Máire Geoghegan-Quinn
Ceist:139 Mrs. Geoghegan-Quinn asked the Minister for Health whether testing is done as a matter of routine by the Blood Transfusion Service Board for Kell antigen; and if he will make a statement on the matter. [21522/96]
Written Answers. - Kell Antigens.
Limerick East): The Blood Transfusion Service Board has informed me that the various blood group systems together contain over 400 characterised antigens, the vast majority of which are so weak that they rarely cause clinical problems. Only two, the ABO and rhesus D, RHD, systems, require routine prospective matching prior to blood transfusion. All donated blood is routinely typed for ABO and rhesus D antigens. The remaining blood group differences present problems for only a small number of patients for whom a previous sensitising episode, usually from pregnancy or earlier transfusion, has stimulated the formation of antibodies which necessitates the selection of more accurately matched blood for transfusion.
The Kell antigen of the K blood group has the potential to provoke an antibody response. Research in relation to donors shows that about 91 per cent of the general population are Kell negative and the frequency of Kell positive type in the population is therefore 9 per cent. Only about 5 per cent of Kell negative patients transfused with a unit of Kell positive blood will produce anti-Kell. Accordingly, the chance associated with receiving a Kell positive unit and becoming immunised is quite low. However, given the large scale of blood transfusion the anti-Kell is a comparatively common antibody detected among transfusion recipients. Therefore, before any patient receives a transfusion a small sample of blood is routinely tested for antibodies and cross matched against the prospective donation. The BTSB routinely screens for the provision of Kell negative or any antigen negative blood upon request from hospitals. If a Kell antibody is detected, the BTSB will provide Kell negative blood which is more accurately compatible im meeting individual patient requirements.
Anti-Kell can also cause haemolytic disease in a Kell positive newborn if the mother is K negative and is immunised. Routine screening for antibodies, including Kell antibodies, is available within the health care sector for all women during pregnancy as part of the standard care and management protocols during pregnancy. If a Kell antibody is detected the pregnant woman is referred for specialist management and where necessary appropriate treatment.
The medical consultants at the BTSB and the board's scientific committee are at present assessing the technical requirements necessary to make available Kell negative blood transfusion to females of child bearing potential, who require blood transfusion.