Preterm labor associated with intrauterine infection is characterized by increased amniotic fluid concentrations of various proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (THF-α), (IL- 6, IL-8, and macrophage inflammatory protein-1α (MIP-1α). The purpose of this study was to determine if preterm labor in women with clinically evident chorioamnionitis is marked by elevations of the anti-inflammatory cytokine interleukin-4 (IL-4) and the T cell growth factor IL-2. Amniotic fluid samples were obtained from (1) women at term, not in labor (n = 10); (2) women at term, in labor (n = 10); (3) women with preterm contractions but undelivered within 1 week of amniotic fluid collection (n = 10); (4) women with preterm labor and delivery without clinically evident chorioamnionitis (n = 10); (5) women with preterm labor associated with chorioamnionitis (n = 8); and (6) women with preterm labor and delivery without matched with patients with chorioamnionitis (=8). Amniotic fluid concentrations of IL-4 and IL-2 were determined for each sample with a specific and sensitive enzyme-liked immunoassay. We found that women with infection-associated preterm labor and delivery had significantly higher concentration of IL-4 when compared to appropriately matched controls (p < 0.05). Additionally, women with preterm labor and delivery not associated with infection had higher amniotic fluid IL-4 concentrations than women with preterm contractions but no labor (p < 0.05). Women with term labor had rare modest elevations of amniotic fluid IL-4. No IL-2 was detected in any sample. Our data indicate that amniotic fluid IL-4 is elevated in women with preterm labor and delivery, particularly in association with chorioamnionitis. We suggest that IL-4, although previously considered an anti-inflammatory agent, may have a paradoxical proinflammatory role in the pathogenesis of infection- associated preterm labor.
- amniotic fluid
- preterm labor
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Obstetrics and Gynecology