Even HIV-Infected Men With Undetectable HIV in Blood May Shed HIV in Semen

HIV-infected men on antiretroviral therapy sometimes still shed HIV RNA in their semen even if they have suppressed levels of HIV RNA in their blood plasma and no symptoms of other sexually transmitted diseases, according to the first-ever longitudinal study to examine the phenomenon in that population. The study was presented at ICAAC 2012.

Most of the previously available data on this topic are from cross-sectional studies with a small sample size, and concern only heterosexual men involved in medically assisted reproduction programs, according to the French research team led by Jade Ghosn, Ph.D., of the Bicetre Hospital in Paris.

In the study, researchers analyzed data from 157 HIV-infected patients, all of whom had blood plasma HIV volume of less than 50 copies/mL for at least six months. The participants ranged in age from 27 to 67, with a median age of 44. All of the participants declared themselves to be men who have sex with men (MSM). The median time since HIV diagnosis was 10.4 years, ranging from 0.8 years to 26.3 years. The participants agreed to a 48-hour period of sexual abstinence prior to sample collection.

A total of two seminal and plasma samples were collected one month apart. HIV RNA was detected in 23 out of 304 sperm samples, or 7.6% of samples. In two patients, RNA was found in both samples; in 14 patients, it was found only in the second sample; and in five patients, it was detected only in the first sample.

While those with a higher level of HIV DNA in the intracellular reservoir were 3.1 times likelier to shed RNA, even those with lower HIV DNA still sometimes shed HIV RNA in their semen, according to the study. Still, the researchers said that the study also showed, for the first time, that the size of blood HIV-1 reservoir predicts the detection of HIV RNA in the sperm.

The phenomenon of seminal HIV shedding despite apparent viral suppression in blood plasma occurred almost twice as frequently in MSM compared than among heterosexual men, the researchers said. The 7.6% rate among MSM found in this study far exceeded the 3.1% reported among heterosexual men in a study by Sidonie Lambert-Niclot, Pharm.D., Ph.D., et al, published in the journal AIDS earlier this year. (The P value for this comparison was 0.016.)

Of the patient population, 20.5%, or 32 patients, had an asymptomatic sexually transmitted disease (STI), including six cases of syphilis, 18 cases of ureaplasma urealyticum and three cases of chlamydia.

There was no association between seminal HIV RNA shedding and other factors, such as STI, HIV disease stage, nadir or current CD4 count, or duration of blood plasma HIV undetectability, according to the study.

It is not yet known whether or not the low seminal HIV RNA levels found in this study are high enough to make the virus transmissible, the study poster said. Among study participants, the median number of casual partners in the last three months was 10, with a range between 1 and 160. Of participants, 99 had a stable partner, but 62 of those reported that the partner had had casual encounters during the last three months.