefectures or cities in Xinjiang region,simultaneously,the proportion of population with high-risk for celiac disease in this Prefectures was also higher than other Prefectures or Cities in Xinjiang region.Therefore,the potential risk for celiac disease in Kashgar Prefecture was the highest among all Prefectures or Cities in Xinjiang region.