Objective: To investigate the relation between the quantity of human i
mmunodeficiency virus type 1 (HIV-1) RNA in plasma and the risk for th
e acquired immunodeficiency syndrome (AIDS) or a decline in the CD4+ T
-cell count after seroconversion. Design: Prospective study. Patients:
62 homosexual men with documented HIV-1 seroconversion. Setting: Univ
ersity outpatient setting. Measurements: Clinical status, CD4+ T-cell
counts, and plasma and serum samples were obtained every 6 months. Hum
an immunodeficiency virus RNA in plasma was quantitated with a branche
d-DNA (bDNA) assay. Serum samples were assayed for neopterin, beta(2)-
microglobulin, and immune complex dissociated HIV-1 p24 antigen. Resul
ts: 18 of 62 (29%) men developed AIDS; 21 (34%) had a significant decl
ine in the CD4+ T-cell count without AIDS; and 23 (37%) had a stable C
D4+ T-cell count. For each participant, HIV-1 RNA results were categor
ized into one of four groups: 1) detection of HIV-I RNA(>1 x 10(4) gen
ome equivalents/mL. [Eq/mL]) in all samples; 2) detection in most samp
les (greater than or equal to 50%); 3) detection in fewer than 50% of
samples; and 4) detection in none of the samples. Detection of HIV-1 R
NA in all or most samples was strongly associated with AIDS (16 of 18
patients) and a decline in the CD4+ T-cell count (13 of 21 patients) c
ompared with a stable CD4+ T-cell count (4 of 23 patients; P < 0.001),
Conversely, the absence of HIV-1 RNA(<1 x 10(4) Eq/ml) in all or most
samples was associated with stable CD4+ T-cell counts (19 of 23 patie
nts) and a lower risk for AIDS or decline in the CD4+ T-cell count (10
of 39 patients; P < 0.001). In multivariate analysis of all laborator
y values at the seroconversion visit, a plasma HIV-1 RNA level greater
than 1 x 10(5) Eq/mL was the most powerful predictor of AIDS (odds ra
tio, 10.8; P = 0.01), Conclusions: Plasma HIV-1 RNA is a strong, CD4T-cell-independent predictor of a rapid progression to AIDS after HIV-
1 seroconversion.