CLINICAL ARTICLE Total and free tissue factor pathway inhibitor in pregnancy hypertension A.M. Abdel Gader a, ⁎ , A.A. Al-Mishari b , S.A. Awadalla a , N.M. Buyuomi a , T. Khashoggi b , M. Al-Hakeem b a The Coagulation Laboratory, Department of Physiology, College of Medicine and King Khalid University Hospital, Riyadh, Saudi Arabia b The Department of Obstetrics and Gynecology, College of Medicine and King Khalid University Hospital, Riyadh, Saudi Arabia Received 13 December 2005; received in revised form 21 July 2006; accepted 26 July 2006 Abstract Objective: To clarify the role played by tissue factor pathway inhibitor (TFPI) in pregnancy hypertension. Methods: Using 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). Results: There 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 post- partum pre-eclampsia (39.3% ± 9.1%) than in healthy pregnant controls (32.2% ± 8.5%). Conclusion: Increased 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. © 2006 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. KEYWORDS Plasminogen activator inhibitor (PAI); Pre-eclampsia; Pregnancy hypertension; Protein C; Protein S; Tissue plasminogen activator; Total and free tissue factor pathway inhibitor 1. Introduction Pregnancy hypertension (PH, traditionally called toxemia of pregnancy), the most prevalent preg- nancy complication [1], is divided into 3 categories: ⁎ Corresponding author. Tel.: +966 1 467 1042/468 3752; fax: +966 1 467 2549. E-mail addresses: amagader@ksu.edu.sa, amagader@hotmail.com (A.M. Abdel Gader). www.elsevier.com/locate/ijgo 0020-7292/$ - see front matter © 2006 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. doi:10.1016/j.ijgo.2006.07.014 International Journal of Gynecology and Obstetrics (2006) 95, 248–253