Older Age Is Associated with Peripheral Blood Expansion of Naïve B Cells in HIV-Infected Subjects on Antiretroviral Therapy

Older HIV infected subjects were previously found to have significant B cell expansion during initial antiretroviral therapy in a prospective age-differentiated cohort of older and younger ($45 vs. #30 years) HIV-infected subjects initiating antiretroviral therapy (ART) through the AIDS Clinical Trials Group. Here to further describe this expansion, using a subset of subjects from the same cohort, we characterized B cell phenotypes at baseline and after 192 weeks of ART in both older and younger HIV-infected groups and compared them to uninfected age-matched controls. We also examined whether phenotypes at baseline associated with response to tetanus and hepatitis A vaccine at 12 weeks. Forty six subjects were analyzed in the HIV infected group (21 older, 25 younger) and 30 in the control group (15 per age group). We observed