Major histocompatibility complex class II polymorphisms and risk of cervical cancer and human papillomavirus infection in Brazilian women

Infection with high-risk human papillomavirus (HPV) is the major risk factor for the development of malignant lesions in the uterine cervix. Environmental, behavioral, and ill-defined genetic factors also have been implicated in the pathogenesis of this disease. Associations between human leukocyte antigens (HLAs) and cervical cancer, precursor lesions, and HPV infections have been reported in several populations. To verify whether HLA-DRB1, -DQA1, and -DQB1 diversity is related to cervical cancer in the Brazilian population, 161 cases and 257 controls were HLA typed. Variants of DQA1 and DQB1 promoter regions were also typed in 92 cases and 228 controls. Polymorphism in HLA genes and promoters was distinguished by PCR-based methods, and the magnitude of associations was determined by logistic regression analysis. DRB1*15 [confounder-adjusted odds ratio (OR), 2.24; 95% confidence interval (CI), 1.29-3.90], DRB1*1503 (OR, 2.52; 95% CI, 1.16-5.48), and haplotype DRB1*15-DQB1*0602 (OR, 2.04; 95% CI, 1.15-3.61) were positively associated with cervical cancer. When we considered only DR15 haplotypes that did not carry the DQB1*0602 allele, the risk attributed to DRB1*15 more than doubled. A negative association was found between DQB1*05 and cervical cancer (OR, 0.57; 95% CI, 0.35-0.92), and similar trends were observed for DQA1*0101/04, DRB1*0101, and DRB1*1302. HPV positivity among controls was associated with DRB1*1503 (OR, 4.60; 95% CI, 1.33-15.9), DRB1*0405 (OR, 6.21; 95% CI, 1.66-23.2), and DQB1*0602 (OR, 2.48; 95% CI, 1.06-5.80). We suggest that HLA class II polymorphisms are involved in genetic susceptibility to cervical cancer and HPV infection in a Brazilian population from an area with a high incidence of this neoplasia.