INCREASE IN NEUTRALIZING ANTIBODY TITER AGAINST SEQUENTIAL AUTOLOGOUSHIV-1 ISOLATES AFTER 16 WEEKS SAQUINAVIR (INVIRASE) TREATMENT

The humoral immune response to HIV infection plays an important role i n determining disease progression. Few and discordant results correlat e changes in neutralizing antibody (NtAb) titer with antiretroviral Tr eatment. The NtAb titer against autologous-HIV was evaluated in 33 pat ients treated with the protease inhibitor saquinavir (SOV, Invirase) a nd zidovudine (ZDV) alone or in combination. Ten out of 33 (30%) patie nts showed a significant increase (4-fold or greater) in NtAb titer fr om baseline in response to the initiation of therapy. A significant co rrelation (P = 0.007) was found between an increase in NtAb titer and treatment with SOV atone (5 subjects) or in combination (5 subjects). A significant decrease in NtAb titer was detected in 7 patients, 5 of whom were treated with ZDV alone. After one year of therapy a signific ant decrease in HIV-RNA copy number (> 0.5 log) with respect to baseli ne value was detected only in patients treated with SOV alone or in co mbination. Patients with increased NtAb titer showed a significantly r educed HIV-RNA copy number and increased CD4(+) cell count at week 16 of treatment which were sustained up to week 52. These data suggest th at treatment with SOV can improve neutralizing activity against autolo gous virus as well as bring about a significant and sustained reductio n in viral load. (C) 1997 Wiley-Liss, Inc.