Disseminated intravascular coagulation and decrease in fibrinogen levels induced by vincristine/prednisolone therapy of lymphoid blast crisis of chronic myeloid leukemia.
Therapy with vincristine (2 mg i.v. weekly) and prednisolone (100 mg p.o. daily) caused a decrease in fibrinogen levels in nine patients treated for lymphoid blast crisis LBC) of chronic myeloid leukemia (CML). During the first days of treatment disseminated intravascular coagulation (DIC), evidence by a positive ethanol gelation test, markedly increased thrombin-antithrombin III complex and fibrin-split product D-dimer levels, and a rapid fall in fibrinogen levels was observed in two patients. The induction of DIC in these two patients caused profuse bleeding in one and necessitated substitution therapy with fibrinogen and platelet concentrates. The remaining seven patients revealed no signs of DIC; nevertheless, four of them showed a moderate increase in D-dimer levels after initiation of therapy. In these patients a well-known side effect of long-term steroid therapy, namely a decrease of fibrinogen levels, was observed within the first week of treatment. Fibrinogen levels did not fall below 150 mg/dl and increased after dose reduction from 100 mg/day to 50 mg/day. We conclude from our results that two types of disturbances in fibrinogen metabolism can be observed during vincristine/prednisolone therapy of LBC of CML: (a) a decrease of fibrinogen levels due to a steroid-mediated impairment of liver synthesis, and (b) a rapid fall in fibrinogen levels in the course of DIC, most likely induced by the release of procoagulants from deteriorating blast cells, leading to severe bleeding in selected cases.