The Effect of Iron Overload on the Mobilization of Peripheral Blood Hematopoietic Stem Cells in Pediatric Patients with Thalassemia Major

Abstract

Introduction: The purpose of this study was to examine the effect of iron overload on the mobilization of peripheral blood stem cells (PBSCs) in pediatric patients with β-thalassemia major (TM). Methods: We retrospectively reviewed the records of 226 patients with TM from whom PBSCs were collected. Iron overload was based on serum ferritin level, and liver and cardiac iron overload was measured by magnetic resonance imaging (MRI) T2*. Results: The mean age of the TM patients was 7.35 ± 3.41 years. Of the patients, only 171 received MRI. Of the 171 patients, 35 had normal liver iron levels, 39 mild liver iron overload, 90 intermediate liver iron overload, and 7 severe liver iron overload. The intermediate + severe group was associated with significantly higher age and BMI and lower leukapheresis product white blood cell count and CD34⁺ cell levels (all, p < 0.05). Conclusion: Leukapheresis indices were similar between patients with different degrees of iron overload according to the ferritin level and cardiac iron overload, in which the later might be due to the small number of patients with cardiac overload. In patients with TM, the intermediate and severe liver iron overload was associated with poorer mobilization of PBSCs.