title: Implementing mass-scale red cell genotyping at a blood center.
abstract: BACKGROUND
  When problems with compatibility beyond ABO and D arise, currently transfusion services search their inventories and perform time-consuming serologic testing to locate antigen-negative blood. These clinically important blood group antigens can be detected reliably by red cell genotyping, which is a technology whereby DNA-based techniques are used to evaluate gene polymorphisms that determine the expression of blood group antigens. We introduced mass-scale genotyping and measured availability of genotyped blood.
  
  
  METHODS
  All non-Caucasian donors qualified for genotyping along with donors who had a history of repeat donation. Mass-scale red cell genotyping, performed on an electronic interfaced open array platform, was implemented to screen blood donors for 32 single-nucleotide polymorphisms that predicted 42 blood group antigens. Genotype screening results were confirmed by phenotyping, when needed for antigen-negative transfusion, before release of the red blood cell (RBC) unit.
  
  
  RESULTS
  Approximately 22,000 donors were red cell genotyped within 4 months and a total of 43,066 donors in 4 years. There were 463 discordances (0.52% of 89,596 genotypes with a phenotype). Among the 307 resolved discordances, approximate equal numbers represented historical serologic or genotyping discrepancies (n = 151 and n = 156, respectively). In the final year of the study, a mean of 29% of the daily inventory had a genotype.
  
  
  CONCLUSIONS
  Red cell genotyping of blood donors using an electronic interface created a large and stable supply of RBC units with historical genotypes. The database served the needs of antigen-negative blood requests for a large regional blood center and allowed us to abandon screening by serology.
authors.affiliation: Department of Transfusion Medicine, Clinical Center, National Institutes of Health, Bethesda, Maryland.
authors.forename: Willy A
authors.initials: WA
authors.lastname: Flegel
authors.affiliation: Department of Pathology, Medical College of Wisconsin.|Diagnostic Laboratories, BloodCenter of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Jerome L
authors.initials: JL
authors.lastname: Gottschall
authors.affiliation: Diagnostic Laboratories, BloodCenter of Wisconsin, Milwaukee, Wisconsin.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Denomme
mesh_terms: D001782:Blood Donors; D001789:Blood Group Antigens / Q000235:genetics; D001788:Blood Grouping and Crossmatching / Q000379:methods; D004912:Erythrocytes / Q000145:classification / Q000378:metabolism*; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D001789:Blood Group Antigens