Objective: To investigate the association between a tumor necrosis factor-alpha (TNF-alpha) gene polymorphism, vaginal TNF-alpha level, and microbial flora in pregnant women.
Methods: Vaginal samples from 203 women at 18-22 weeks' gestation were analyzed for microflora. TNFA-308G>A polymorphism was analyzed by polymerase chain reaction and restriction endonuclease analysis and TNF-alpha concentration was determined by ELISA. Outcome data were subsequently obtained.
Results: The vaginal TNF-alpha concentration was elevated in TNFA-308A carriers only in the presence of abnormal vaginal flora. A median TNF-alpha level of 10.94 pg/ml in TNFA-308A carriers with bacterial vaginosis (BV) was significantly higher than that of 1.77 pg/ml in TNFA-308A carriers without BV (P=.02), and 1.72 pg/ml in TNF-308G homozygotes with BV (P=.01).
Conclusion: The TNFA-308G>A polymorphism influences the local TNF-alpha response to altered vaginal microflora. This suggests that the nature of the host response to microbial invasion in the lower female genital is genetically determined.