High-level, stable expression of blood group antigens in a heterologous system

The detection and identification of blood group antibodies in patients is c rucial for successful allogeneic blood transfusions. Current methods are hi ghly subjective and rely on red blood cells (RBCs), which simultaneously ex press many blood group antigens, have a short shelf-life, and carry potenti al biohazard risks, To overcome these problems, we have used the approach o f expressing individual blood group antigen-bearing proteins in a heterolog ous system, We report here the high-level surface expression of type I (Kno ps), type II(Kell), and type III/multi-pass (Duffy) membrane proteins that carry blood group antigens in mouse erythroleukaemic (MEL) cells using a ve ctor containing the beta-globin locus control region. importantly, the anti gens expressed were detected specifically by a panel of patients' sera cont aining alloantibodies at sensitivities that are comparable to antigen-posit ive RBCs. Furthermore, in contrast to other mammalian expression systems, a ntigen expression was stable following freezing and thawing of the cell lin es. Thus, this system has the potential both to replace the current use of RBCs by providing a one step method to detect and identify blood group anti bodies and to allow the automation of antibody identification for the clini cal laboratory, Am. J. Hematol. 63:114-124, 2000. (C) 2000 Wiley-Liss, Inc.