Thrombosis in children receiving L-asparaginase. Determining patients at risk.

Purpose: A prospective study of coagulation in 15 children who received L-asparaginase, vincristine, or prednisone plus or minus an anthracycline as part of a treatment program for leukemia or leukemia-lymphoma syndrome was conducted.

Patients and methods: One patient developed a central nervous system thrombosis.

Results: The inhibitors of coagulation, including antithrombin-III, protein C, protein S, and plasminogen, were decreased in many individuals, but were not significantly different in the patient who had experienced the thrombotic event. Platelet aggregations to low molar ADP were performed in four patients, and in three patients showed a hyperaggregable pattern.

Conclusions: The patient with thrombosis developed a transient acquired type II pattern on multimeric analysis of the von Willebrand factor, which was not seen in the other individuals studied.