A Study On The Association Of HLA Class â…¡gene With Endometriosis Of Women In Southern China

Endometriosis is one of the most enigmatic disorders affecting reproductive health of women. No clear understanding of its pathogenesis or therapy was revealed. A number of clinical and experimental evidences indicated that human endometriosis was an autoimmune disease, which has a strong familial tendency. Immunological and genetic factors may play a critical role. Because of the tendency of autoimmune disease and genetic susceptibility for this disease, one might expect an association of the disease with certain human lymphocyte antigen (HLA) type. The HLA plays a critical role in susceptibility and resistance to autoimmune disease. The natural function of human MI-IC (HLA) molecules is to bind and present peptides derived from both self and foreign proteins to T lymphocytes. A strong T- cells response might protect against disease or induce pathology, depending on the site and nature of antigen recognized. Persons involved in disease might occur if a given I-LLA molecule presented a athogenic peptide?to T cells. Allelic specific peptide binding to a given HLA class II allele may determine the resistance and susceptibility to the disease. In order to further study the genetic disposition to endometriosis, HLA class II genes of patients with endometriosis and controls group were genotyped and analyzed in association of the disease. The allelic types of HLA-DQB1, DQA1 and HLA-DRB1, DPB1 were detected by PCR-Sequence Specific Oligonuclietide (PCR-SSO) , PCR-Sequence Specific Primers (PCR-SSP) and sequence-based typing (SBT) technique. The patients in this study were women of reproductive age undergoing laparoscopy for suspected endometriosis and confirmed by histological examination. To ensure their close genetic background and living environment, the patients and controls were chosen from the same region in southern China. In our study, we first found that the frequency of HLA-DQA 1 0401 allele in patients with endometriosis group was marked higher than that in control group (p=0.019, RR=5.733), contrarily the frequency of HLA DQBI 0503 and DQA1 0301 allele in control group was higher than that in patients (p=O.Ol5, RR=0.108; p=O.OO5, RR=0253). We do not find any association between HLA-DRB 1 , DPB 1 type and the disease. This study suggested that HLA class II may contribute the susceptibility and resistance to endometriosis. HLA-DQA 1 0401 may be a susceptible alleles of endometriosis, whereas HLA DQB1 0503 and DQA1 0301 may be a resistance of endometriosis. Further analysis provided a possible association between resistance to endometriosis and Asp at the 57 position of beta chain of DQ molecule encoded by DQB1 0503.