Associations between patients with endometriosis and HLA class II; the analysis of HLA-DQB1 and HLA-DPB1 genotypes

BACKGROUND: Although the aetiology of endometriosis remains unclear, many immunological abnormalities involving changes in cell-mediated and humoral immunity may be associated with endometriosis. Several disorders are thought to be associated with particular HLA antigen types. This study examines the possible association between HLA-DQ and DP. METHODS: A total of 83 patients diagnosed with endometriosis following laparoscopic examination were typed for the HLA-DQB1 and DPB1 alleles using PCR-restriction fragment length polymorphism (RFLP). The HLA DQB1 and DPB1 allele frequencies in these patients and in 222 controls were compared. RESULTS: The prevalence of HLA-DQB1*0301 in the patient group was 16.3% (27/166 alleles), compared with 8.3% in the overall control group (37/444 alleles) and 7.7% in the females of the control group (18/234 alleles). Thus, the prevalence of the HLA-DQB1*0301 allele was significantly greater in patients with endometriosis, compared with the general controls [OR 2.13, 95% CI 1.25-3.64, P = 0.004 (chi(2) analysis), Corrected P-values; Pc = 0.049] and with the general female controls [OR 2.33, 95% CI 1.24-4.39, P = 0.008 (chi(2) analysis), Pc; NS]. There was no significant association in the frequencies of DPB1 alleles between the patients and controls. CONCLUSIONS: The HLA systems may be involved in the aetiology of endometriosis, although further study is needed.