Effect of injectable progestin-only contraceptives, depot medroxyprogesterone acetate and norethisterone enanthate, on cytokine production during T-cell activation.

PROBLEM There is paucity of human data about the effects of depot medroxyprogesterone (DMPA) and norethisterone enanthate (Net-En) use on systemic immune function, which may have implications for reproductive tract infection susceptibility and transmissibility. We sought to evaluate the impact of injectable contraceptive use on T-cell responsiveness using T cells exposed in vivo and tested ex vivo. METHODS Peripheral blood mononuclear cells were obtained from healthy, HIV-negative women after 30, 90 and 180 days of DMPA, norethisterone enanthate (Net-En) or copper intrauterine device (Cu-IUD) contraceptive use. Cells were stimulated ex vivo with phorbol myristate acetate and ionomycin, stained and analysed using flow cytometry. Mixed-effects linear models were used to evaluate change in proportions of T cells producing IFN-γ, TNF-α, IL-4 and IL-13. RESULTS Compared with baseline, decreased proportions of IFN-γ-producing CD4+ and CD8+ T cells (p = .003, p = .006, respectively) and TNF-α-producing CD4+ and CD8+ T cells (p = .039, p = .034, respectively) were observed after 180 days of DMPA use. Decreased IL-4-producing CD4+ and CD8+ T cells (p = .045 and p = .024, respectively) were noted after 180 days of Net-En use. Decreased IL-4-producing CD4+ T cells were observed after 30 days (p = .035) and not after 180 days of DMPA use (p = .49). There were no changes in proportion of T cells producing IL-13 in DMPA users, nor any changes in IFN-γ, TNF-α and IL-13 in Net-En and Cu-IUD users. CONCLUSION In vivo exposure of CD4+ and CD8+ T cells to typical pharmacologic concentrations of DMPA does not cause broad suppression to stimuli; however, depletion of specific cytokine-producing T cells may occur after prolonged DMPA use.