Cytokine concentration and T cell subsets in the female genital tract in the presence of bacterial vaginosis and Trichomonas vaginalis

Marisa R Young ^1* Lisa B Haddad ^1,2 Lyle McKinnon ³ Walter Obiero Ochieng ⁴ Marta Rowh ¹ Amanda Gill ¹ Igho Ofotokun ¹ Supriya Dinesh Mehta ^5,6

• ¹ School of Medicine, Emory University, Atlanta, United States
• ² Population Council, New York, New York, United States
• ³ Family Medicine, Max Rady College of Medicine ,University of Manitoba, Winnipeg, Manitoba, Canada
• ⁴ Centers for Disease Control and Prevention (Georgia), Atlanta, Georgia
• ⁵ Department of Internal Medicine, Rush Medical College, Rush University, Chicago, Illinois, United States
• ⁶ School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States

Trichomonas vaginalis (TV) and bacterial vaginosis (BV) are highly prevalent vaginal infections. Both are associated with pelvic inflammatory disease and HIV acquisition and transmission, though the underlying mechanisms are incompletely understood. We characterized the effect of TV and BV infection on inflammatory markers in the vagina among reproductive-aged women in Atlanta, Georgia. Cervicovaginal lavage specimens were collected from HIV seronegative women at a baseline visit and again three months later. Eighteen individual cytokines, 17 T-cell subsets, BV, and TV were measured at both timepoints. After natural log transformation, the median cytokine concentration and number of T-cells were compared by infection status statistically using the Kruskal-Wallis test. A cytokine inflammation score and a T-cell score were created using principal components analysis. The scores were then used as outcomes in separate linear mixed regression models with a random intercept. Sixty women had baseline data and 43 were seen for follow-up. The median age was 30 years, 78% self-reported Black race. TV and BV prevalence at the baseline visit was 15% and 37%, respectively. The concentration of 16 out of 18 cytokines differed by infection status. In multivariable modeling, neither TV nor BV were associated with cytokine score. Most CD4+ T-cell subsets (7 out of 9) differed by infection status. In a multivariable model, TV infection was associated with a higher T-cell score (1.54; 95%CI 0.00, 3.08). BV was not associated with a higher T-cell score. Increased concentration of vaginal mucosal T-cells may explain the observed association between TV infection and HIV risk.