Serum-soluble CD40 ligand in normal pregnancy and in preeclampsia

OBJECTIVE: Soluble CD40 ligand is a transmembrane protein shed from activated platelets that is involved in the activation of endothelial cells. Findings that estradiol (E2) has an inhibitory effect on inflammation and platelet function and that serum E2 levels are low in women with preeclampsia prompted us to investigate the association between soluble CD40 ligand and serum E2 levels in normal pregnancy and in preeclampsia. METHODS: A case-control single-center design was used. The sample included 22 women with severe preeclampsia, 22 matched normotensive pregnant women, and 22 nonpregnant women. Enzyme immunoassay was used to measure soluble CD40 ligand. RESULTS: Significantly higher levels of soluble CD40 ligand were detected in the nonpregnant women (23,767 ± 15,637 pg/mL) and in the women with preeclampsia (21,025 ± 45,386 pg/mL) than in the normotensive pregnant women (8,292 ± 5,926 pg/mL) (P = .026). No significant correlation between soluble CD40 ligand levels and E2 levels was observed. CONCLUSION: The higher levels of soluble CD40 ligand detected in women with preeclampsia may indicate an exaggerated activation of platelets and endothelial cells.