Leukapheresis is a procedure based on mechanical separation of leukocytes and it has been used in many hematological disorders such as Acute Myeloid Leukemia (AML). Concerning survival and the prevention of complications, it has shown heterogeneous results in multiple studies.

To present two cases in which leukapheresis was performed and yielded good results in terms of WBC reduction and preventing leukostasis complications.

Case 1 ‒ Man, 76 years old, presented with dyspnea, thoracic pain and decline of overall state, Complete Blood Count (CBC) showed: Hemoglobin (Hb) 7.7 g/dL, White Blood Count (WBC) 235,130 mm3 (94% blasts), platelets 28,000 mm3. Physical exam with signs of retinal leukostasis and hemorrhage. Blasts morphology was suggestive of AML and leukapheresis was performed. The procedure lasted 6 hours without any unforeseen consequences. Hydroxyurea (HU) was also initiated. WBC reduced to 57,610 mm3. Chemotherapy started 2-days after and there was complete symptomatic recovery. Case 2 ‒ Woman, 80-years old, presented with asthenia, weakness, headache, visual blurring, dyspnea and cutaneous and mucosal bleeding, CBC showed Hb 5.8 g/dL, WBC 181,400 mm3 (90% blasts), platelets 140,000 mm3. Physical exam also showed signs of retinal hemorrhage and leukostasis. Blasts morphology suggested myelomonocytic AML. Leukapheresis was performed and WBC reduced to 75,310 mm3, in concomitance HU was initiated. Chemotherapy started 3-days after and the patient was discharged, but 3-months after she presented acute cognitive disorientation and WBC was 290,000 mm3. Another leukapheresis session was performed but the patient progressed to death on the same day.

Leukostasis is a medical emergency, commonly observed in AML patients, and is associated with increased morbidity and mortality due to tissue hypoxia, tumor lysis syndrome and intracranial hemorrhage, the 1-week mortality can be as high as 40%. Rapid cytoreduction is indicated for symptomatic leukostasis patients as the ones described here. HU or other cytoreductive agents are useful temporizing measures. Although the benefits of leukapheresis versus cytoreductive agents alone remains poorly defined, therapeutic apheresis for AML remains as a recommendation grade 2B by the American Society for Apheresis, there so weak recommendation with moderate quality evidence. The role of leukapheresis as an adjunct therapy is controversial, therefore it is typically reserved for patients with leukostasis who must have induction chemotherapy postponed. It is known that therapeutic apheresis improves tissue perfusion with evidence of rapid reversal pulmonary and central nervous system manifestations, with some theoretical and practical limitations, but it can reduce the rate of early death, although there is no impact on later mortality or long term survival. The WBC can be reduced by 30% to 60%  in one single session; these results were seen in both reported cases.

Therapeutic apheresis is effective in reducing the peripheral blood leukocytes and in preventing leukostasis complications, therefore if facilities are available, it is a temporizing measure for rapid cytoreduction in symptomatic patients, as described through the reported cases.