PrEP Effectiveness May Be Undermined by Genital Inflammation

Genital inflammation may be associated with reduced effectiveness of HIV prevention efforts, according to the results of a recent study.

Previous research has suggested that antiretroviral drugs taken as pre-exposure prophylaxis can help to prevent HIV infection, with widely varying magnitude of protection, attributed mainly to product adherence.

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However, biological factors are likely also associated with this lack of effectiveness, according to the authors of the current study. They sought to determine whether cervicovaginal concentrations of 9 proinflammatory cytokines influenced the protective effects of 1% tenofovir gel.

In a post hoc prospective analysis, they examined data from the CAPRISA 004 trial, which involved 774 women and demonstrated protection against HIV with tenofovir gel. A graduated cytokine score was used to define genital inflammation.

Overall, in women without genital inflammation, tenofovir was 57% protective against HIV, but only 3% protective in women with genital inflammation. In women who highly adhered to treatment, tenofovir was 75% protective in women without inflammation and -10% protective in women with inflammation.

“Immunological predictors of HIV risk may modify the effectiveness of tools for HIV prevention; reducing genital inflammation in women may augment HIV prevention efforts,” the researchers concluded.

—Michael Potts

Reference:

McKinnon LR, Liebenberg LJ, Yende-Zuma N, et al. Genital inflammation undermines the effectiveness of tenofovir gel in preventing HIV acquisition in women [published online February 26, 2018]. Nat Med. doi:10.1038/nm.4506.