• Efavirenz (EFV)-Containing Antiretroviral (ARV) Therapy (T) Effectively Reduces HIV RNA in the Seminal Plasma (SP) of HIV-1-Infected Men (M) (Poster 750)
  Authored by S. Reddy, J. Kim, J. Eron, S. Fiscus, K. Gotzkowsky, D. Manion, W. Fiske, M. Cohen, and A. Kashuba
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Suppression of viral replication in seminal fluid may have important implications for sexual transmission of HIV and for selection of resistant virus in that body compartment. These investigators previously have demonstrated achievement of therapeutic concentrations of efavirenz in seminal plasma (ICAAC 2000). In the current study they reported on the effects of therapy on viral load in both seminal and blood plasma.

Sixteen men (12 already receiving EFV-based combination therapy with detectable RNA in blood plasma in five, and four previously untreated) provided serial samples over a 30-40 day period. For the naive patients, EFV decreased viral load in seminal plasma in concert with reductions in blood plasma. In subjects chronically treated with EFV there was evidence of low level replication in blood in three subjects that was not detected in semen. All 12 experienced subjects did not have detectable virus in seminal plasma at baseline, but two subjects became detectable during the study, one transiently and one persistently. Although two of the experienced subjects had substantial plasma viral loads of 3.3 and 3.9 logs, respectively, neither had detectable HIV RNA in seminal plasma. Three of the four naive subjects demonstrated significant declines in plasma viral load determinations and had no detectable virus in semen. The fourth naive subject had only a transient decline in blood despite a 1.3 log decline in semen to an undetectable level. Overall, discordant values for seminal and blood plasma HIV RNA were observed in 25%.

The treatment-experienced subject who developed persistent, substantial viral load (3.3 logs) detected in semen but not in blood suggests that virus cannot only be compartmentalized but that resistance may first arise in a site other than blood. These data provide yet another reason for seropositive individuals to practice safe sex, even when they are being treated, are in a monogamous relationship and have a low or undetectable plasma viral load.