Partial manual exchange reduces iron accumulation during chronic red cell transfusions for sickle cell disease

Iron overload is an inevitable consequence of chronic red cell transfusions without erythrocytapheresis or chelation therapy. The effectiveness of partial manual exchange, a technique used to slow iron loading, has not been evaluated. We evaluated all children with sickle cell disease (SCD) receiving chronic transfusion to identify chelation-naive subjects who had quantitative liver iron concentration (LIC) studies. Seventeen chelation-naive children with SCD received a median of 29 transfusions before first LIC determination. Serum ferritin concentrations were assessed before each transfusion. The mean volume of blood phlebotomized before each transfusion was 5.1±1.8 mL/kg, which cumulatively resulted in a calculated median of 35.0 mg/kg iron removal. Using linear regression, pretransfusion phlebotomy resulted in a statistically significant reduction in ferritin (-8.8 ng/mL of ferritin for each mg/kg of iron phlebotomized, P=0.02). A reduction in LIC from pretransfusion phlebotomy could not be established (P=0.4). Partial manual exchanges appear to be an effective strategy for slowing the pace of iron loading in the setting of chronic transfusion for SCD.