Presence of human immunodeficiency virus in semen and its elimination by semen processing: Current research

Background: Although human immunodeficiency virus (HIV) particles can be present in semen and transmit infection, a previous clinical study suggested that semen processing could eliminate infectious HIV particles. To examine the efficiency of the elimination of HIV from seropositive semen samples, the authors studied HIV viral load in semen and that in processed sperm suspension. Methods: For the in vivo study, semen samples from five seropositive males were processed by continuous Percoll density gradient-swimup. In the in vitro study, to calculate elimination efficiency, semen from seronegative donors was mixed with concentrated viral suspension and processed using the same protocol. Viral load was estimated using nested competitive polymerase chain reaction (PCR) and reverse transcript (rt)-PCR. Results: Viral load of semen samples ranged from 0.5 to 15 x 10³ copies/mL. After processing, motile sperm were recovered from three of five semen samples from seropositive males. None of the suspension with motile sperm contained more than 0.1 x 10³ copies/mL of virus in suspension. For the in vitro experiment, viral load was decreased from 400 x 10³ copies/mL to below 0.1 x 10³ copies/mL by semen processing. Human immunodeficiency virus particles in liqueous fraction were almost completely eliminated from infected semen by processing. Conclusion: If it can be demonstrated that infectious HIV particles do not exist in processed semen from early seropositive males, it might be possible to use these sperm suspensions for artificial insemination or in vitro fertilization in the future.