K, Fy(a), and Jk(a) phenotyping of donor RBCs on microplates.

Abstract

In many cases, the search for compatible blood for patients with clinically significant RBC alloantibodies is difficult and time-consuming. To date, it has been considered necessary only to phenotype the blood donors for ABO group and D. There has been long experience with automated routine analysis (ABO, C, c, D, E, and e typing and RBC antibody screening), using robotic dispensers and computerized interpretation of microplate results. The purpose of this study was to explore the possibilities of also phenotyping for K, Fy(a), and Jk(a), as antibodies directed against these antigens (together with Rh antigens) are the most common clinically significant alloantibodies in the Swedish population. One thousand thirty-one EDTA samples from blood donors were phenotyped for K, Fy(a), and Jk(a) by use of an IAT with PEG on microplates. The findings were compared to those using conventional IAT in tube's and the microcolumn gel test (DiaMed-ID, DiaMed). All typing results with the microplate method were correct. All reactions for K and Fy(a) typing could be interpreted by the computer. The results for Jk(a) were indeterminate in 1.4 percent (14/1031) of the samples. The PEG-IAT microplate method gave reliable results that were suitable for routine phenotyping, thus making available a stock of phenotyped blood at reasonable cost, ready for delivery when required.