Protein C and S Deficiency in Deep Vein Thrombosis Patients Referred to Iranian Blood Transfusion Organization, Kermanshah Mehrdad Payandeh, 1 Mohammad Erfan Zare, 1, 2 Atefeh Nasir Kansestani, 1, 2 Kamran Ma nsouri, 1, 3 Zohreh Rahimi, 1, 4 Amir Hossein Hashemian, 5 Ebrahim Soltanian, 6 Hoshang Yousefi, 6 1Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran 2Student Research Committee, Kermanshah University of Medical Scien ces, Kermanshah, Iran 3Department of Molecular Medicine, School of advanced Medical Technologies, Tehran University of Medical Sciences, Tehran, Iran 4Department of Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Ir an 5Department of Biostatistics, Faculty of Public Health, Kermanshah University of Medical Sciences, Kermanshah, Iran 6Research Center of Iranian Blood Transfusion Organization, Kermanshah, Iran Corresponding Author : Mohammad Erfan Zare, BSC student of M edical Lab Sciences. Medical Biology Research Center, P.O.Box: 1568, Sorkheh Lizheh, Kermanshah University of Medical Sciences, Kermanshah, Iran. E-mail :
[email protected] Tel: +98 831 4276473 Fax: +98 831 4276471 Abstract Introduction: Normal homeostas is system has several inhibitor mechanisms in front of the amplifier’s natural clotting enzyme to prevent fibrin clots in the vessels. The main inhibitors of coagulation pathway are antithrombin (AT), protein C and protein S. Patients with hereditary defic iency of coagulation inhibitors are susceptible to venous thromboembolism (VTE). One of the major clinical manifestations of VTE is deep vein thrombosis (DVT). The present study has investigated the frequency of protein C and S deficiency among DVT patients that by using of these results and results from our previous study; we determined the most important hereditary risk factors for DVT in the Kermanshah Province of Iran with the Kurdish ethnic background.