Early CD4+ T Cell Recovery in Human Immunodeficiency Virus-Infected Patients Receiving Effective Therapy Is Related to a Down-Regulation of Apoptosis and Not to Proliferation

This prospective study investigated the contributions of apoptosis and proliferation of CD4 + T cells obtained by the introduction of a new antiretroviral treatment for human immunodeficiency virus infection. Virus load; T cell counts; apoptosis of T cell subsets, including naive cells; and proliferation were determined from treatment initiation to the third month in a cohort of patients. An increase in CD4 + T cell count ≥100 cells/μL over baseline was considered to be a satisfactory immune reconstitution. Sixty-nine patients completed the protocol, 22 of whom met our definition of a satisfactory immune reconstitution, showing a significantly more pronounced reduction in spontaneous CD4 + T cell apoptosis at month 1 as well as month 3, compared with the other patients. In contrast, neither Fas-induced apoptosis down-regulation nor Fas-induced increased proliferation capacity was associated with a satisfactory immune reconstitution. Down-regulation of CD4 + T cell apoptosis by antiretroviral treatment is the main mechanism associated with early CD4 + T cell increase.