Regulation of interleukin 8 production in the term human placenta during labor and by antigestagens

OBJECTIVE: Our purpose was to assess the effects of labor and antigestagens on production of interleukin 8 by the term human placenta and to localize interleukin 8 in first- and third- trimester placentas. STUDY DESIGN: The study was conducted by the Department of Obstetrics and Gynaecology of the University of Edinburgh. Five placentas were collected after spontaneous and cesarean deliveries. Explants were cultured in the presence of mifepristone, lilopristone, or onapristone. The production of interleukin 8 was determined by specific radioimmunoassay, and the immunolocalization of interleukin 8 was determined in sections of first- and third-trimester placentas. RESULTS: All explants produced interleukin 8. Production was significantly increased (P<.05) after spontaneous delivery. In placentas delivered spontaneously, onapristone significantly increased production of interleukin 8 (P<.05), whereas in those from cesarean deliveries lilopristone caused a significant increase in production (P<.05). In the third-trimester placenta interleukin 8 was localized in the perivascular area of fetal vessels. In first-trimester villi it was peripherally located in syncytiotrophoblast. CONCLUSION: The human placenta at term is capable of producing interleukin 8, which is localized around the perivascular area of the villi. Production is increased after spontaneous labor and to varying degrees by the antigestagens studied. Interleukin 8 may have a role in the onset of parturition by recruiting and activating neutrophils at the placental site.