Thrombotic risk factors and extent of liver fibrosis in chronic viral hepatitis.

BACKGROUND AND AIMS Thrombosis of the small intrahepatic veins has been suggested to trigger liver tissue remodelling. We evaluated the prevalence of multiple thrombotic risk factors and their association with the extent of fibrosis in chronic viral hepatitis. METHODS Ninety consecutive patients with chronic hepatitis B or C without malignancy, a history of venous thrombosis, or antiviral/immunosuppressive therapy within the last six months were included. Thrombophilic and coagulation factors were evaluated on the liver biopsy day. RESULTS One or more thrombotic risk factors were found in 68% and > or =2 factors in 37% of patients. Higher necroinflammatory activity was independently associated with higher prothrombin time (p=0.003), alanine aminotransferase level (p=0.011), and histological staging (p=0.018). Patients with staging scores of 4-6 compared with those with scores of 0-3 more frequently had deficiency of protein C (24% v 3%; p=0.007), antithrombin III (28% v 5%; p=0.005), and plasminogen (19% v 2%; p=0.03), and a trend for more frequent activated protein C resistance (8% v 0%; p=0.075). The presence of > or =1 significant thrombotic risk factor was observed in 11/25 (44%) patients with staging scores of 4-6 and in 6/65 (9%) patients with scores of 0-3 (p<0.001), being the only variable independently associated with advanced staging (odds ratio 2.4, p=0.02). CONCLUSIONS Thrombotic risk factors are frequently detected in patients with chronic viral hepatitis and the presence of > or =1 significant factor is associated with more advanced fibrosis. Whether the association of such thrombophilic conditions with advanced fibrosis is a primary or secondary phenomenon and whether their development in combination with local inflammation accelerate the progression of liver fibrosis need further evaluation.