Progesterone-based injectable hormonal contraceptives (HCs) potentially
modulate genital barrier integrity and regulate the innate immune environment in
the female genital tract, thereby enhancing risk for STIs or HIV infection. We
investigated the effects of injectable HC use on concentrations of inflammatory
cytokines and other soluble factors associated with genital epithelial repair
and integrity. The concentrations of 42 inflammatory, regulatory, adaptive,
growth factors and hematopoetic cytokines, five matrix metalloproteinases
(MMPs), and four tissue inhibitors of metalloproteinases (TIMPs) were measured
in cervicovaginal lavages (CVLs) from 64 HIV negative women using injectable HCs
and 64 control women not using any HCs, in a matched case-control study. There
were no differences between groups in the prevalence of bacterial vaginosis (BV;
nugent score ≥7), or common sexually transmitted infections (STIs). In
multivariate analyses adjusting for condom use, sex work status, marital status,
BV and STIs, median concentrations of chemokines (eotaxin, MCP-1, MDC), adaptive
cytokines (IL-15), growth factors (PDGF-AA) and a metalloproteinase (TIMP-2)
were significantly lower in CVLs from women using injectable HCs than controls.
In addition, pro-inflammatory cytokine IL-12p40 and chemokine fractalkine were
less likely to have detectable levels in women using injectable HCs compared to
those not using HCs. We conclude that injectable HC use was associated with an
immunosuppressive female genital tract innate immune profile. While the
relationship between injectable HC use and STI or HIV risk is yet to be
resolved, our data suggest that injectable HCs effects were similar between STI
positive and STI negative participants.