Differential Vaginal Expression of Interleukin-1 System Cytokines in the Presence ofMycoplasma hominisandUreaplasma urealyticumin Pregnant Women

Abstract

Objective:The genital mycoplasmas,Ureaplasma urealyticumandMycoplasma hominis, are commonly identified in the vagina of healthy pregnant women. However, these microorganisms are the most common isolates from the amniotic fluids of women in preterm labor. The mechanisms responsible for vaginal colonization and ascent to the uterus remain undetermined. We evaluated the association betweenU. urealyticumandM. hominisvaginal colonization and the presence of pro-inflammatory and anti-inflammatory interleukin-1 system components in asymptomatic pregnant women of different ethnicities.Methods:Vaginal specimens, obtained from 224 first trimester pregnant women, were assayed for interleukin- 1β(IL-1β) and IL-1 receptor antagonist (IL-1ra) concentrations by ELISA.U. urealyticumandM. hominisvaginal colonization were identified by polymerase chain reaction (PCR).Results:Vaginal colonization withM. hominiswas identified in 37 (16.5%) women, and was more prevalent in black (18.9%) and Hispanic (20.9%) than in white (4.2%) women (p= 0.01).U. urealyticumwas present in 84 (37.5%) women and there was no ethnic disparity in its detection.M. hominiscolonization was associated with elevated median vaginal IL-1βconcentrations in both black women (p=0.02) and Hispanic women (p= 0.04), and was unrelated to vaginal IL-1ra concentrations. In marked contrast,U. urealyticumcolonization was associated with elevations in vaginal IL-1ra levels, but not with IL-1βconcentrations, in black women (p= 0.02) and Hispanic women (p< 0.0001) and marginally in white women (p= 0.06).Conclusion:M. hominiscolonization in healthy pregnant women is associated with localized pro-inflammatory immune activation, whileU. urealyticumcolonization is associated with immune suppression.