REGULATION OF THROMBIN TIME IN CIRRHOSIS

Standard coagulation profiles, plasmin and plasminogen activities, and measurements of antithrombin III and antithrombin II (heparin co-factor) activities were performed on 9 patients with biopsy-proven cirrhosis and on a 10th patient studied over a 30 min period for biopsy-proven cirrhosis associated with persistent hypofibrinogenemia. Prolongation of the thrombin time was observed in all 10 patients and was not correlated with fibrinogen concentrations, plasmin nor plasminogen activity, nor the appearance nor magnitude of fibrin-fibrinogen split product titers. There was a negative correlation between the presence of free plasma in these patients and the presence of magnitude of fibrin-fibrinogen split product titers. The 1 patient with persistent hypofibrinogenemia demonstrated consistently shorter prolongation of the thrombin time on all occasions despite lower fibrinogen levels, longer prothrombin and partial thromboplastin times, and higher plasmin and fibrin-fibrinogen split product concentrations than the 9 patients studied. This patient''s relative normalization of the thrombin time was most likely related to negligible antithrombin III and heparin cofactor activities, and suggests the significance of these antithrombins as possible regulators of the thrombin time in cirrhosis.