RATE OF DECLINE OF PERCENTAGE CD4(-1 THAN IN HIV-2 INFECTION() CELLS IS FASTER IN HIV)

Increasing evidence suggests that the pathogenesis of HIV-1 is differe nt from that of HIV-2. Thus, we have measured, longitudinally at vario us times over a median follow-up of 2.1 years, the percentage CD4(+) c ells of 94 patients infected with HIV-1 and 164 patients infected with HIV-2. The pattern of decline of CD4% over time was linear for patien ts with either infection. Multilevel statistical modeling techniques s howed that after stratifying for HIV status, the rate of decline of CD 4% was faster among patients who died than among those who survived (d ifference in rate of decline = 2.34% CD4(+) cells/year; p = 0.0002). A fter stratifying for survival status, the rate of decline was faster a nd less variable among patients infected with HIV-1 than among patient s infected with HIV-2 (difference in rate of decline = 1.12% CD4(+) ce lls/year; p = 0.05). The proportion of patients who showed no fall in CD4(+) cells was higher in HIV-2 than in HIV-1 infection (p = 0.026). These data suggest fundamental differences between the two infections, with HIV-1 being more pathogenic resulting in a faster and more homog eneous rate of decline than HIV-2. In HIV-2 infection, disease in many patients progresses slowly, but in some the advance is just as fast a s that in HIV-1 infection. The reasons for this marked heterogeneity n eed elucidation to understand the disease and to target therapeutic in terventions against HIV-2 in those most at risk.