Hyperleukocytosis has a high morbidity index. The involvement of the respiratory or central nervous system and the metabolic derangements accompanying tumor lysis are responsible for early mortality. Standard care for acute hyperleukocytosis must include cytoreduction, proper supportive care, and prevention of tumor lysis. Hydration, alkalization, allopurinol, or urate oxidase should be started immediately. In patients with low platelet count of less than 20,000/mm(3), platelet transfusions should be given to prevent cerebral hemorrhage, as platelets do not add substantially to blood viscosity. Packed red blood cells must be given with caution as they can significantly increase blood viscosity. If the patient is hemodynamically stable, packed red transfusions should be planned when the hemoglobin level is less than 7-8 g/dl, avoiding post-transfusional levels above 10 g/dl. Coagulation abnormalities should be corrected. Leukapheresis has been advocated to correct metabolic abnormalities and to decrease viscosity by reducing the peripheral white blood count. However, leukapheresis may fail to decrease the leukocyte count substantially or may achieve only a transient tumor bulk reduction. The procedure is generally well tolerated but can involve problems such as the need for anticoagulation or difficulty of access, and limited availability in many institutions.Specific antileukemic therapy must be initiated as soon as life-threatening complications have been corrected as it remains the first-line treatment of hyperleukocytosis.
Keywords: Acute leukemia; Alkalization; Allopurinol; Hydration; Hyperleukocytosis; Leukapheresis; Rasburicase.