Frailty, markers of immune activation and oxidative stress in HIV infected elderly

People living with HIV-1 experience an accelerated aging due to the persistent and chronic activation of the immune system. This phenomenon conduces to immune exhaustion and precipitate immunosenescence. In general, frailty is defined as a syndrome of physiological degeneration in the elderly. Circulating naïve and memory T cells were studied by flow cytometry in non-frail and frail HIV-1-infected groups. Thymopoiesis, cell activation, senescence and cell proliferation were analyzed by CD31, HLA-DR/CD38, CD28/CD57 and Ki-67 expression, respectively. Plasma levels of sCD14 and MDA were measured by ELISA. Frail infected individuals showed a reduced number of memory T cells, both CD4(+) and CD8(+) populations. Activated CD3(+)CD4(+)HLA-DR(+) T cells were lower in frail individuals, and directly correlated with CD3(+)CD8(+)HLA-DR(+) and CD8(M) cells. Senescent CD8(+)CD28(−)CD57(+) cells were reduced in frail HIV-1 infected individuals and inversely correlated with CD8(RTE), CD8(N) and CD3(+)CD4(+)HLA-DR(+). Higher plasma levels of sCD14 and MDA were found in HIV-1 infected frail individuals. Our data show association among frailty, markers of immune activation and oxidative stress. Understanding the immune mechanisms underlying frailty status in HIV-1 population is of high relevance not only for the prediction of continuing longevity but also for the identification of potential strategies for the elderly.