Immune reconstitution after 2 years of successful potent antiretroviral therapy in previously untreated human immunodeficiency virus type 1-infected adults

Today's antiretroviral combination regimens can induce significant and sust ained decreases in human immunodeficiency virus (HIV)-RNA levels, allowing the immune system to recover. To what extent immune reconstitution is possi ble and what factors determine the outcome have thus far not been resolved. We studied 19 subjects, heated for 2 years with protease inhibitor-contain ing triple therapy, who had a strong suppression of HIV-RNA levels, CD4(+) T-cell numbers increased from medians of 170 to 420 x 10(6) cells/L, but in a number of subjects T-cell numbers did not further increase after week 72 , without having reached normal values, Long-term CD4(+) T-cell change was mainly caused by a slow but continuous increase in naive CD4(+) T cells (CD 45RA(+)CD62L(+)) and was predicted by the baseline number of these cells. O ur data indicate that long-term immunological recovery is gradual, even dur ing strong suppression of viral replication, not always complete, and depen dent on the preexisting level of naive CD4(+) T cells.