ALTERATIONS IN THE IMMUNE-RESPONSE OF HUMAN-IMMUNODEFICIENCY-VIRUS (HIV)-INFECTED SUBJECTS TREATED WITH AN HIV-SPECIFIC PROTEASE INHIBITOR,RITONAVIR

Effects of a human immunodeficiency virus (HIV) type 1 protease inhibi tor, ritonavir, were evaluated in 21 patients enrolled in a phase I/II study, The magnitude and rates of CD4 and CD8 lymphocyte increase, ch anges in subsets of CD4 and CD8 lymphocytes, and proliferative respons es to mitogen and antigens were analyzed, Significant increases were n oted in CD4 and CD8 lymphocyte counts; numbers of CD4CD45RO lymphocyte s increased significantly by week 1 of therapy, Increases in the CD4CD 45RA subset were observed at week 4, Reductions in the percentage of C D4 and CD8 lymphocytes expressing CD38 were noted, Increases in prolif erative responses to phytohemagglutinin were noted in 6 of 7 patients and correlated with duration of virus load suppression, Increased resp onses to recall antigens and to HIV-specific proteins were observed, T reatment with ritonavir produced alterations in the immune system that included changes in T cell subset distribution and increases in CD4 a nd CD8 lymphocyte numbers and of lymphocyte function.