Variations in immunogenetics, human papillomavirus (HPV) infection & predisposition to cervical cancer in Indian women

BACKGROUND & OBJECTIVES: Human papillomavirus (HPV) is the main causative agent for cervical cancer. Variability in host immunogenetic factors is important in determining the overall cellular immune response to the HPV infection. This study was carried out to confirm the association between human leukocyte antigen (HLA) class II alleles and cervical cancer in HPV infected women. METHODS: Both low and high resolution methods were used to genotype HLA class II (DRB1 and DQB1) alleles in 75 women with cervical cancer (cases) and 75 HPV positive women and 100 HPV negative women with healthy cervix (controls). Odds ratio and 95% confidence interval were calculated. Co-occurring HLA alleles (haplotype) across cases and controls were also studied. RESULTS: Significant association was found for HLA-DRB1*03(*13:01) and - DQB1*02(*02:01) with increased risk for cervical cancer. Also, HLA-DRB1*13(*13:01); -DQB1*06 and -DQB1*03:02 were significantly associated with decreased risk for cervical cancer. Haplotype analysis highlighted the significant association of HLA- DRB1*07:01-DQB1*02:02 and HLA DRB1*10:01-DQB1*05:01 with cervical cancer, while HLA-DRB1*14:04-DQB1*05:03 and DRB1*15:01-DQB1*06:01 conferred decreased risk for cervical cancer. Multivariate analysis highlighted the association of specific alleles with cervical cancer after adjusting for confounding factor age. INTERPRETATION & CONCLUSIONS: There were possible associations of specific HLA class II alleles either with risk of developing cervical cancer, or with its protection. Our results confirmed the assessment of DRB1*13 as a protective marker in HPV infection outcome. Our study also revealed protective association of homozygous haplotype DRB1*15- DQB1*06 with cervical cancer.