Allogeneic hematopoietic stem cell transplantations in acute lymphoblastic leukemia in children and adolescents

Abstract

Background. ALL is the most common indication for allogeneic hematopoietic stem cell transplantation (allo- HSCT) in children. Objective. The analysis of results of therapy in children and adolescents treated for ALL with allo-HSCT. Patients and methods. A total number of 41 patients undergoing allo-HSCT due to ALL between 2003 and 2012. In 17 patients HSCT was performed from related donor and in 24 from unrelated donor. A source of hematopoietic stem cells was peripheral blood in 21 patients, bone marrow in 18 patients and cord blood in 2 patients. Results. At present, 27 (65.8%) patients stay alive. Among 14 deaths, 8 were regarded as transplant-related mortality, and 6 as a relapse of disease. Transplant-related mortality was 8/41 (19.5%), including 7 (17%) in early posttransplant period (before day +100). Probability of survival for all patients was: pDFS=0.652±0.091 (mean disease-freesurvival was 3.8 years, 95%CI=2.7-4.8), pOS=0.630±0.080 (mean survival 3.9 years, 95%CI=3.0-4.8). The only factor predicting overall survival was time of pre-transplant relapse: for very early relapses pOS=0.333±0.157, for early relapses pOS=0.666±0.272 and for late relapses pOS=0.833±0.152 (p=0.010). Conclusions. Allo-HSCT from well-matched unrelated donors or genoidentical sibling donors is an effective treatment with acceptable toxicity in pediatric ALL. Precise HLA typing and matching resulted in a low incidence of acute and extensive chronic GVHD which is an important achievement for the quality of life in children and adolescents. The results from this study demonstrate the feasibility of a harmonized HSCT approach in pediatric ALL.