Diversity in cytokine response to bacteria associated with preterm birth by fetal membranes

Objective: This study compared cytokine and prostaglandin (PG) responses by fetal membranes stimulated with 4 different bacterial species associated with preterm birth (PTB). Study Design: Fetal membranes (n = 13 from normal term cesarean sections [not in labor]) in an organ explant system were stimulated with heat-killed Ureaplasma parvum, Gardanerella vaginalis, Escherichia coli, group B Streptococcus (GBS), or lipopolysaccharide (LPS). Cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]-α, and interferon-γ) and PG (PGF_2α and PGE₂) concentrations were quantitated and compared. Results: LPS and E coli increased all cytokine and PG productions compared with controls. Cytokine profiles were similar after G vaginalis and GBS stimulation. G vaginalis increased PGE₂, whereas GBS increased PGF_2α. U parvum demonstrated the mildest response with only IL-10 and TNF-α concentrations being higher with no detectible effect on PGs. Conclusion: Fetal membrane cytokine signatures of 4 different bacteria associated with PTB are distinct, suggesting that infection as a potential cause of PTB is not homogeneous in its presentation.