Hyperleukocytosis, leukostasis and leukapheresis: practice management.

Hyperleukocytosis, arbitrarily defined in acute leukemia as a white blood cell count greater than 100,000/mL, often is associated with increased morbidity and mortality in patients with leukemic processes. It can induce leukostasis, tumor lysis syndrome and disseminated intravascular coagulopathy and has significant prognostic implications with or without one of these clinical complications. The main sites that tend to be injured from the obstructions are the central nerve system and lungs. Despite characteristic clinical presentations, the diagnosis of leukostasis is rarely made with high confidence. The main goal of the management of hyperleukocytosis and/or leukostasis is to reduce the white blood cell count before starting induction chemotherapy. The cytoreduction can be achieved by either leukapheresis and/or hyroxyurea. The technical aspects, complications and efficacy of leukapheresis are discussed in the current article.