Neutrophils are stimulated by syncytiotrophoblast microvillous membranes to generate superoxide radicals in women with preeclampsia

Objective This study was undertaken to determine whether syncytiotrophoblast microvillous membranes (STBMs) stimulate maternal neutrophils to produce superoxide radicals in women with preeclampsia. Study design Serum levels of tissue polypeptide antigen (TPA), which is a marker for STBM, were measured in 25 nulliparous women (10 with mild preeclampsia, 6 with severe preeclampsia, and 9 controls). Superoxide production by maternal neutrophils from cases and controls and by donor neutrophils cocultured with the STBMs from cases and controls was measured spectrophotometrically by reduction of ferricytochrome C. Results Maternal TPA levels were significantly greater among cases than controls (P = .005). Superoxide production by maternal neutrophils and donor neutrophils cultured with STBM from cases of preeclampsia was greater than controls (P values .006 and .019, respectively), and dose-response relationships were observed. Superoxide production by maternal leukocytes was correlated with superoxide induction by STBMs in culture (P = .007). Conclusion STBMs in maternal blood induce neutrophils to generate superoxide radicals that may cause endothelial dysfunction in women with preeclampsia.