An immunohematologist in Hungary reports that her center is currently considering a policy of whether or not to routinely perform Rhesus and Kell phenotype matching of donor RBC units as a prophylactic strategy to avoid red cell alloimmunization. She is aware that such a strategy is employed by many institutions as a prophylactic measure for non-alloimmunized patients with sickle cell disease and thalassemia, but she wonders if such a strategy should be extended to all hematologic conditions. She adds that the practice in Hungary varies, some institutions provide Rhesus phenotype and K antigen matched donor RBCs for all hematological patients, while other centers do this kind of matching for all transfused young women. She also reports that some Hungarian centers screen pretransfusion patient samples for unexpected red cell antibodies using enzyme treated reagent red cells and then provide RBC units that are phenotype matched if the antibody screen is positive, even if there is no specific antibody identified. (She comments that to give phenotype-matched RBCs to a patient who has an ENZYME-ONLY antibody is the standard practice in Hungary). She would also like to know if others give Rhesus phenotype matched blood to patients who have an antibody to a non-Rhesus antigen, in addition to avoiding the antigen corresponding to the unexpected antibody.

The following comments have been received.

ADDENDA Dec. 12, 2004

1. The Editor believes that the information in the prior e-Network forum item: Should transfusion of thalassemia patients be managed using phenotype-matched RBC donor units? is germane to this discussion.

ADDENDA Dec 13, 2004

2. A transfusion medicine immunohematologist reports that this subject is summarized in a recent international forum (Vox Sang 2004;87:210-222) (PDF).

ADDENDA Dec. 16, 2004

3. A quality manager at a blood bank in Spain reports that in regards to phenotyping blood donors for Rhesus and Kell, at his blood center (and many other blood centers in Spain), they perform routine phenotyping of donors for Rhesus (they phenotype for D, C, E, c, e) and kell (K) antigens, which are then routinely displayed on the bag label. They do not actually know the efficacy of this policy, but he reports that it is not expensive and is quite useful for hospital transfusion services when an unexpected alloantibody appears. In the case that an unexpected antibody is present, it is their usual practice to select donor RBC units that lack the antigen that corresponds to the unexpected antibody, and not to select donor units that are matched for additional antigens. Only in a case (very uncommon) of a patient having three or more unexpected alloantibodies do they attempt to find "exactly matched" red cells for the patient. Instead of phenotyping the patient, they perform a very comprehensive set of antibody screens for their poly-transfused patients, using several techniques (saline, PEG, enzyme), and at least two red cell panels.

ADDENDA Feb. 6, 2005

4. Editor's Comment: Readers may find the article by Osby, M & Shulman, I. Phenotype Matching of Donor Red Blood Cell Units for Nonalloimmunized Sickle Cell Disease Patients: A Survey of 1182 North American Laboratories. Archives of Pathology and Laboratory Medicine: Vol. 129 No. 2, pp. 190-193, of interest in this discussion.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator