Influence of Hormonal Contraceptive Use and HIV on Cervicovaginal Cytokines and Microbiota in Malawi

Abstract

Important questions remain on how hormonal contraceptives alter the local immune environment and the microbiota in the female genital tract and how such effects may impact susceptibility to HIV infection. We leveraged samples from a previously conducted clinical trial of Malawian women with (n = 73) and without (n = 24) HIV infection randomized to depot medroxyprogesterone acetate (DMPA) or the levonogestrel implant in equal numbers within each group and determined the effects of these hormonal contraceptives (HCs) on the vaginal immune milieu and the composition of the vaginal microbiota. Longitudinal data for soluble immune mediators, measured by multiplex bead arrays and enzyme-linked immunosorbent assays (ELISAs), and vaginal microbiota, assessed by 16S rRNA gene amplicon, were collected prior to and over a period of 180 days post-HC initiation. DMPA and levonogestrel had only minimal effects on the vaginal immune milieu and microbiota. In women with HIV, with the caveat of a small sample size, there was an association between the median log₁₀ change in the interleukin-12 (IL-12)/IL-10 ratio in vaginal fluid at day 180 post-HC compared to baseline when these women were classified as having a community state type (CST) IV vaginal microbiota and were randomized to DMPA. Long-lasting alterations in soluble immune markers or shifts in microbiota composition were not observed. Furthermore, women with HIV did not exhibit increased viral shedding in the genital tract after HC initiation. Consistent with the results of the ECHO (Evidence for Contraceptive Options and HIV Outcomes) trial, our data imply that the progestin-based HC DMPA and levonorgestrel are associated with minimal risk for women with HIV. (This study has been registered at ClinicalTrials.gov under registration no. NCT02103660). IMPORTANCE The results of the Evidence for Contraceptive Options and HIV Outcomes (ECHO) trial, the first large randomized controlled clinical trial comparing the HIV acquisition risk of women receiving DMPA, the levonorgestrel (LNG) implant, or the copper intrauterine device (IUD), did not reveal an increased risk of HIV acquisition for women on any of these three contraceptives. Our study results confirm that the two different progestin-based hormonal contraceptives DMPA and levonogestrel will not increase the risk for HIV infection. Furthermore, DMPA and levonogestrel have only minimal effects on the immune milieu and the microbiota in the vaginal tract, attesting to the safety of these hormonal contraceptives.

Keywords: HIV; contraception; cytokines; depot medroxyprogesterone acetate injectable; inflammation; levonorgestrel implant; microbiome; progestin; progestin contraception.

FIG 1

Study overview. Shown is an overview of the enrollment steps for the randomized trial to test the effect of DMPA versus LNG implant on local immune markers and the vaginal microbiome in women without HIV and in WHIV.

FIG 2

Vaginal cytokine milieu prior to contraceptive start. Shown are the median concentrations ± 95% confidence interval (CI) of various immune markers in cervicovaginal lavage samples of women without HIV (gray triangles) in comparison to WHIV (black triangles) at study visit 2. Statistical comparisons were performed by Mann-Whitney test.

FIG 3

Changes in immune markers of WHIV after contraceptive initiation. Shown are the median concentrations ± 95% CI of various immune markers in CVL samples of WHIV assigned to DMPA (top panels) or the LNG implant (bottom panels) at study visit 4 (gray triangles, left panels) and visit 7 (right panels, gray triangles) compared to visit 2 (black triangles). Statistical comparisons were performed by paired Wilcoxon rank test.

FIG 4

Changes in immune markers in women without HIV after contraceptive initiation. Shown are the median concentrations ± 95% CI of various immune markers in CVL samples of women without HIV assigned to the DMPA (top panels) or the LNG implant (bottom panels) group at study visit 4 (gray circles, left panels) and visit 7 (right panels, gray circles) compared to visit 2 (white circles).

FIG 5

Comparative analysis of changes in vaginal immune markers dependent on the type of contraceptive method. The median concentrations ± 95% CI of various immune markers in CVL samples of women without HIV (A) or WHIV (B) were compared at visit 2 (prior to contraceptive use), visit 4 (day 3 post-contraceptive start), and visit 7 (6 months post-contraceptive start) between women assigned to the DMPA (white circles) or the LNG implant (gray circles) group.

FIG 6

Changes in the CST classifications for each individual stratified by HC method and HIV status.

FIG 7

Correlation between the DMPA, IL-12p40, and L. iners abundance. Panel A shows the negative correlation between the probability of being assigned to DMPA versus the change in IL-12p40 concentration (log₁₀) in WHIV. Panel B illustrates the negative correlation between the change in IL-12p40 concentration (log₁₀) at visit 7 compared to visit 2 versus the change in relative L. iners abundance (log₁₀) in WHIV.