Therapeutic leukapheresis for hyperleukocytosis in acute myelocytic leukemia.

Twenty-two patients with newly diagnosed acute myelocytic leukemia (AML) and white cell counts (WBC) greater than 100,000/microliters received one, two, or three leukaphereses prior to induction chemotherapy with cytosine arabinoside (Ara-C) and daunorubicin (DNR). Fifteen of 22 (68%) achieved a complete remission. Greater than a 30% decrease in initial WBC was found to be an important predictor of response. Fifteen of 17 patients (88%) with greater than 30% reduction of initial WBC achieved remission, while none of 5 patients with less than a 30% reduction responded (P = 0.001).