L-asparaginase-induced hypocomplementemia in acute lymphocytic leukemia (ALL) of childhood.

Serum complement studies were carried out in five children with acute lymphocytic leukemia. During therapy with L-asparaginase, prednisone and vincristine, hypocomplementemia developed in all patients, and disappeared within 2 weeks after the discontinuation of L-asparaginase. Complement breakdown products were not present in plasma. The changes of serum complement levels paralleled those of plasma fibrinogen. These findings suggest that the hypocomplementemia observed in these patients may be related to impaired protein synthesis induced by L-asparaginase.