Total and free tissue factor pathway inhibitor in pregnancy hypertension

ObjectiveTo clarify the role played by tissue factor pathway inhibitor (TFPI) in pregnancy hypertension.MethodsUsing enzyme-linked immunosorbent assays, hemostatic measurements were obtained for women with pre-eclampsia (n = 51), nonproteinuric hypertension of pregnancy (n = 62), postpartum pre-eclampsia 24 h after childbirth (n = 31), and no hypertension (healthy pregnant controls, n = 100).ResultsThere was a significant increase in circulating free TFPI levels in women with pre-eclampsia (9.7 ± 6.2 ng/mL) or nonproteinuric hypertension of pregnancy (8.3 ± 5.3 ng/mL) compared with healthy controls (5.3 ± 2.1 ng/mL). In women with pre-eclampsia the levels remained elevated after placental delivery (10.6 ± 4.0 ng/mL). Free protein S levels were significantly higher in women with pre-eclampsia (40.0% ± 10.7%), nonproteinuric hypertension of pregnancy (37.1% ± 12.5%), or postpartum pre-eclampsia (39.3% ± 9.1%) than in healthy pregnant controls (32.2% ± 8.5%).ConclusionIncreased levels of the physiologically active free forms of TFPI and free protein S, 2 coagulation inhibitors, may protect women with pregnancy-induced hypertension from the risks of hemostatic activation.