Hemostasis disorders in monoclonal gammopathies

: The authors investigated haemostatic parameters of 43 patients with monoclonal gammapathy with principal diagnosis of multiple myeloma (MM-35), non-Hodgkin's lymphoma (NHL-3), M. Waldenstrom (3) and monoclonal gammapathy of undetermined significance (MGUS-2). Primary haemostasis defect was found in 24 patients. With the exception of 2 thrombocytopenic patients, the defect of aggregation, procoagulant activity and retraction is supposed to be caused by paraprotein. The examination of the 14C 5-HT release and TX B2 synthesis in thrombocytes showed, that platelet activation is unaffected and the paraprotein interferes with interactions of thrombocytes or with coagulation system. In plasma coagulation system explicit abnormalities were found only in thrombin time in 12 patients. The more detailed examination disclosed, that the defect resulted from paraprotein interference with fibrin monomer polymerisation. The thrombin proteolytic activity remained unaffected. In 3 patients shortened euglobulin lysis time was observed. Laboratory haemostasis defect was found in 26 patients (60%), however, the bleeding symptoms manifested in 5 cases (11%) only. The analysis of study results showed, that the most important abnormalities leading to overt bleeding are thrombocytopenia or combined haemostasis defect. Isolated laboratory defects remained silent in most cases.