Ordering Phenotyped Blood
All requests for phenotyped blood should be placed using OBOS
For advice on complex phenotyped blood requirements telephone your Red Cell Immunohaematology laboratory where possible 48 hours in advance. Out of hours, contact the Hospital Services department.
When no blood sample has been referred for antibody identification, phenotyped units will be supplied as requested. Ideally, a sample should be referred for confirmation of antibody specificity and to exclude the presence of additional alloantibodies. An antibody card will then be issued.
Policy on phenotyped blood & extended phenotyping/genotyping
It is recommended that transfusion dependant patients (i.e thalassemia syndromes, severe aplastic anaemia, sickle cell disease and other congenital or acquired anaemias) have an extended phenotype performed prior to any transfusions and that Rh and K compatible blood is used. Patients who have received recent multiple transfusions may be genotyped for the same antigens by RCI.
Matching of red cells based on patients Rh & K phenotype:
|Patient's Type||Select for Crossmatching|
|RO||RO (usually available) or rr|
|K negative||K negative|
Policy on phenotyped blood for patients with antibodies
The policy is to supply red cells, negative for the relevant red cell antigen(s) for patients with clinically significant red cell alloantibodies present or in whom they were detected in the past, for example, anti-Jka.
The thermal range is the best parameter to determine the clinical significance of an alloantibody and, in general antibodies not reacting at 37°C may be ignored for red cell transfusions and antigen-negative blood is not provided for patients with cold reacting antibodies. For details, see the British Society for Haematology guidelines for pre-transfusion compatibility procedures in blood transfusion laboratories.
It is recommended that K negative units are selected for all female patients of <60 years of age (unless they have anti-k) in order to reduce the incidence of anti-K in pregnant women.
Provision of phenotyped blood
Donations are tested for Rh phenotype and K, thus most Rh phenotypes are readily available and supplied. Other phenotypes, such as Fya and Jka negative are generally in stock. The confirmed antigen status is printed on the pack label therefore there is no need for hospitals to retype units.
If suitable units are not available from local stocks, NHSBT centre staff will obtain them from other centres. In rare cases, blood can be made available from the national frozen blood bank in Liverpool or suitable donors may be invited to donate.
Frozen blood bank
Units from the frozen blood bank at NHSBT Liverpool are processed in a closed system and need to be transfused within 72 hours after thawing.
Requests for recovery of frozen units should be made well in advance and five working days before the planned transfusion, if possible. NHSBT centre staff will liaise with the appropriate organisations outside the UK on your behalf, if suitable blood units are not available at NHSBT Liverpool.
Autologous frozen units
Autologous blood may be collected and frozen, if a patient has a combination of red cell alloantibodies or antibodies against a high frequency (public) antigen, which makes it almost impossible to find a suitable donor. This must first be discussed with consultant medical staff at the NHSBT centre.