Therapeutic cytoreduction in a 7-month-old baby with acute leukemia.

A 7-month-old girl with acute biphenotypic leukemia [t(4;11)] had accompanying anemia, thrombocytopenia, and a white blood cell count of 535,000/microL with 98% blasts. Before instituting chemotherapy, therapeutic leukapheresis was done to reduce the threat of complications from leukostasis. Using a Cobe Spectra blood cell separator primed with modified blood, we processed 1,395 mL of her blood, removing 201 mL of the buffy coat containing 5.8 x 10(10) white blood cells. This reduced the WBC count to 301,000/microL. Only a single procedure was done, without significant complications. The rationale of this preparatory cytoreduction is discussed critically. Subsequent chemotherapy resulted in a long-lasting remission.