An evaluation of semen processing methods for eliminating HIV-1

Whether artificial insemination can provide adequate protection for discordant couples where the man is HIV-1 positive and the woman is HIV-1 negative is uncertain because of the paucity of HIV-1 elimination data assessing current sperm-washing techniques. We evaluated how effectively these techniques eliminate HIV-1 RNA and proviral DNA from semen.

Spermatozoa were separated from semen samples from HIV-1-positive patients with haemophilia by discontinuous Percoll gradient centrifugation and the 'swim-up' method. The HIV-1 RNA and proviral DNA were measured by a highly sensitive PCR. In another test 5 x 10(6) copies of HIV-1 RNA (LAI strain) were added to semen from healthy donors and then assessed after single and combined procedures.

Swim-up processing after Percoll gradient centrifugation reduced HIV-1 RNA and HIV-1 proviral DNA in semen to undetectable levels in the original specimen. Although discontinuous and continuous Percoll gradient centrifugation respectively reduced HIV-1 RNA added to seminal plasma specimens from healthy donors to less than < 1 copy from 10(5) and about 1 copy per 10(3) pre-separation copies, the discontinuous method left detectable HIV-1 RNA and proviral DNA in one out of 12 samples from patients with HIV-1 infection (8%). HIV-1 RNA and proviral DNA were decreased to undetectable levels after adding the swim-up procedure.

Swim-up separation following Percoll gradient centrifugation should offer adequate protection for HIV-1-discordant couples.