Tfh Dysfunction in HIV and Aging

This study examines how HIV infection and aging affect certain immune cells called T follicular helper (Tfh) cells, which help the body produce antibodies. Understanding this may help researchers design better vaccines and treatments for HIV-positive people as they age. **You may be eligible if...** - You are HIV-positive, have been on antiretroviral therapy (ART) for at least 1 year, have a CD4 count above 200, and have an undetectable viral load - You are HIV-negative (as a comparison group) - You are willing to provide blood samples **You may NOT be eligible if...** - You are HIV-positive but not virally suppressed on treatment - You have active infections or cancers that could affect immune function - You have recently received vaccines that might alter immune cell levels Talk to your doctor to see if this trial is right for you.