Analysis of HLA association among North Indian HIV positive individuals with and without tuberculosis

Abstract Background The inter-individual variation during HIV infection is influenced by host genetic factors (AIDS restriction genes). Class I human leukocyte antigens, especially the molecules encoded at the B locus (HLA B), are associated with increased susceptibility to acquire HIV infection and further progression to diseases (AIDS). Rationale The aim of this study was to evaluate which variants of HLA-B are associated with the risk to acquire HIV infection in Indian population. We have recruited HIV-1 infected individuals (n = 240) with or without tuberculosis (TB) co-infection or other opportunistic infections attending the Out Patient Department (OPD) of All India Institute of Medical Sciences (AIIMS), New Delhi, India for this study. We performed HLA-A, HLA B, and HLA-DR genotyping in HIV-infected and Healthy controls. Results Our observation showed that the alleles HLA-A*24, B*35, B*51 and HLA DRB1*03 occurred more frequently among HIV-1 positive patients than control subjects suggests that they play a role in susceptibility to HIV-1 infection. Further, higher preponderance of HLA-B*35 (30.2% vs 24%), were also found in HIV+ cohort. An increased frequency of HLA-B*35 in HIV+,TB+ cohort correlates its possible role in the acquisition of tuberculosis infection being 1.7 fold higher in HIV positive studied subjects. Conclusion A comparative high-resolution analysis of B*35Px or B*35Py alleles among healthy controls and HIV+ individuals showed an overrepresentation of HLA-B*35Px alleles in the healthy Indian gene pool (58%) and in the HIV+ cohort (70%). The most common B*35 subtype found among the HIV infected subjects was B*3503/55 (20%; Px group), followed by B*3501 (10%; Py group). Our study concludes that the Indian gene pool possesses higher frequency of B*35Px alleles.