Cervicovaginal shedding of HIV type 1 is related to genital tract inflammation independent of changes in vaginal microbiota

Abstract

We examined the relationship of proinflammatory vaginal cytokines and secretory leukocyte protease inhibitor (SLPI) with genital HIV-1 shedding after controlling for genital coinfections. Fifty-seven HIV-1-infected women in Seattle, WA (n = 38) and Rochester, NY (n = 19) were followed every 3-4 months for a total of 391 visits. At each visit, plasma and cervicovaginal lavage (CVL) were tested for HIV-1 RNA using qPCR. Vaginal samples were tested for bacterial vaginosis, yeast, hydrogen peroxide-producing Lactobacillus colonization, Trichomonas vaginalis, Neisseria gonorrhea, Chlamydia trachomatis, CMV, and HSV shedding. CVL interleukins (IL)-1β, IL-6, IL-8, and SLPI were measured using ELISA. Linear regression with generalized estimating equations examined effects of cytokine concentrations on CVL HIV-1 RNA, adjusted for plasma HIV RNA, and measured coinfections. CVL IL-1β and IL-8 were significantly associated with CVL HIV-1 RNA. This persisted after adjusting for plasma HIV-1 RNA. Higher levels of IL-1β were associated with higher concentrations of HIV-1 RNA in CVL (β = 0.25, 95% CI 0.09, 0.42), as were higher levels of IL-8 (β = 0.34, 95% CI 0.17, 0.50). Adjusting for the presence of the coinfections described, this relationship was attenuated for IL-1β (β = 0.16; 95% CI -0.01, 0.33) but still significant for IL-8 (β = 0.29; 95% CI 0.13, 0.45). The proinflammatory cytokines IL-1β and IL-8 are associated with higher cervicovaginal HIV-1 RNA concentrations, even after controlling for plasma viral load and vaginal microbial cofactors. This association suggests that there may be additional, noninfectious causes of inflammation that increase cervicovaginal HIV-1 shedding.