Time course of peripheral blood count recovery during induction chemotherapy for childhood acute lymphoblastic leukemia

摘要

Introduction: Children with newly diagnosed acute lymphoblastic leukemia (ALL) present withlow peripheral blood counts caused by bone marrow replacement. The recovery of countsduring induction chemotherapy is not well described.Material and methods: Records for 63 children with ALL were reviewed. Peripheralhematology blood counts during five weeks of induction chemotherapy were extracted, andthe time to partial recovery with safe counts and complete recovery with normal counts inthe three cell lines determined. The number of red cell and platelet transfusions, the numberof febrile episodes, and the number of days on intravenous antibiotics were counted.Results: Platelet recovery occurred early: median time to achieving counts 50/nL 14 days, tocounts 100/nL 16 days. Neutrophil recovery was relatively slow: median time to counts 0.5/nL18 days, to counts 1.0/nL 26 days. The time to partial recovery was shorter in high risk than inlower-risk treatment groups. Partial platelet recovery by day 15 indicated early recovery andlower morbidity. Complete platelet recovery day 15 was significantly associated with residualdisease 0.1% after four weeks. Lymphocyte counts showed a marked decrease in first twoweeks followed by a rise in the next three weeks; a count 0.35/nL on day 15 was associatedwith poor response.Conclusion: After starting chemotherapy for ALL, platelet recovery can be expected after two tothree weeks while neutrophil recovery lasts three to five weeks. Platelet and lymphocyte countsafter two weeks treatment may give an indication of residual disease after four weeks.