A retrospective study was undertaken comparing the frequency and severity of anaphylactic reactions to E. coli-derived and Erwinia-derived asparaginase given intravenously on a weekly dosage schedule. Both drugs were found to produce life-threatening hypersensivity reactions with the chance of reaction per dose administered being almost identical--8% for each dose administered. Eleven of 31 patients (35%) experienced anaphylactic reactions, 9/27 (33%) with E. coli and 3/10 (30%) with Erwinia asparaginase, with one patient suffering anaphylaxis to both preparations. A marked increase in the percentage of patients having reactions occurred after the fourth dose of either preparation, with the incidence per dose increasing from 3.3% with the first dose to 32% on the fifth and subsequent doses. Rationale for an antibody-mediated allergic reaction is presented to explain the data.

The early detection and treatment of two cases of acute monocytic leukemia (AMoL) was hampered by the presence of positive slide tests for infectious mononucleosis (IM). This assumes great importance with the recent development of specific therapy, effective for certain subtypes of nonlymphocytic leukemia.