Post-prostatic massage fluid/urine as an alternative to semen for studying male genitourinary HIV-1 shedding

Graham SM, Krieger JN, Githua PL, Wamuyu LW, Wale S, Ramko KM, Dragavon JA, Muller CH, Holte SE, Mandaliya KN, McClelland RS, Peshu NM, Sanders EJ, Coombs RW
Sex Transm Infect. 2011;87

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OBJECTIVES: Genitourinary tract samples are required to investigate male HIV-1 infectivity. Because semen collection is often impractical, the acceptability, feasibility and validity of post-prostatic massage fluid/urine (post-PMF/U) was evaluated for studying male genitourinary HIV-1 shedding. METHODS: HIV-1-seropositive men were evaluated after 48 h of sexual abstinence. At each visit, a clinician performed prostatic massage, then post-PMF/U and blood were collected. Participants provided semen specimens 1 week later. An audio computer-assisted self-interview (ACASI) administered after each specimen collection evaluated acceptability, adherence to instructions and recent genitourinary symptoms. HIV-1 RNA was quantified using a real-time PCR assay. Detection and quantitation of HIV-1 RNA and stability over visits were compared for semen, post-PMF/U and blood. RESULTS: Post-PMF/U was successfully obtained at 106 visits (64%) and semen at 136 visits (81%, p<0.001). In ACASI, discomfort was rated higher for post-PMF/U collection (p=0.003), but there was no significant difference in acceptability. Detection of HIV-1 RNA in post-PMF/U was associated with detection in semen (p=0.02). Semen and post-PMF/U HIV-1-RNA levels were correlated (rho=0.657, p<0.001). Concordance of results at repeat visits was 78.9% for post-PMF/U (kappa=0.519, p=0.02) and 89.5% for both blood and semen (kappa=0.774, p=0.001). CONCLUSIONS: Although semen collections were more successful, both post-PMF/U and semen collections were acceptable to many participants. HIV-1 RNA detection and levels were closely associated in semen and post-PMF/U, and results were relatively stable across visits. To assess male HIV-1 infectivity, post-PMF/U may represent a valid alternative when semen cannot be obtained.