Rate of decline of percentage CD4+ cells is faster in HIV-1 than in HIV-2 infection.
Increasing evidence suggests that the pathogenesis of HIV-1 is different from that of HIV-2. Thus, we have measured, longitudinally at various times over a median follow-up of 2.1 years, the percentage CD4+ cells 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 patients with either infection. Multilevel statistical modeling techniques showed that after stratifying for HIV status, the rate of decline of CD4% was faster among patients who died than among those who survived (difference in rate of decline = 2.34% CD4+ cells/year; p = 0.0002). After stratifying for survival status, the rate of decline was faster and less variable among patients infected with HIV-1 than among patients infected with HIV-2 (difference in rate of decline = 1.12% CD4+ cells/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 homogeneous 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 as that in HIV-1 infection. The reasons for this marked heterogeneity need elucidation to understand the disease and to target therapeutic interventions against HIV-2 in those most at risk.
Jaffar
S
S
Medical Research Council Laboratories, Fajara, The Gambia.
Wilkins
A
A
Ngom
P T
PT
Sabally
S
S
Corrah
T
T
Bangali
J E
JE
Rolfe
M
M
Whittle
H C
HC
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000328:Adult; D018791:CD4 Lymphocyte Count; D005260:Female; D015497:HIV-1; D006801:Humans; D008297:Male