Is extended blood group genotyping a better method to match patient and donor red blood cell donations in blood transfusion dependent patients?

The Australian Red Cross Blood Service is supporting the study to evaluate the benefits of blood group genotyping in chronically transfused patient as a part of a routine transfusion laboratory protocol since this patient group is at greater risk of RBC antigen alloimmunisation. Since these patients form antibodies to red blood cell antigens this can cause laboratory staff to perform laborious and time consuming serological investigations. Performing red blood cell genotyping on these patients will enable better matching of donor units to patients which will potentially reduce the number of transfusions needed by the patient overall and should reduce the number of antibodies they form. To test this theory transfusion data and allo -antibody rates patients who are not receiving closely matched red blood cells units will used. To perform the genotyping, a single research blood sample will be obtained from a newly diagnosed haematology patient who is transfusion naive (or before their next transfusion if they are not transfusion naive but have only had up to 3 transfusions in the last 12 months). This blood sample will be taken at the same time as baseline samples are taken for standard of care requirements and will be 3mL in volume (1 teaspoon). Genomic DNA will be purified and blood group genotyping will be performed on the Australian Red Cross Blood Service HEA bead chip platform. No other blood samples will be used for the genotyping platform. Genotyping results will be provided to the researchers who can advise transfusion staff of which donor unit will be most suitable to transfuse into each patient. Hospital based transfusion laboratory staff will use this information to choose the most suitable unit prior to every transfusion received by that patient during the study period. The most suitable donor unit will be chosen on the closest available phenotype predicted by the genotype results. Donor units are phenotyped to at least 5 of the 39 red blood cell group systems. The decision to choose a unit will depend on how many blood systems each unit has had phenotyped and issued to that particular hospital. In some cases hospital transfusion laboratories can request certain phenotype units to be issued to them for a particular patient. This may be the case if patients are found to require more rare blood types. All other information for this project on the rate of allo-antibody formation rates will be determined from the serum samples collected under routine hospital sample collections before each blood transfusion. The hospital laboratories will perform their own investigations on the serum from the patient to determine if antibodies have formed. This information will be provided to researchers via medical record data and will be used to compare with patients who had no genotyping performed prior to their blood transfusion. The data collection will be performed for each patient for up to 24 months and will vary depending on their individual treatment regimes.