Cryptogenetic liver cirrhosis and prothrombotic mutations - A mere association?

Thrombin activation and microthrombosis of intrahepatic portal venules is a common feature in liver cirrhosis, due in part to relative protein C deficiency and altered coagulation-anticoagulation-fibrinolysis balance. Extension of this microthrombotic process to larger portal vessels explains the increased incidence of portal vein thrombosis in liver cirrhosis. Thrombin not only leads to thrombosis, but also activates liver stellate cells and promotes fibrogenesis. Also, ischemia associated with thrombosis up-regulates the expression and secretion of growth factors involved in fibrogenesis. The coincidence in a given patient of prothrombotic mutations, such as factor V Leiden or PAI-1 polymorphisms, can accelerate the fibrogenetic process. We hereby present two cases of liver cirrhosis in which etiologic evaluation was negative except for the finding of a factor V Leiden mutation in one case and the 4G/5G PAI polymorphism in the second case. These observations support the hypothesis that these mutations may be involved in the etiology of some cases of cirrhosis, or, at least, accelerate the evolution of the disease. It is therefore convenient to search for the presence of prothrombotic mutations in patients with cryptogenetic cirrhosis.