Preeclampsia is associated with decreased placental interleukin-6 production.
OBJECTIVE
The etiology of preeclampsia is poorly understood, but may involve abnormal fetal-maternal immunologic interactions. Interleukin-6 (IL-6) is a multifunctional immunologic cytokine that is normally produced by the placenta during pregnancy. Recent studies have shown that amniotic fluid IL-6 is decreased in pregnancies complicated by preeclampsia. Consequently, this study was designed to test the hypothesis that placental IL-6 production is decreased in preeclampsia.


METHODS
Placental explants from normal (N = 6) and preeclamptic (N = 6) pregnancies were cultured in vitro, and the media were sampled at 0, 2, 6, 16, 28, and 48 hours. Production rates of IL-6 were measured by enzyme-linked immunosorbent assay, and relative IL-6 mRNA expression was measured by Northern and dot blot analyses.


RESULTS
Production rates of IL-6 were 2.3-fold lower in preeclamptic placentas than in normal placentas, at 146 pg/microgram/hour versus 341 pg/microgram/hour (P < .05). However, relative steady-state IL-6 mRNA expression was identical in preeclamptic and normal placentas.


CONCLUSIONS
Placental IL-6 production is decreased in preeclampsia. The decrease in placental IL-6 production and secretion in preeclampsia is regulated by a post-transcriptional mechanism.
Kauma
S W
SW
Department of Obstetrics and Gynecology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA.
Wang
Y
Y
Walsh
S W
SW
D000293:Adolescent; D000328:Adult; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008431:Maternal-Fetal Exchange; D009924:Organ Culture Techniques; D010920:Placenta / Q000276:immunology*; D011225:Pre-Eclampsia / Q000276:immunology*; D011247:Pregnancy; D012333:RNA, Messenger / Q000096:biosynthesis; D012016:Reference Values; D013997:Time Factors; D014158:Transcription, Genetic
D015850:Interleukin-6; D012333:RNA, Messenger