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

Abstract

BackgroundThe 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 (HLAB), are associated with increased susceptibility to acquire HIV infection and further progression to diseases (AIDS). RationaleThe 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, HLAB, and HLA-DR genotyping in HIV-infected and Healthy controls. ResultsOur 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. ConclusionA 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.