Cytokine expression in the placenta. The role of interleukin 1 and interleukin 1 receptor antagonist expression in chorioamnionitis and parturition.
Interleukin 1 (IL-1) is known to be present in placental tissue and is implicated as an endogenous mediator of inflammation and parturition. This study was undertaken to assess the role of IL-1 receptor antagonist (IL-1ra) in the placenta. Placentas with acute chorioamnionitis, with meconium staining, and without significant inflammation were examined for immunohistochemical expression of IL-1 and IL-1ra. Interleukin 1 and IL-1ra immunoreactivity was variably noted in the amnion, trophoblast, vascular smooth muscle, stromal cells, fibrinoid, and decidua in all placentas. Interleukin 1 immunoreactivity was less intense than IL-1ra immunoreactivity, and both were generally more intense in acute chorioamnionitis. Interleukin 1 receptor antagonist was detected (approximately 5 to 6 ng/mL) in the amniotic fluid of pregnant women at term. Colocalization of IL-1 and IL-1ra in normal and inflamed placentas suggests that the balance between these proinflammatory and anti-inflammatory mediators plays a role in parturition as well as in the pathogenesis of acute inflammation. An increase and/or imbalance in the IL-1 and IL-1ra expression associated with chorioamnionitis may precipitate preterm labor.
Baergen
R
R
Department of Pathology, University of California, School of Medicine, San Diego 92103-8720.
Benirschke
K
K
Ulich
T R
TR
D000293:Adolescent; D000328:Adult; D002821:Chorioamnionitis / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007375:Interleukin-1 / Q000378:metabolism*; D007743:Labor, Obstetric / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors*; D013194:Staining and Labeling
D016207:Cytokines; D007375:Interleukin-1; D017472:Receptors, Interleukin-1