Effectiveness of red blood cell exchange, partial manual exchange, and simple transfusion concurrently with iron chelation therapy in reducing iron overload in chronically transfused sickle cell anemia patients

BACKGROUNDChronic transfusion therapy (CTT) is indicated for stroke prevention in children with sickle cell anemia (SCA) and is complicated by iron overload and alloimmunization. CTT is performed by simple transfusion (ST), partial manual exchange (PME), or erythrocytapheresis (RCE). Although small case series have demonstrated RCE in combination with iron chelation therapy stabilizes and/or decreases ferritin, there are no reports comparing the effect of ST, PME, and RCE on liver iron concentration (LIC). CTT modality effect on serum ferritin and LIC were compared in SCA patients on iron chelation, with hemoglobin (Hb)S goal of 30%. STUDY DESIGN AND METHODSMedical records of SCA patients on CTT and deferasirox (25 mg/kg/day) were retrospectively reviewed. Mean HbS%, change in ferritin and LIC, and alloimmunization rate were determined for each CTT group. RESULTSTwenty-eight patients were included; six crossed over (one from ST to PME, one from ST to PME then to RCE, three from ST to RCE, and one from PME to RCE) to include 36 transfusion modality intervals. Median pretransfusion HbS% levels were 32.7% (ST), 36.2% (PME), and 34.7% (RCE; p=0.732). Median ferritin changes were +15 (-17 to +45), +38 (+24 to +105), and -91 (-141 to -48) ng/mL/month (p=0.003), and median LIC changes (available in 22 patient transfusion modality intervals) were +1.3 (-1.6 to +4.3), +2.3 (-6.5 to +8.9), and -5.7 (-10.7 to -0.5) mg/g/year (p=0.024) in ST, PME, and RCE, respectively. There was no significant difference in alloimmunization rate between ST/PME and RCE groups. CONCLUSIONWe recommend RCE plus chelation as an effective method for reducing iron overload, while maintaining HbS at 30% to 35%.