HEMOSTATIC ABNORMALITIES ASSOCIATED WITH MONOCLONAL GAMMOPATHIES

To confirm and expand previous observations about the association of m onoclonal gammopathies with hemostatic defects, a prospective evaluati on was made in 42 patients with lymphoplasmacytic disorders. The incid ence of bleeding complications was low, despite the diversity of abnor mal hemostatic tests observed in these patients. Patients with myeloma frequently had abnormal coagulation tests, including thrombin time (6 4%), fibrin degradation products (32%), platelet aggregation tests wit h different agonist (30% to, 55%), and bleeding time (22%). The lack o f platelet response to ristocetin and normal ristocetin cofactor activ ity in four patients with myeloma may suggest a Bernard-Soulier-type d efect. Serum viscosity was negatively correlated with platelet aggrega tion with collagen, ristocetin, and adenosine diphosphate. In patients with immunoglobulin myeloma, there was a positive correlation between an increased viscosity and a prolonged thrombin time. This study demo nstrates the wide variety of coagulation abnormalities in lymphoplasma cytic disorders, usually without significant clinical implications.