Bone marrow iron score as an indicator for secondary iron overload in acute myeloid leukemia patients

Objectives: Secondary iron overload due to red blood cell transfusions (RBCT) is associated with increased morbidity and mortality. However, attention for secondary iron overload and its side effects in patients with hematological malignancies may need improvement. The aim of this study was to determine the number of transfused RBCT needed to reach a maximum bone marrow iron score (BMIS). Methods: Bone marrow iron score was independently assessed by two researchers on consecutive bone marrow samples of 35 acute myeloid leukemia (AML) patients. The slides were blinded to both researchers to prevent bias. A Kaplan-Meier survival analysis was performed for estimation of the proportion of patients reaching a maximum BMIS. Results: In total, 141 bone marrow specimens from 35 patients were included. The median number of RBCT to reach a maximum was 20 units (range 6-42, IQR 15-26), after a mean of 1.64 chemotherapy courses (SD 0.99). Conclusions: In conclusion, the cumulative RBCT number is associated with BMIS. Due to the considerable variation in number of RBCT to reach a maximum BMIS, BMIS instead of only considering the cumulative RBCT number may be a valuable indicator of secondary iron overload in AML patients. BMIS could guide iron-lowering therapy and/or transfusion strategies in an early stage.