Leukapheresis and Exchange Transfusion in Children with Acute Leukemia and Hyperleukocytosis. A Single Center Experience

Background: The risk of severe complications or death during the initial period of acute leukemia was markedly decreased due to the progress in pediatric oncology and use of simple measures like hyperhydration, forced diuresis, treatment of hyperuricemia, correction of electrolyte and coagulation disturbances and the careful use of antileukemic drugs. The incidence of leukostasis and tumor lysis syndrome depends on absolute initial white blood cell counts and the underlying type of leukemia. Leukapheresis or exchange transfusion may improve the prognosis of high risk patients. Methods: Records of all pediatric patients who were newly diagnosed with acute leukemia between 1/1998 und 12/2008 were retrospectively reviewed for presence of hyperleukocytosis (white blood cell count >100 GPT/I) at diagnosis and subsequent leukapheresis or exchange transfusion in regards to the clinical outcome. Results: At diagnosis 11 (14%) of 77 children with acute leukemia (7 acute lymphoblastic leukemia/ALL; 4 acute myeloblastic leukemia/AML) had hyperleukocytosis. 4 patients (2 ALL, 2 AML) received exchange transfusion and 2 others (1 ALL, 1 AML) underwent leukapheresis. Marked cytoreduction was achieved in all patients within 24h after therapy initiation. There were no procedure-related adverse events. Symptoms due to hyperleukocytosis markedly improved after cytoreduction. Conclusion: Leukapheresis or exchange transfusion together with conservative management and specific oncological therapy may contribute to rapid leukocyte reduction with acceptable risk. The exact impact of leukapheresis or exchange transfusion on short and long term outcome in pediatric patients with acute leukemia and initial hyperleukocytosis has to be evaluated in future multicentre studies or by the formation of clinical registries.