Female Genital Tract Host Factors and Tenofovir and Lamivudine Active Metabolites

We previously reported the effect of contraception on cervical tenofovir concentrations in Ugandan women with human immunodeficiency virus (HIV). Here we explored the role of cervicovaginal cytokines and drug metabolizing enzymes and transporters (DMETs) to elucidate female genital tract (FGT) drug disposition in a Ugandan cohort.

Cervicovaginal fluid and cervical biopsies were collected from Ugandan women with HIV receiving tenofovir/lamivudine-based therapy and intramuscular depot medroxyprogesterone acetate (n = 25), copper intrauterine device (cuIUD; n = 12), or condoms (n = 13) as contraception. Cytokines were measured in cervicovaginal fluid (CVF). Ectocervical tenofovir diphosphate (TFVdp), lamivudine triphosphate (3TCtp), and deoxyadenosine triphosphate (dATP)/deoxycytidine triphosphate (dCTP) concentrations and immune marker/DMET gene expression were measured in cervical biopsies.

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 condom 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.

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.

We investigated changes in tenofovir diphosphate and lamivudine triphosphate due to the microbiome and inflammation. While lamivudine triphosphate was not affected by either, tenofovir diphosphate appeared to be affected by local inflammation. Specifically, Th17 cells may influence tenofovir disposition.