Rapid detection of anti‐Lub with recombinant Lub protein and the particle gel immunoassay

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 Lub protein for detection of anti-Lub is described. STUDY DESIGN AND METHODS: Prokaryotic recombinant Lub 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-Lub, 6 anti-Lua, 20 other antibodies, and 35 serum samples from blood donors) with the particle gel immunoassay (ID-PaGIA). RESULTS: Lub-coated particles reacted with all 13 samples containing anti-Lub, but not with any samples lacking anti-Lub. In addition, the anti-Lub titers were higher with Lub-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.