Hypofibrinogenemia associated with vincristine and prednisone therapy in lymphoblastic leukemia.

Three patients with acute lymphoblastic leukemia and one with lymphosarcoma cell leukemia developed transient hypofibrinogenemia during a course of treatment with vincristine and prednisone. There was no evidence of overt, disseminated intravascular coagulation or significant liver impairment. Fibrinogen survival using homologous-125-I-labelled fibrinogen was measured in two patients; it was moderately shortened in both, perhaps indicating subclinical intravascular coagulation. Rapid lysis of leukemic cells might have been responsible for activating coagulation and fibrinolysis in vivo. These four patients, however, were not different in any clinical or laboratory parameter from nine others with lymphoblastic leukemia similarly treated and investigated without observing any defect in their fibrinogen. There were no bleeding complications and the fibrinogen level became normal within 13 to 30 days.