title: Elevation of amniotic fluid interleukin-4 concentrations in women with preterm labor and chorioamnionitis.
abstract: Preterm labor associated with intrauterine infection is characterized by increased amniotic fluid concentrations of various proinflammatory cytokines, including interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-8, and macrophage inflammatory protein-1alpha (MIP-1alpha). 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 infection matched with patients with chorioamnionitis (n = 8). Amniotic fluid concentrations of IL-4 and IL-2 were determined for each sample with a specific and sensitive enzyme-linked immunoassay. We found that women with infection-associated preterm labor and delivery had significantly higher concentrations 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.
authors.affiliation: Department of Obstetrics and Gynecology, University of Utah School of Medicine, Salt Lake City 84132, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Dudley
authors.forename: C
authors.initials: C
authors.lastname: Hunter
authors.forename: M W
authors.initials: MW
authors.lastname: Varner
authors.forename: M D
authors.initials: MD
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000737:chemistry*; D016022:Case-Control Studies; D002821:Chorioamnionitis / Q000150:complications / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis*; D007752:Obstetric Labor, Premature / Q000175:diagnosis* / Q000209:etiology; D011247:Pregnancy
chemical_list: D007376:Interleukin-2; D015847:Interleukin-4