Abstract
Abstract 4374
Introduction:
DNA-based tests are increasingly being used to predict blood group phenotypes in patients who have been recently transfused to aid in alloantibody identification, to distinguish an alloantibody from an autoantibody, in patients who have received hematopoietic stem cell transplants, when RBCS are coated with immunoglobulin (+DAT) and to detect weakly expressed antigens when the patient is unlikely to make antibodies to antigen- positive RBC's transfused. The molecular bases associated with most antigens have been determined and PCR-assays available for testing RBC antigens are a powerful adjunct to the conventional hemagglutination, the gold standard technique to type RBCs for the presence or absence of blood group antigens.
Purpose:
This retrospective review of Red Blood cell (RBC) antigen testing data was conducted on all patients typed between January 2010 and December 2011 at MD Anderson Cancer Center. The purpose was to review the concordance between the antibody (ies) identified by serologic testing and the antigen negativity from phenotype predicted from DNA analysis for selecting antigen negative RBCs for transfusion. In addition we also wanted to review whether the extended phenotype red cell units transfused to patients with unidentified alloantibody (ies)/RACT and autoantibodies formed additional red cell alloantibody (ies) after transfusion.
Methods:
The technology of BioArray Solutions (Bioarray Solutions, Immuncor, Norcross, GA, USA) and the Human Erythrocyte Antigen (HEA) v1.2 BeadChip was used to assess the genotype and predicted phenotype of patients. We performed RBC antigen testing on all of our recently transfused patients with alloantibody (ies), patients whose red cell antibody panels showed reaction with all red cells tested (RACT) or unidentified antibodies, patients with positive direct antiglobulin test (DAT) and whose elution studies showing RACT or unidentified antibody (ies) and in patients with autoimmune hemolytic anemia.
Results:
Atotal of 912 BioArray tests were performed on 912 patients [444 (49%) males:468 (51%) females; median age 60 years (range 1–92)]. Antibody screen was positive in 424 (46%) and negative in 488 (54%) patients. A DAT was performed in 126 patients with a positive antibody screen to establish immune from non-immune hemolytic anemia. The results are listed in Tables 1,2 and 3.
Conclusion:
We found 100% concordance between the predicted antigen negativity phenotype and the patient's RBC alloantibody (ies) identified by serologic testing. The RBC antigen typing has allowed us to transfuse patients with unidentified antibodies and RACT with extended phenotype matched red cell units preventing the development of additional red cell alloantibody (ies) as well as allowed us to transfuse antigen-negative units preventing patient/blood donor incompatibility issues.
Disclosures:
No relevant conflicts of interest to declare.
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