Analysis of HLA association among North Indian HIV-positive individuals co-infected with Mycobacterium tuberculosis

Background: Genetic variation in HLA genes influence the immune response and may thus contribute to differential development of tuberculosis (TB) in HIV-infected individuals. The study was designed to determine whether HLA polymorphisms influence the development of Mycobacterium tuberculosis infection in HIV-infected individuals. Materials and Methods: Fifty HIV-positive individuals without TB (HIV+TB-), 50 HIV patients co-infected with TB (HIV+TB+) and 50 control subjects (HIV-TB-) were analyzed for HLA Class I and II polymorphisms. Results: In HLA Class II, frequency of occurrence of DRB1∗13 (OR 3.165, CI 1.176-8.518, P value 0.019), DRB5 (OR 2.253, CI 1.011-5.019, P value 0.045) and DQB1∗06 (OR 2.705, CI 1.197-6.113, P value 0.016) were increased in HIV+TB+compared to HIV+TB-. HLA DQB1∗02 (OR 0.436, CI 0.185-1.029, P value 0.05) on the other hand conferred a protective role. In HLA Class I, frequency of B∗15 (OR 2.705, CI 1.040-7.036, P value 0.038) was increased, whereas B∗51 (OR 0.148, CI 0.031-0.706, P value 0.007) was decreased in HIV+TB+group compared to HIV+TB-. These differences however were not significant when compared with healthy controls. Conclusion: HLA polymorphisms independently did not account for the susceptibility to either of the disease mostly, although they seem to play a role once the infection(s) has established in a particular individual. Further studies are needed on a larger sample size to confirm these observations.