Resistance to activated protein C and portal vein thrombosis: two cases and review of literature

Introduction. - Resistance to activated protein C is the most common inheri ted factor at the origin of deep venous thrombosis. As portal vein thrombos is is rare, causes such as cirrhosis, intra-abdominal infection, primary to hepatocellular carcinoma, myeloproliferative disorders or coagulation abno rmalities must be investigated. Exegesis. - We report two cases of portal vein thrombosis associated with r esistance to activated protein C. This association is not frequent, as only 12 cases have been reported in the literature. These studies show that res istance to activated protein C was rarely the only factor, as other prothro mbotic abnormalities were present in more than 70% of cases. Conclusion. - Resistance to activated protein C is rarely associated with p ortal vein thrombosis. When present, other causes should not be overlooked. The potential existence of resistance to activated protein C should be sys tematically investigated in case of either portal vein thrombosis in patien ts with personal or familial thrombosis history, association with multiple thrombosis, or when the disease etiology remains unknown. (C) 1999 Elsevier , Paris.