Female genital tract host factors and tenofovir and lamivudine active metabolites

Abstract

Background We previously reported the effect of contraception on cervical tenofovir concentrations in Ugandan women living with HIV. Here we explored the role of cervicovaginal cytokines and drug metabolizing enzymes and transporters (DMETs) to elucidate FGT drug disposition in a Ugandan cohort. Methods Cervicovaginal fluid and cervical biopsies were collected from Ugandan women living with HIV receiving tenofovir/lamivudine-based therapy and intramuscular depot medroxyprogesterone acetate (DMPA-IM; n=25), copper IUD (cuIUD; n=12), or condoms (n=13) as contraception. Cytokines were measured in cervicovaginal fluid (CVF). Ectocervical tenofovir diphosphate (TFVdp) and lamivudine triphosphate (3TCtp), dATP/dCTP concentrations, and immune marker/DMETs gene expression were measured in cervical biopsies. Results Cervical 3TCtp was not correlated with any CVF cytokines. Cervical TFVdp was correlated with IL-10, IL-7, and IL-17 in CVF. CCR5 mRNA expression in cervical biopsies was higher in cuIUD-users versus condoms-users. Using multivariable linear regression, CVF IL-17, tissue dATP, plasma estradiol, and plasma tenofovir were all significant predictors of cervical TFVdp. Tissue dCTP and plasma lamivudine were significant predictors of cervical 3TCtp. Conclusions TFVdp concentrations in cervix appear to be influenced by local inflammation. In contrast, 3TCtp FGT exposure was not affected by genital inflammation or DMETS. CuIUD users have more immune cells present, which may in turn influence local TFVdp disposition.