Decline in CD4+ cell numbers reflects increase in HIV-1 replication.

Changes in CD4+ cell numbers were studied in relation to the presence of HIV-1 antigen (HIV-1-Ag) in serum from homosexual men followed prospectively. During 30 months of follow-up the mean CD4+ cell number (x 10(9) per liter) was stable in 134 at entry HIV-1 antibody (HIV-1-Ab) seropositives, who remained HIV-1-Ag negative (from 0.59 to 0.62) and declined in 38 at entry HIV-1-Ab seropositives who were persistently HIV-1-Ag positive (from 0.43 to 0.34). In sera of 9 of 65 HIV-1-Ab seroconverters HIV-1-Ag was detected only once, 3 months before or concomitantly with antibody seroconversion. Another 11 men became persistently HIV-1-Ag positive with antibody seroconversion or 2-6 weeks thereafter. A decline in CD4+ cell numbers was seen between 6 months before and the moment of HIV-1-Ab seroconversion, independently of duration and level of antigen expression. This indicates initial HIV-1 replication in both HIV-1-Ag negatives and positives. Following antibody seroconversion, HIV-1-Ag negatives had higher CD4+ cell numbers than HIV-1-Ag positives. Similarly to those who were HIV antigenemic from entry of the study, the HIV-1-Ab seroconverters who concomitantly with seroconversion or shortly thereafter became HIV-1 antigenemic showed a steady and significant (p = 0.01) decline in CD4+ cell numbers. In those who remained HIV-1-Ag negative after antibody seroconversion, CD4+ cell numbers were stable during follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)