Tumor necrosis factor-alpha is decreased in the umbilical cord plasma of patients with severe preeclampsia

We investigated the role of the fetal immune system in pregnancies complica ted by preeclampsia by assessing umbilical cord plasma levels of the cytoki nes tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 be ta). Nineteen nulliparous patients with severe preeclampsia composed the st udy group (group A). A comparison group was comprised of 19 healthy nullipa rous patients with uneventful pregnancies (group B). Mixed umbilical cord b lood was collected immediately after delivery. Plasma was prepared and all samples were assayed for TNF-alpha and IL-1 beta by specific enzyme-linked immunoassays (ELISAs). Data are presented as the median with range of value s. The length of labor was similar in both groups. TNF-alpha was detected l ess frequently in the umbilical cord plasma of preeclamptic patients than i n the umbilical cord plasma of control patients (57.9 vs. 89.5%, p < 0.05), and the concentrations of TNF-alpha, were significantly lower in the umbil ical cord plasma of the preeclamptic patients [20 pg/ml (0-80 pg/mL) vs. 50 pg/mL (0-310 pg/mL), p < 0.05]. Umbilical cord plasma IL-1 beta detection rates and concentrations from the preeclamptic and control patients were si milar, [15.8 vs. 5.3%, 0 pg/mL (0-40 pg/mL) vs 0 pg/mL (0-10 pg/mL)]. The l ower concentrations of TNF-alpha in umbilical cord plasma of patients with severe preeclampsia suggest that release of TNF-alpha by the fetus and moth er are independent and may reflect adaptation of the fetus to reduced place ntal perfusion in preeclampsia.