Abstract
Problem: Injectable contraceptive use may impact immune cell responsiveness and susceptibility to infection. We measured responsiveness of T-cells from women before and after initiating depot medroxyprogesterone acetate (DMPA) or norethisterone enanthate (Net-En). Method of study: Peripheral blood mononuclear cells collected from women aged 18-34 years prior to, at steady state, and nadir concentrations after initiating DMPA (n = 30) or Net-En (n = 36) and from women initiating copper intrauterine device (CU-IUD; n = 32) were stimulated with phorbol myristate acetate and analyzed using flow cytometry. We evaluated percentage change in T-cells expressing programmed cell death-1 (PD-1) and cytotoxic T-lymphocyte associated protein-4 (CTLA-4). Results: Compared to baseline, there were decreased numbers of CD4+CTLA4+ (P < .001) and CD8+CTLA4+ (P < .01) T-cells following ex vivo stimulation challenge at steady state DMPA concentrations and no differences at nadir concentrations (P = .781 and P = .463, respectively). In Net-En users, no differences in CD4+CTLA4+ T-cells at steady state (P = .087) and nadir concentrations (P = .217) were observed. DMPA users had fewer CD4+PD-1+ (P < .001) and CD8+PD-1+ (P < .001) T-cells at nadir concentrations. Number of CD4+PD-1+ and CD8+PD-1+ T-cells decreased at steady state concentration (P = .002 and P = .001, respectively) and at nadir concentrations after Net-En initiation (P < .001 and P < .001). In CU-IUD users, there were no changes in number of CD4+CTLA4+ (P = .426) and CD8+CTLA4+ (P = .169) and no changes in CD4+PD-1+ (P = .083) and CD8+PD-1+ (P = .936) compared to baseline. Conclusion: Activation of T-cells in response to ex vivo stimulation is suppressed at steady state DMPA concentration and resolves at nadir concentration, suggesting DMPA immunosuppressive effects may be transient.