Application of recombinant antigens to blood group diagnostics

Abstract

Conventional red blood cells (RBC)‐based assays use panels of human RBCs carrying a huge number of blood group antigens at the same time and require negative reactions of samples with antigen‐negative cells for indirect determination of antibody specificity. This particularly renders the identification of antibody mixtures and rare RBC antibodies difficult. Many blood group proteins have been recombinantly expressed in sufficient quantity and quality for RBC antibody testing. Recombinant blood group proteins can be used as single antigens in antibody identification assays so that a positive reaction of a serum with the recombinant protein directly indicates the presence and specificity of the target antibody. Recombinant proteins may have wide applications in blood group serology; they can be incorporated in soluble protein reagents or solid‐phase assays such as ELISA, colour‐coded microsphere and protein microarray chip‐based techniques. Because on their capacity for single‐step and direct RBC antibody determination, recombinant protein‐based assays may greatly facilitate and accelerate the identification of common and rare RBC antibodies, resulting in a faster and safer blood supply for immunized patients.