revised January 4, 2001

Elliot Vichinsky M.D. Director, Hematology/Oncology Oakland Children's Hospital Oakland, California

Transfusions are indicated for either episodic events triggered by an acute complication or a necessary medical intervention (e.g., neurosurgery). In contrast to these episodic indications, some clinical problems require long-term suppression of circulating sickle cells. Chronic transfusion therapy usually achieves this goal.

Several methods of transfusion are available, including simple transfusion, partial exchange transfusion, or erythrocytapheresis. The method used depends on the specific indications. Except for episodes of severe anemia, pheresis offers many benefits and should be available to sickle cell patients.

After the decision to transfuse, several goals should be set, including final post-transfusion hematocrit, percent hemoglobin S desired, and type of red cells to be used. Hyperviscosity from simple transfusion is a dangerous problem in sickle cell patients, and must be avoided. The post-transfusion hematocrit should not exceed 36 percent. In general, limited phenotypically-matched, sickle-negative, leuko-depleted packed cells are the blood product of choice. Finally, there should be a comprehensive transfusion protocol, that includes accurate records, the patient's red cell phenotype, alloimmunization history, number of units received, serial hemoglobin S percentages, and results of infectious and iron overload monitoring results.

The antigenic phenotype of the red cells (at least ABO, Rh, Kell, Duffy, Kidd, Lewis, Lutheran, P, and MNS groups) should be determined in all patients older than 6 months of age. A permanent record should be maintained in the Blood Bank, and a copy of the record should be given to the patient or family. All patients with a history of prior transfusion should be screened for the presence of alloantibodies. The efficacy of a chronic transfusion regimen should be assessed periodically by determining the proportion of hemoglobin S by quantitative hemoglobin electrophoresis as well as the hemoglobin concentration or hematocrit.

The high prevalence of alloimmunization in patients with sickle cell disease likely has several causes. Lack of phenotypic compatibility between the donor and recipient doubtless is a major factor. All patients should receive limited phenotypic matching for antigens E, C and Kell. Extensive phenotypic matching is recommended for patients who have formed alloantibodies.

Pre-storage leuko-depletion of red cells is standard practice to reduce febrile reactions, platelet refractoriness, infections, and cytokine-induced complications. Washed red cells should be reserved for patients with a history of allergic reactions following transfusion.

Irradiated blood products should be considered in possible bone marrow transplantation candidates. Relatives should not be used as blood donors for children who could be candidates for bone marrow transplantation.

Autologous blood transfusions for patients with sickle cell disease should be avoided. Red cell substitutes are experimental and generally not indicated.

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Transfusion Therapy in Sickle Cell Disease

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