REDUCING THE RISKS OF BLOOD TRANSFUSION THERAPY
The immediate goal of blood transfusion therapy is to relieve anemia and improve tissue perfusion while avoiding complications which, after repeated transfusions, include iron overload. The benefits of blood transfusion therapy for selected patients are well established. It has been shown to dramatically extend survival among patients with thalassaemia major [1;2] and to reduce the yearly risk of strokes among children in the USA with SCD by as much as 92% [3].
Blood transfusion therapy is essential in the treatment of these diseases, but iron overload remains an issue that requires careful management. One strategy to reduce the risk of iron overload is the judicious timing of blood transfusions. Fewer blood transfusions mean the patient accumulates less iron at a slower rate. Such management, however, merely delays the onset of iron overload and is insufficient for prevention. The use of effective iron chelation therapy becomes increasingly important as patients receive an increasing number of blood transfusions.
PRACTICAL STEPS TO REDUCE THE RISKS ASSOCIATED WITH BLOOD TRANSFUSION THERAPY
The risks of alloimmunization, viral infections and iron overload can be minimized by following a number of practical steps:
- Alloimmunization can be reduced, or its impact lessened, through typing and cross matching blood transfusion products, with extended typing as indicated [4].
- Viral infections can be prevented by screening blood products prior to transfusion.
- In chronically transfused patients, monitoring for iron overload should be performed. The most common methods are the measurement of serum ferritin levels or liver iron levels by biopsy or Magnetic Resonance Imaging (MRI).
- Iron chelation therapy may be required after 10-20 blood transfusions, when serum ferritin levels exceed 1000 ng/mL [2].
  References
(1) Olivieri NF, Nathan DG, MacMillan JH, Wayne AS, Liu PP, McGee A, Martin M, Koren G, Cohen AR: Survival in medically treated patients with homozygous β-thalassemia. N Engl J Med 1994; 331(9):574-578.
(2) Porter JB: Practical management of iron overload. Br J Haematol 2001; 115(2):239-252.
(3) Adams RJ, McKie VC, Hsu L, Files B, Vichinsky E, Pegelow C, Abboud M, Gallagher D, Kutlar A, Nichols FT, Bonds DR, Brambilla D: Prevention of a first stroke by transfusions in children with sickle cell anemia and abnormal results on transcranial Doppler ultrasonography. N Engl J Med 1998; 339(1):5-11.
(4) Havemann H, Lichtiger B: Identification of previous erythrocyte alloimmunization and the type and screen at a large cancer center. A 4-year retrospective review. Cancer 1992; 69(1):252-255.
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