HIV-1 in semen: Determination of proviral and viral titres compared to blood, and quantification of semen leukocyte populations

This study was carried out to determine the relationship between proviral D NA and viral RNA titres in semen compared with blood. In addition, the asso ciation between semen leukocyte counts with detection frequency and absolut e levers of human immunodeficiency virus type 1 (HIV-1) nucleic acids was a lso assessed. Paired samples of blood and semen were collected from a cohor t of individuals with different blood CD4 cell counts, and whose anti-HIV t herapy had not changed in the preceding 3 months. The cell-associated provi ral DNA titres and cell-free plasma viral RNA titres were determined using nested primer polymerase chain reaction and NASBA(TM), respectively. In add ition, leukocyte counts were determined by immunocytochemical and cytochemi cal staining of a subset of semen samples. HIV-1 proviral DNA was detected in 100% and 47%, and viral RNA was detected in 76% and 63%, of blood and se men samples tested, respectively. HIV-1 proviral DNA and viral RNA titres i n blood were higher than in corresponding semen samples, although the diffe rence observed in viral RNA titres was not statistically significant. Provi ral DNA and viral RNA titres were correlated between the two body fluids, a nd within the semen, although some individuals had disparate semen and bloo d titres or detection rates, indicating genital tract compartmentalisation. In addition, detection of HIV-1 proviral DNA, but not of HIV RNA, in semen was associated with elevated semen leukocyte counts, although this latter finding requires verification in future studies of larger numbers of patien ts. (C) 1999 Wiley-Liss, Inc.