HLA-A and HLA-B genes are involved in the pathogenesis of IBS.

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder. The pathogenesis of IBS has not yet been fully elucidated, and the relationship between human leukocyte antigen (HLA) class I molecules and IBS is not clear. The present case-control study investigated the correlation between HLA-A and HLA-B genes and IBS. Peripheral blood samples were collected from 102 IBS patients and 108 healthy volunteers at Nanning First People's Hospital. DNA was extracted using a routine procedure, and HLA-A and HLA-B gene polymorphisms were identified by polymerase chain reaction with sequence-specific primers to determine the genotype and distribution frequency of HLA-A and HLA-B in IBS patients and healthy controls. Susceptibility and protective genes for IBS were identified using univariate and multivariate analyses. The frequency of HLA-A11 gene expression in the IBS group was significantly higher than that in the healthy control group, while the frequencies of HLA-A24, 26, and 33 gene expression were significantly higher in the healthy control group than in the IBS group (all P < .05). The frequencies of HLA-B56 and 75 (15) gene expression in the IBS group were significantly higher than those in the healthy control group, while the frequencies of HLA-B46 and 48 gene expression were significantly higher in the healthy control group than in the IBS group (all P < .05). Genes that may be related to the prevalence of IBS were included in the multivariate logistic regression, and the results suggested that the HLA-B75 (15) gene is a susceptibility gene for IBS (P = .031, odds ratio [OR] = 2.625, 95% confidence interval [CI]: 1.093-6.302), while the HLA-A24 (P = .003, OR = 0.308, 95% CI: 0.142-0.666), A26 (P = .009, OR = 0.162, 95% CI: 0.042-0.629), A33 (P = .012, OR = 0.173, 95% CI: 0.044-0.679), and B48 (P = .008, OR = 0.051, 95% CI: 0.006-0.459) genes are protective genes for IBS.