Childhood acute lymphoblastic leukemia with hyperleukocytosis at presentation

• Published in: Blood research Vol. 49; no. 1; pp. 29 - 35
• Main Authors: Kong, Seom Gim, Seo, Jung Ho, Jun, So Eun, Lee, Byung Ki, Lim, Young Tak
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Hematology; Korean Society of Blood and Marrow Transplantation; Korean Society of Pediatric Hematology-Oncology; Korean Society on Thrombosis and Hemostasis 01.03.2014; 대한혈액학회
• Subjects: Original; 병리학; Pediatric acute lymphoblastic leukemia; Hyperleukocytosis; Central nervous system hemorrhage
• ISSN: 2287-979X; 2288-0011
• DOI: 10.5045/br.2014.49.1.29

Hyperleukocytosis caused by acute lymphoblastic leukemia (ALL) is associated with early morbidity and mortality due to hyperviscosity arising from the excessive number of leukocytes.This study was designed to assess the incidence of hyperleukocytosis, survival outcomes, and adverse features among pediatric ALL patients with hyperleukocytosis. Between January 2001 and December 2010, 104 children with previously untreated ALL were enrolled at the Pusan National University Hospital. All of them were initially stratified based on the National Cancer Institute (NCI) risk; 48 (46.2%) were diagnosed with high-risk ALL. The medical charts of these patients were retrospectively reviewed. Twenty (19.2%) of the 104 children with ALL had initial leukocyte counts of >100×10(9)/L, and 11 patients had a leukocyte count of >200×10(9)/L. Male gender, T-cell phenotype, and massive splenomegaly were positively associated with hyperleukocytosis. Common early complications during induction therapy included renal dysfunction, and central nervous system hemorrhage. The complete remission (CR) rate for the pediatric ALL patients with hyperleukocytosis (94.1%) was similar to the overall CR rate (95.6%). The estimated 3-year event free survival (EFS) and overall survival of ALL children with hyperleukocytosis were 75.0% and 81.2%, respectively. However, patients with initial leukocyte counts >200×10(9)/L had a lower EFS than those with initial leukocyte counts 100-200×10(9)/L (63.6% vs. 100%; P=0.046). The outcome of pediatric ALL cases with an initial leukocyte count >200×10(9)/L was very poor, probably due to early toxicity-related death during induction therapy.