Transfusion medicine
Transfusion reaction
Red blood cell alloimmunization

Topic Completed: 1 September 2011

Revised: 5 April 2019

Copyright: 2002-2019,, Inc.

PubMed Search: Red blood cell alloimmunization [title]

Huy Phu Pham, M.D., M.P.H.
Page views in 2018: 65
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Table of Contents
Definition / general
Cite this page: Pham HP Red blood cell alloimmunization. website. Accessed June 25th, 2019.
Definition / general
  • Red cell alloantibodies other than naturally occurring anti A or anti B are called unexpected red cell alloantibodies
  • Only occurs in patients with history of pregnancy, transfusion, transplantation
  • Appears to be regulated by CD4+ CD25+ T cells (Am J Hematol 2007;82:691)
  • Occurs in 3% of general population, 37% with thalassemia (Transfus Med 2006;16:200), 18 - 47% with sickle cell anemia (Transfusion 2002;42:37), 20% if prior transfusion but no hematologic or oncologic disease
  • Still occurs in pregnancy despite widespread antenatal and postpartum Rhesus immune globulin (RhIG), due to inadvertent failure to administer and antenatal sensitization prior to administration of RhIG (Semin Hematol 2005;42:169)
  • Incidence not affected by prestorage leukoreduction (Br J Haematol 2005;129:151)
  • Different antibodies appear at different times after transfusions (Transfusion 2006;46:250)
  • Usually no acute hemolytic transfusion reactions even if red cell antibodies present, if accurate antibody identification and component phenotyping occurs during compatibility testing
  • May cause transfusion challenges in solid organ transplant patients (Transplantation 2007;84:527)
  • Recommended to match red cells for E antigens in thalassemia patients (Southeast Asian J Trop Med Public Health 2006;37:1015)
  • Alloimmunization may be reduced by molecular testing (Curr Opin Hematol 2006;13:471, Transfusion 2006;46:841)
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