Erythrocytapheresis therapy to reduce iron overload in chronically
transfused patients with sickle cell disease
HC Kim, NP Dugan, JH Silber, MB Martin, E Schwartz, K Ohene-Frempong and AR Cohen
Children's Hospital of Philadelphia, Division of Hematology, PA 19104.
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.
Volume 83,
Issue 4,
pp. 1136-1142,
02/15/1994
Copyright © 1994 by The American Society of Hematology
