Blood Transfusion in Adult Patients with Sickle Cell Disease: Incidence of Alloimmunization

Background:

Chronic red blood cell transfusion has been proven to be effective in prevention of strokes, silent cerebral infarcts, acute chest syndrome, recurrent priapism and in pregnancy. The use of regular transfusions to mitigate other morbidities of sickle cell disease (SCD) is evolving. In the silent infarct transfusion (SIT) trial in children, chronic transfusion lead to a significant improvement in quality of life. Some of the common reasons patient with SCD do not get chronic transfusion is fear of alloimmunization, iron over load and risk of viral infections. We did a retrospective analysis of adult patients with SCD who need chronic blood transfusion to determine the incidence of alloimmunization. At our institute all pediatric sickle cell patients needing chronic transfusion are placed on protocol, receive C, E, and K matched blood, and remain on the protocol until they become adults.

Methods:

We electronically collected data from 180 adult SCD patients who need chronic transfusions and analyzed the data for the number of transfusions received, incidence of allo- immunization and most common antibodies identified.

Results:

A total of 3967 red blood cell transfusions were administered on 180 adult sickle cell disease patients. Twenty five patients developed antibodies (13.8 %). Fifteen out of the 25 had multiple antibodies (60%). The alloantibodies identified were : anti- K(11), anti- E(12), anti- Fy^a(5), anti-C (4), anti-V (4), anti- S (3), anti-D (2), anti- Jk^b (1), anti-Js^a(1) , and anti- Lutheran^a (3). Two patients had cold and 5 patients had warm autoantibodies.

Conclusion:

The policy to place patients with SCD needing chronic transfusion on protocol to receive C, E, and K matched red blood cells has decreased the alloimmunization rate to 13.8 %. We conclude that, fear of alloimmunization should not preclude physicians from using chronic red cell transfusions to prevent complications in sickle cell disease.