Background: Until now, it was not possible to identify antibodies to red blood cells (RBCs) except with pretyped RBCs. Here, a novel method with particles coated with recombinant Lu(b) protein for detection of anti-Lu(b) is described.
Study design and methods: Prokaryotic recombinant Lu(b) proteins were generated and coupled onto superparamagnetic particles coated with streptavidin. The coated particles were tested in the presence of different serum and plasma samples (13 anti-Lu(b), 6 anti-Lu(a), 20 other antibodies, and 35 serum samples from blood donors) with the particle gel immunoassay (ID-PaGIA).
Results: Lu(b)-coated particles reacted with all 13 samples containing anti-Lu(b), but not with any samples lacking anti-Lu(b). In addition, the anti-Lu(b) titers were higher with Lu(b)-coated particles than with Lu(a-b+) RBCs in almost all cases.
Conclusion: Recombinant blood group proteins may be able to dispense with the need for RBCs for identification of certain RBC alloantibodies.