Separation of human immunodeficiency virus type 1 from motile sperm by the double tube gradient method versus other methods

Abstract

Objective: To compare a new sperm-processing device, utilizing a double tube and gradient, with other commonly used sperm-processing methods for their abilities to exclude human immunodeficiency virus type 1 (HIV-1) from the motile sperm fraction while retaining maximum sperm yield.

Design: Laboratory experiments.

Setting: Academic research environment.

Patient(s): Healthy HIV-1 seronegative men between the ages of 25 and 55.

Intervention(s): Semen samples were spiked with HIV-1 (MN HIV-1 strain; range of concentrations: 10(-1)-10(6) TCID(50)) and subjected to one of the following sperm-processing methods: double sperm tube with discontinuous gradient of sperm separation medium formed inside (double tube gradient), conventional single tube gradient, swim-up or single tube gradient followed by swim-up (gradient/swim-up), which is the method currently used to minimize HIV-1 in semen used for assisted reproductive technology (ART) procedures. For the gradient techniques, Percoll, ISolate, and PureSperm sperm separation media were compared for efficacy of HIV-1 removal. The amount of HIV-1 remaining in the motile sperm pellet after processing was measured by reverse transcription-polymerase chain reaction (RT-PCR), NucliSens assay, or quantitative HIV-1 culture. A hemacytometer was used to microscopically assess motile sperm count.

Main outcome measure(s): HIV-1 RNA copy number, decrease in HIV-1 TCID(50), motile sperm yield.

Result(s): The double tube gradient technique was significantly better than all other methods in the removal of HIV-1 from the motile sperm fraction, and produced significantly higher sperm yields in comparison with the gradient/swim-up method.

Conclusion(s): The double tube gradient technique is a relatively simple and effective method that reduces the risk of infection by HIV-1 while producing good sperm recovery.