Aging and HIV infection

Population aging has become a global phenomenon, and HIV infection among older individuals is also increasing. Because age can affect the progression of HIV infection, we aimed to evaluate the present knowledge on HIV infection in older patients.

Literature review of the last 20 years.

Older HIV-infected patients have lower CD4(+) T cell counts, higher viral load and are more frequently symptomatic at diagnosis. The infection progresses more rapidly, with higher morbidity and lethality rates. However, older patients are more compliant to antiretroviral treatment; they experience a better virologic response, and treatment represents a positive clinical impact. Aging affects the complex interaction between HIV infection and the immune system. Both conditions contribute to the dysfunction of immune cells, including a decrease in the phagocytes' microbicidal capability, natural killer cells' cytolytic function, expression of toll-like receptors and production of interleukin-12. Chronic immune activation responsible for the depletion of CD4(+) and CD8(+) T cells in HIV infection appears to worsen with senescence. Older patients also exhibit a less robust humoral response, with the production of less avid and specific antibodies.

Both HIV and aging contribute to immune dysfunction, morbidity and mortality. However, highly active antiretroviral therapy (HAART) is beneficial for older patients, and treatment of older patients should not be discouraged.