According to a blood banker in Ontario, Canada, a pediatrician has asked that the transfusion of thalassemia patients be managed using phenotype-matched RBC donor units. The inquiring blood banker's hospital transfusion service has not provided phenotype-matched RBC donor units in the past. However, another hospital in the same general area provides K antigen negative blood upon request for the transfusion of thalassemia patients. Apparently, the use of K antigen negative donor RBC units for the transfusion of thalassemia patients has been a practice at the other hospital for some time; the apparent reason for this policy is that the K antigen is next in antigenicity to the D antigen. The Canadian blood banker believes that the Canadian Red Cross and now the Canadian Blood Services have never questioned specific requests for K antigen negative RBC units, probably because the units are easy to find. However, the inquiring blood banker has just had a call about her institution's phenotype matching policy from another hospital, so she would really like to know what accepted practice is. The Canadian blood banker wants to know what other hospitals are doing with regards to phenotype matching donor RBC units for thalassemia patients.

The following replies were submitted in response to the above:

1. Editor's note: The e-network forum might be interested to read a related earlier discussion which deals mainly with the selection of donor RBC units for the transfusion of sickle cell disease patients, but which also touches on the selection of donor RBC units for the transfusion of thalassemia patients.

2. A blood banker in Ohio replies that the policy at her facility covering this practice reads as follows: "Sickle cell anemia patients who receive multiple red blood cell (RBC) transfusions are at increased risk of developing RBC antibodies. This is a result of the difference in expression of RBC antigens within ethnic groups. Most volunteer blood donors are Caucasian and express some red cell antigens more frequently than do African-Americans. Experience at many centers and in several studies have demonstrated that by providing RBC's that are partially matched for several red cell antigens there is a reduced incidence of alloimmunization to other dissimilar antigens. Based on this information, the Transfusion Services are changing the policy regarding provision of RBC's for patients with all forms of sickle cell anemia ( SS, SC, S-beta thalassemia) and African-Americans with alpha or beta thalassemia syndromes receiving transfusion therapy. Upon notification to the Transfusion Service by the patient's attending physician, each of these patients will be phenotyped for the RBC antigens: D, C, c, E, e, Kell. Red cell transfusions will be antigen-negative for the red cell antigens the patient is lacking."

ADDENDUM April 15, 2002

3. An Australian blood banker reports that his facility currently manages the transfusion of 25 adult thalassaemia patients. In regard to provision of Kell-negative blood units, this is only applied to female patients under 45 years of age. Additionally they do not provide phenotyped units for patients without antibodies; it is only when specific, clinically significant antibodies are involved that phenotyped matched units are selected. Of the 25 chronically transfused thalassemia patients, only 5 have antibodies of significance.

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