Old age and anti-cytomegalovirus immunity are associated with altered T-cell reconstitution in HIV-1-infected patients.

Objective and Design: Increasing evidence supports a parallel between HIV-1 infection and immune aging, which is particularly apparent with common changes in naive versus memory T-cell proportions. Here, we aimed at refining the value of common T-cell-associated markers of immunosenescence during HIV disease progression or aging, and at exploring further the impact in this context of old age as well as cytomegalovirus (CMV) co-infection, which is predominant in HIV-1-infected individuals.
Methods: Frequencies of naive or CD57(+) memory T cells as well as the magnitude of CMV-pp65 T cells were measured in HIV-1-infected patients grouped according to disease progression status, treatment and age.
Results: Our results indicate that the decline in naive T-cell levels rather than the accumulation of CD57(+) senescent T cells identifies best the premature development of an immunosenescence phenotype with HIV disease progression. Moreover, advanced age or mounting of strong CMV-specific responses impact independently on CD4(+) T-cell counts and recovery with antiretroviral therapy.
Conclusions: The present findings indicate that HIV-1 infection amplifies the effect of age on naive T-cell levels, and highlight the constraint on the capacity of treated patients to reconstitute their CD4(+) T-cell compartment due to age and CMV co-infection.