Spontaneous and induced release of prostaglandins, interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha by placental tissue from normal and preeclamptic pregnancies

The objective of this study was to clarify the role of the main proinflammatory cytokines (interleukin [IL]-1, IL-6, tumor necrosis factor [TNF]-alpha) in the pathogenesis of preeclampsia and how these cytokines affect one another and the production of prostaglandins (PGs). The concentrations of cytokines and PGs in supernatants of placental tissue from preeclamptic and normal women were determined by enzyme-linked immunosorbent assay. The concentrations of the PGs from unstimulated preeclamptic placental tissue were significantly higher compared to the concentrations of PGs from normal unstimulated placental tissue. Significant levels of IL-1beta were observed only in the supernatants of preeclamptic placental tissue. Of interest, an increase in TNF-alpha production was detected in the supernatants of IL-1-stimulated preeclamptic placental tissue. The overproduction of TNF-alpha may be related not only to the effect of a stimulant like IL-1beta, but mainly to the lack of mechanisms down-regulating the production of TNF-alpha.