Leukapheresis in Pediatric Acute Leukemia with Hyperleukocytosis: A Single Center Experience

Background: Hyperleukocytosis (HL) in pediatric acute leukemia is associated with increased morbidity and mortality. The indications for leukapheresis (LPH) in these patients remain unclear, and the use of LPH remains controversial. Objectives: This study aimed to review the clinical characteristics and outcomes of newly diagnosed leukemia patients with HL, comparing those who received LPH and those who did not. Methods: We analyzed clinical data from patients enrolled in frontline protocols for acute leukemia between 2017 and 2022. We documented adverse events within the first 30 days in patients with a white blood cell (WBC) count ≥ 100,000 cells/mm³ and reviewed their management. Treatment strategies included hyperhydration, administration of allopurinol or rasburicase, early induction chemotherapy (CT), and LPH. Results: Of 404 pediatric patients with newly diagnosed acute leukemia, 41 (10.1%) presented with HL (median WBC count: 136,000 cells/mm³; range HL: 101,000 - 844,000 cells/mm³). Leukapheresis was used in 9 of the 41 (13%) patients with HL. The median WBC count in patients who received LPH was 520,000 cells/mm³ compared to 158,800 cells/mm³ in those who did not (P = 0.01). Pulmonary leukostasis occurred in 2 patients, one of whom underwent LPH. No early deaths related to cerebral leukostasis, coagulopathy, or pulmonary leukostasis were observed in any patient within the first 30 days. The LPH procedure was well tolerated, with no reported complications. The time from presentation to the initiation of CT was similar between patients who received LPH and those who did not, with a mean of 17 hours versus 18 hours, respectively (P > 0.05). Tumor lysis syndrome (clinical or laboratory) was observed in 2 patients (23%) with LPH and 2 patients (6.25%) without LPH. Conclusions: The early morbidity and mortality often associated with HL in children with newly diagnosed acute leukemia can be avoided through conservative management, potentially reducing the need for LPH. However, LPH is a safe and well-tolerated procedure at our institution. It may be considered for patients with leukostasis when early induction CT is not feasible.