Management of Leukemoid Reaction

Treatment Strategy

The American Society of Hematology recommends hydroxyurea as the cytoreductive agent when symptomatic leukocytosis requires urgent reduction, with a dosing of 50-60 mg/kg per day until WBC decreases to 10-20 × 10⁹/L, for patients with symptoms of leukostasis 1, 2
The American Society of Hematology suggests reserving cytoreductive therapy for patients with symptoms of leukostasis, such as pulmonary infiltrates, neurologic symptoms, or hemorrhagic complications 1
The National Comprehensive Cancer Network advises avoiding excessive red blood cell transfusions until WBC is reduced, as this increases blood viscosity and risk of leukostasis complications 1, 2
The European Society for Medical Oncology recommends monitoring for tumor lysis syndrome if cytoreductive therapy is initiated, with aggressive hydration, allopurinol or rasburicase for uric acid control, and monitoring of urine pH and electrolytes 1, 2

The American Society of Hematology advises against initiating chemotherapy for leukemoid reaction, as this is a reactive process, not leukemia, and leukapheresis has no proven impact on long-term outcomes in leukemoid reaction and should not be routinely employed 1