P40.15
Background: Data on immune mediators in the genital tract and the behavioural and clinical factors that modulate them in Sub-Saharan women are limited.
Methods: Cervicovaginal lavage (CVL) samples from 430 sexually active women from Kenya, South Africa and Rwanda were analysed for twelve soluble immune mediators. qPCR was used to quantify ten bacterial species in vaginal swab samples. We also compared the anti-HIV activity of CVL samples from bacterial vaginosis (BV)-positive women to those from women with a Nugent score of 0.
Results: Pregnant women, adolescents, women engaging in traditional vaginal practices and HIV-positive women differed in specific soluble markers compared to reference groups of adult HIV-negative women. An increase in cervical mucus, the presence of cervical ectopy, abnormal vaginal discharge and having multiple sexual partners were each associated with an increase in mediators of inflammation. Interleukin (IL)-1α, IL-1β, IL-6, IL-12 and IL-8 were elevated and the IL-1RA/(IL-1(α +β) ratio decreased in the CVLs of women with BV. Interferon gamma-induced protein (IP)-10 was decreased in BV-positive compared to BV-negative women. Lactobacillus crispatus and Lactobacillus vaginalis were associated with lower levels of pro-inflammatory cytokines and each BV-associated species with increased pro-inflammatory cytokines. The in vitro anti-HIV activity of CVLs from BV-positive women was stronger than that of BV-negative women.
Conclusions: We found significant associations of factors that can influence HIV susceptibility with the levels of soluble immune mediators in the vaginal environment of sexually active women. These factors need to be considered when establishing normative levels or pathogenic cut-offs of biomarkers of inflammation and associated risks in African women. IP-10 suppression may be one potential mechanism of immune evasion by BV-associated bacteria. Lastly, cervicovaginal secretions of women with BV may contain active anti-HIV substances that should be examined more closely.
