Objectives: HIV-2 is endemic in West Africa and is characterized by lower transmissibility because of lower viral load, and HIV-2-infected persons usually have a slower progression to AIDS. The mechanisms behind the slower disease progression are unknown. The main objective was to identify specific HLA class I and II alleles that may influence the disease progression of HIV-2 infection.
Design: Cohort follow-up study.
Methods: We used high-resolution HLA typing of DNA from 437 antiretroviral naive HIV-2-infected patients from the Bissau HIV Cohort, Guinea-Bissau, to identify HLA alleles with an influence on HIV-2 disease progression. The effect of HLA-type on viral load and CD4 cell count was assessed initially by ranksum-test and t-test, followed by adjusted logistic regression and multivariable linear regression analysis, respectively.
Results: Three alleles (HLA-B58:01, HLA-DPB110:01 and HLA-DRB111:01) were associated with lower possibility of detectable baseline plasma viral load (P = 0.002, P = 0.044 and P = 0.033, respectively), and no alleles were associated with higher possibility of detectable plasma viral load. HLA-DPB110:01 and HLA-DRB111:01 were in linkage disequilibrium (P = 0.047). Patients with heterozygous HLA types in all their HLA class I loci or in one or two loci were not more likely to have undetectable viral load compared with patients that were homozygous in all their class I loci after adjusting for sex and CD4 cell count (P = 0.93 and P = 0.88, respectively).
Conclusion: The three alleles HLA-B58:01, HLA-DPB110:01 and HLA-DRB111:01 may protect against HIV-2 disease progression towards AIDS.