RETRACTED: Characterization of long-term survivors of human immunodeficiency virus type 1 infection (Retracted article. See vol 64, U5, 1998)

A small population of HIV-l-infected individuals remains clinically healthy and immunologically normal for more than ten years. We have studied ten subjects who have been asymptomatic with normal and stable CD4(+) lymphocyte counts, despite 12 to 16 years of HIV-l infection, to gain information on the determinants of nonprogression. Multiple methods were used to determine the viral load in their blood. Plasma cultures were uniformly negative for infectious virus. However, particle-associated HIV-1 RNA was detectable in four subjects using a sensitive branched DNA amplification assay. In peripheral blood mononuclear cells (PBMC), infectious HIV-I was quantified in three subjects using a standard limiting-dilution culture method. Infectious virus was recovered from another subject using a CD8-depleted culture. In contrast, six subjects had no detectable infectious virus in PBMC. All had detectable viral DNA in PBMC by a quantitative polymerase chain reaction assay, but the copy numbers were low; ranging from 10 to 100 copies per 10(6) PBMC in all but two subjects. Overall, the viral burden in the plasma and PBMC of long-term survivors was orders of magnitude lower than those typically found in progressors. Possible mechanisms for low levels of HIV-1 in vivo were examined experimentally.