Enhanced Blood Coagulation and Fibrinolysis in a Patient with Primary Amyloidosis

Summary A case of primary amyloidosis associated with blood coagulation abnormalities is presented. Enhancement of coagulation, suspected because of acceleration of the thromboplastin activation test and of abnormal thrombelastography patterns, was confirmed by the presence of thrombi observed at necropsy. Increased systemic fibrinolysis was evidenced by accelerated clot lysis, increased euglobulin activity, and decreased plasminogen. The presence of fragmented red cells in the peripheral blood smear was consistent with a microangiopathic process. Despite these abnormalities, there were no major changes in levels of coagulation factors. Episodes of massive bleeding occurred when major changes in coagulation or fibrinolysis were absent, supporting the suggestion that vascular infiltration by amyloid is a major cause of hemorrhage.