Erythrocyte-magnetized technology: an original and innovative method for blood group serology

BACKGROUND: Erythrocyte-magnetized technology (EMT) is a new fully automated method for ABO-RH-K phenotyping and antibody detection. The magnetization of red cells avoids centrifugation and washing phases. This report describes the results of an evaluation of this new technology on its specific automated system. STUDY DESIGN AND METHODS: ABO-RH-K phenotyping was compared between EMT and a semiautomated routine method (liquid microplate for ABO-D and microcolumn system for RH-K) on 311 patients' samples. The overall performance of the new method was further assessed in daily routine on a total of 11,022 samples during 3 months in two different laboratories. Antibody detection was evaluated on 624 consecutive patients' samples and on 118 frozen samples containing specific antibodies in comparison with commercial microcolumn systems. RESULTS: Eight of 311 ABO-RH-K tests (2.6%) were not interpreted by EMT. Seven of them were weak antigen or reverse grouping reactions showing a negative result with the routine method. On a 3-month follow-up, 216 of 11,022 tests (1.96%) were not interpreted by the system, 75 percent of them being due to weak or mixed-field reactions. EMT was better in detecting ABO-D mixed-field reaction than routine microplate method. Detection of clinically significant antibodies was similar between EMT and microcolumn. In contrast, EMT detected a markedly lower rate of presumed nonsignificant antibodies. The system presents an overall high reliability. CONCLUSION: EMT is tailored to meet the needs of the transfusion service and represents an important advance in the field of immunohematology.