The potential of blood group genotyping for transfusion medicine practice.

Molecular diagnostics is the fastest growing area of clinical laboratory medicine. The ability to rapidly amplify genes of bacterial, viral, or human origin, and the development of DNA array platforms, are driving a technology revolution in the clinical laboratory. A DNA-based testing approach is particularly applicable to blood bank and transfusion medicine for rapid, cost-effective antigen typing. Experience with DNA-based methods during the past decade has shown that these assays are reproducible and highly correlated with the RBC phenotype. The recent availability of automated, high-throughput, DNA-array platforms now moves testing from the reference laboratory setting into hospital and donor testing centers. This approach has the potential to revolutionize the process of locating antigen-negative donor units by testing for all clinically significant blood group antigens in a single assay. When partnered with the same extended typing of the patient, electronic selection of units antigen-matched at multiple blood group loci is then possible. This paper discusses the potential of this approach to improve transfusion therapy by reducing or eliminating alloantibody production in specific patient populations. These include patients facing long-term transfusion therapy and at high risk for sensitization; patients with warm autoantibodies when compatibility cannot be demonstrated by standard methods; and women for whom the production of atypical antibodies carries a risk for hemolytic disease of the fetus and newborn, or at the very least, monitoring for an at-risk pregnancy.