P06.05 Dynamics of vaginal immune correlates and microbiota in women from sub-saharan africa

Abstract

Introduction Alterations in vaginal microbiota (VMB) have been shown to increase HIV acquisition and transmission in women. We carried out a longitudinal characterisation of the VMB, soluble cervicovaginal immune mediators and their determinants in women from Sub-Saharan Africa. Methods Cervicovaginal lavages from two cohorts of sexually active women from Kenya, South Africa and Rwanda were analysed for IL-1α, IL-1β, IL-6, IL-12(p70), MIP-1β, IP-10, IL-8, GM-CSF, G-CSF, Elafin, SLPI, IL-1RA and total protein. qPCR was used to quantify total Lactobacillus, L. crispatus, L. iners, L. jensenii, L. gasseri, L. vaginalis, A. vaginae, G. vaginalis, P. bivia and E. coli in vaginal swab samples. Cohort A had 40 women with a healthy VMB (Nugent score < 4) at all five bi-weekly visits. Cohort B consisted of 40 women with incident bacterial vaginosis (BV) (Nugent score > 7) in the course of their visits. Results Cohort A: Individual Lactobacillus species were consistently present or absent within each woman over five study visits. Sexual activity was associated with reduced counts of total Lactobacillus, L. iners and Prevotella bivia but increased concentrations of IL-6, IL-12(p70) and IP-10. pH was positively associated with IL-1RA and IL1RA/IL1(α+β) ratio but negatively associated with total protein and SLPI. The amount of total Lactobacillus was significantly lower and total soluble immune mediators, MIP-1β and IL-8 higher in 14 women on progesterone- only contraception compared to those with a cycle (20 not on any contraceptives and 6 on combined pill). Cohort B: Total Lactobacillus, L. crispatus, IP-10, GM-CSF, Elafin, SLPI and total protein were all reduced during the first visit with BV. Conversely, G. vaginalis, A. vaginae, E. coli and IL-1β were increased with incident BV. Conclusion Sexual activity, progesterone, clinical symptoms of pathology and BV alter vaginal mucosal immunity in Sub-Saharan African women potentially increasing their susceptibility to HIV infection.