A colleague in Abu Dhabi, U.A.E., reports that she has read that girls and premenopausal female patients in some European countries are transfused with donor RBC units that are phenotype tested and matched for the CDE and K antigens of the patients, in order to prevent alloimmunization to those antigens and future cases of hemolytic disease of the newborn. The inquiring colleague is considering applying a policy at her hospital blood bank to perform C, D, E, and K antigen phenotype typing of all girls and premenopausal females for whom there is a request to for transfusion. When such a request is received, she would have her laboratory provide donor RBC units matched to the C, D, E, K typing of the patient. She acknowledges that such a strategy might be challenging, given the RBC inventory of her hospital and the central blood bank of Abu Dhabi. She realizes that such an approach is not mandated by the AABB. She wonders if other hospitals are taking a similar approach for the transfusion of girls and premenopausal female patients.

The following comments have been received.

ADDENDA May 8, 2006

1. A Biomedical Scientist who works for the UK National Blood Service reports that current UK policy is that women under 60 years old (i.e. of potential child-bearing age) who are negative for the K-antigen (or whose K type is unknown) and who need an RBC transfusion should receive K negative RBC units. D negative women who need RBC or Platelet transfusion should receive D negative RBC and Platelet products. As the UK donor base is ~90% K negative, the aforementioned policy is not hard to enforce. Most antenatal women that present with anti-K have derived their anti-K from a transfusion, and the aforementioned policy is designed to lower this incidence. Interestingly there is no UK policy to provide matched CDe/CDe (R1R1) RBC for women (i.e. have the potential to make anti-c) who are c-negative. In the responding scientist's opinion, avoiding alloimmunization to c-antigen would be appropriate since anti-c is capable of causing severe HDN, and a c-negative woman is likely to encounter a c-positive partner (in a similar manner to a D-negative woman encountering a D-positive partner). In the UK the frequency of CDe/CDe in the donor population is ~18%.

ADDENDA May 12, 2006

2. A Transfusion Medicine Physician in Australia would like to learn if UK laboratories rely on Kell phenotyping results from the NBS, or if each UK transfusion service laboratory determines the Kell phenotype of its own blood inventory, in order to provide K-negative RBC units to women who are under age 60 who are K-negative or whose Kell type is unknown.

3. In response to the Australian's question, the Biomedical Scientist who works for the UK National Blood Service (see reply #1 above) reports that the NBS has blood processing centers in most major cities in the UK which are linked via a national IT database. This enables them to move blood around the country according to where it is needed most. Their national policy is reportedly to type ALL blood donations for the K antigen (as well as ABO/D C, c, E, e). This is done twice on new donors and once on historic donors for confirmation. The target provision for K typing is set at 98% (this allows for occasional system errors). The resultant blood bag label will state which (non-ABO/Rh) antigens it is negative for (i.e. if it is positive it does not appear). This means the hospitals only have to read the labels of their stock to pick out the K-units. Attached is an example label.

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