Enhancement of human immunodeficiency virus type 1-specific CD4 and CD8 T cell responses in chronically infected persons after temporary treatment interruption

Immunologic and virologic outcomes of treatment interruption were compared for 5 chronically human immunodeficiency virus (HIV)-infected persons who h ave maintained antiretroviral therapy-mediated virus suppression, as compar ed with 5 untreated controls. After a median interruption of 55 days of the rapy accompanied by rebound of virus, reinitiated therapy in 4 of 5 subject s resulted in suppression of 98.86% of plasma virus load by 21-33 days and no significant decrease in CD4 T cell percentage from baseline. Increased T helper responses against HIV-1 p24 antigen (P = .014) and interferon-gamma -secreting CD8 T cell responses against HIV-1 Env (P = .004) were present d uring interruption of therapy and after reinitiation of treatment. The rema ining subject whose treatment was interrupted did not resume treatment and continued to have a low virus load (<1080 HIV-1 RNA copies/mL) and persiste nt antiviral cell-mediated responses. In summary, cellular immunity against autologous HIV-1 has the potential to be acutely augmented in association with temporary treatment interruption in chronically infected persons.