Gelsolin down-regulates lipopolysaccharide-induced intraamniotic tumor necrosis factor-alpha production in the midtrimester of pregnancy.

OBJECTIVE: The purpose of this study was to identify gelsolin in midtrimester amniotic fluid and evaluate its interaction with lipopolysaccharide (LPS). STUDY DESIGN: Supernatants from 40 midtrimester amniotic fluid samples were incubated with Escherichia coli LPS, and gelsolin binding was measured by enzyme-linked immunosorbent assay. Unfractionated aliquots of 25 of the fluids were cultured ex vivo for 24 hours in the presence of LPS and supernatants tested for tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 production, and the influence of antigelsolin antibody was evaluated. RESULTS: Each amniotic fluid was positive for gelsolin that bound to LPS. LPS-induced TNF-alpha production was inversely proportional to the amniotic fluid concentrations of LPS-bound gelsolin (r = -0.5047; P = .006). Preincubation with monoclonal antibody to gelsolin led to an increase in LPS-induced TNF-alpha production (P = .01). There was no relationship between gelsolin and IL-10 production. CONCLUSION: Gelsolin is present in midtrimester amniotic fluid, binds to LPS, and inhibits the induction of TNF-alpha.

Differential expression of immune system-related components in midtrimester amniotic fluid from singleton and twin pregnancies.

OBJECTIVE: We investigated differences between singleton and twin gestations in immune mediators in midtrimester amniotic fluid. STUDY DESIGN: Amniotic fluid from 252 singleton and 46 twin gestations were tested by enzyme-linked immunosorbent assay for interleukin-1beta, interleukin-1 receptor antagonist, interleukin-4, tumor necrosis factor-alpha, nitric oxide, Clara cell protein 16, leptin, and the 70-kDa heat shock protein. A subset of amniotic fluid was also tested for leukemia inhibitory factor, angiogenin, and migration inhibitory factor-related protein 8 and migration inhibitory factor-related protein 14. Data were analyzed by the Mann-Whitney U test and Spearman rank correlation. RESULTS: Median concentrations of interleukin-1beta, tumor necrosis factor-alpha, interleukin-4, Clara cell protein 16, leptin, and angiogenin were increased in amniotic fluid from twins; median levels of the 70-kDa heat shock protein, leukemia inhibitory factor, migration inhibitory factor-related protein 8, and migration inhibitory factor-related protein 14 were highest in amniotic fluid from singletons (P < .001). CONCLUSION: Elevated levels of immune activators may contribute to the increased rate of preterm premature rupture of membranes and spontaneous preterm birth in twin populations.