A model for integrating molecular-based testing in transfusion services.

BACKGROUND: Molecular-based laboratory tests can predict blood group antigens and supplement serological methods, adding a unique technology to assist in resolving discrepant or incomplete blood group typing or antibody identification. Hospital transfusion services have options for integrating molecular-based methods in their routine operations. We describe here the model of a hospital-reference laboratory partnership. MATERIALS AND METHODS: Blood samples for compatibility testing were obtained from patients in a 609-bed hospital serving an urban multiethnic and multiracial population. When results of blood group phenotyping by serological methods were inconclusive, samples were referred for molecular-based testing. The reference laboratory used several methods for genotyping, including polymerase chain reaction followed by restriction enzyme-linked polymorphism analysis, sequence-specific primer polymerase chain reaction and array-based approaches. Human erythrocyte antigen, RHCE and RHD single nucleotide polymorphism arrays were integrated into the laboratory as they became commercially available. RESULTS: The hospital-reference laboratory model made it possible to integrate blood group genotyping promptly by current technology without the expense of new laboratory equipment or adding personnel with technical expertise. We describe ten cases that illustrate the categories of serological problems that were resolved by molecular methods. DISCUSSION: In-hospital molecular testing for transfusion services has logistical advantages, but is financially impractical for most hospitals. Our model demonstrates the advantages of a hospital-reference laboratory partnership. In conclusion, hospital transfusion services can integrate molecular-based testing in their routine services without delay by establishing a partnership with a molecular blood group reference laboratory. The hospital reference-laboratory model promotes genomic medicine without the expense of new equipment and skilled personnel, while supporting the economy of centralised large-scale laboratory operations.

New laboratory procedures and Rh blood type changes in a pregnant woman.

BACKGROUND: A woman's candidacy for Rh immune globulin depends on whether her blood type is Rh-positive (D antigen-positive) or Rh-negative (D antigen-negative). New molecular blood-typing methods have identified variant D antigens, which may be reported as Rh-positive or Rh-negative depending on the laboratory method. We describe a case illustrating the effect of the new laboratory methods on a woman's candidacy for Rh immune globulin and present recommendations for interpreting the new test results. CASE: A 40-year-old woman presented for management of her third pregnancy. During her first pregnancy, she was typed as Rh-positive ("D") and did not receive Rh immune globulin. During her second pregnancy, she was typed as Rh-negative, in accordance with revised Rh-typing procedures. Anti-D antibody was detected. During her third pregnancy, she was genotyped as a partial D antigen, which was reported as Rh-negative. CONCLUSION: Revisions in laboratory procedures for Rh typing may present as a change in the Rh blood type of pregnant women-and as a change in their eligibility for Rh immune globulin.

Radiofrequency identification technology can standardize and document blood collections and transfusions.

BACKGROUND: We evaluated the potential for radiofrequency (RF) transponder microchips to standardize and document key steps in the blood collection and transfusion process. STUDY DESIGN AND METHODS: Using the blood center's standard operating procedures for blood collections, we programmed a laptop computer and 10 multiwrite 256-byte RF microchips to prompt operators to enter data for key steps in blood collection. Before collections, RF microchips were attached to blood collection sets at the blood center. In parallel with actual collections, we added data to the microchips with the computer and a hand-held scanner-programmer. After labeling, we shipped the RF microchip-tagged blood units to the hospital where unit-related data (whole blood number, ABO and Rh, expiration date, special laboratory test results) were uploaded from the RF microchip to the transfusion service's information system. The microchip was subsequently used as a cross-match label for blood unit-recipient matching. RESULTS: Data were successfully uploaded to the RF microchip at key steps during blood collections. Software programs in the laptop computer and hand-held scanner-programmer successfully prompted operators to enter key data. At any stage in a blood collection, authorized operators were able to review electronic records of prior steps using the laptop computer or by scanning the microchip attached to the blood bag. Unit-related data were successfully transferred to the hospital transfusion service through the RF microchip. These data were successfully incorporated in the RF microchip cross-match label, which was used to confirm recipient-blood unit matching at the bedside. CONCLUSION: RF microchips can collect key data during blood collections, facilitate information transfer from the blood center to the hospital, and confirm recipient-blood unit matching at the bedside before transfusions.