Antithrombin and antithromboplastin activity accompanying IgG myeloma. Report of a case with a severe bleeding tendency.

Four basic coagulation tests, the prothrombin time, thrombin time, partial thromboplastin time, and prothrombin consumption time, were used, with relatively simple modifications, to demonstrate the presence of two circulating anticoagulants in the blood of a patient with IgG myeloma and a severe bleeding tendency.