Erythrocytapheresis therapy to reduce iron overload in chronically transfused patients with sickle cell disease

Abstract

Abstract Chelation therapy with deferoxamine is effective in preventing the risk of transfusional iron overload, but treatment failure is common because of noncompliance. To reduce the transfusional iron load, we have evaluated longterm erythrocytapheresis in 14 subjects with sickle cell disease and stroke (11) or other complications (3) as an alternative to simple transfusion. Subjects were treated with erythrocytapheresis using the Haemonetics V50 (Haemonetics Corp, Braintree, MA) to maintain the target pretransfusion hemoglobin S (Hb S) level less than 50% for 6 to 71 months. The transfusional iron load and the donor blood usage were analyzed for a 6- to 36-month study period and were compared with similar data from a subset of 7 subjects previously treated with conventional (target Hb S < 30%) and modified (target Hb S < 50%) simple transfusion protocols. The effect of erythrocytapheresis on iron accumulation was determined by assessment of serum ferritin levels in the absence of iron chelation. The mean transfusional iron load and donor blood usage with erythrocytapheresis were 19 +/- 14 mg iron/kg/yr (range, 6 to 50) and 188.4 +/- 55.2 mL packed-red blood cells (RBC)/kg/yr (range, 107 to 281), respectively. Of 6 subjects receiving no iron chelation therapy, 5 maintained normal or nearly normal serum ferritin levels during 11 to 36 months of erythrocytapheresis. In comparison with conventional simple transfusion and modified simple transfusion, erythrocytapheresis reduced iron loading by 87% (P < .01) and 82% (P < .01), respectively, but increased donor blood usage by 23% and 73%, respectively. Subjects with pre-erythrocytapheresis Hb levels > or = 8.0 g/dL had lower iron accumulation (P < .001) and less donor blood usage (P < .005) than subjects with Hb levels < or = 8.0 g/dL. Although donor blood usage is increased in comparison with simple transfusion, long-term erythrocytapheresis markedly reduces or prevents iron accumulation. This form of transfusion therapy allows the cessation of iron chelation in well-chelated subjects and, if used as the initial form of transfusion therapy, may prevent long-term complications of sickle cell disease without risk of iron overload and the need for chelation therapy.