Fas and Fas ligand expression in maternal blood and in umbilical cord blood in preeclampsia

The Fas-Fas ligand (FasL) pathway of apoptosis is abnormally activated in d iseases associated with impaired immune tolerance or chronic inflammation. Pregnancy-related hypertension is a spectrum of disease that commonly cause s significant morbidity in women and in their newborn infants, is associate d with generalized inflammation, and may be causally related to impaired ma ternal-fetal tolerance. Our recent observation of enhanced trophoblast expr ession of FasL in one form of pregnancy-related hypertension led us to hypo thesize that this group of disorders might be associated with abnormal acti vation of the Fas-FasL pathway. To test this hypothesis, we prospectively q uantified soluble and leukocyte-associated Fas receptor and FasL in the mat ernal and umbilical cord blood (CB) sera of 20 gestations complicated by pr eeclampsia and of 18 normal control gestations, using ELISA and flow cytome tric analyses. We determined higher soluble FasL levels in paired maternal and CB sera of hypertensive gestations compared with control gestations (p < 0.01) in contrast, soluble Fas levels were similar between groups. Surfac e expression of FasL was lower on maternal (p < 0.01) and CB (p < 0.05) neu trophils from affected gestations, whereas surface Fas expression was lower on maternal (p < 0.02), but not CB, neutrophils and lymphocytes. We conclu de that expression of Fas and FasL in sera and on leukocytes is altered in gestations complicated by preeclampsia, and speculate that activation of th e Fas-FasL pathway mediates associated pathologic processes in affected wom en and in their neonates.