Analysis of Erythrocyte Membrane Alloantigens

Red blood cell (RBC) transfusion is a critical medical intervention for managing various diseases marked by anemia. However, this treatment carries the risk of alloimmunization, which can result in hemolysis following an incompatible RBC transfusion. Exposure to RBC alloantigens on fetal RBCs can likewise induce a maternal alloimmune response in the setting of pregnancy. Antibody-mediated immunosuppression (AMIS) is currently the only known method to actively prevent alloimmunization following allogeneic RBC exposure. While the mechanism of AMIS remained enigmatic for many years, recent studies suggest that passively administered antibodies may, in part, prevent de novo alloimmunization by inducing the removal of the target antigen from the RBC surface. Although antibody-mediated antigen removal can be detected indirectly by flow cytometry, western blot analysis of the target antigen provides a more definitive assessment of antigen removal following antibody engagement. We will describe the methods used to isolate RBC membrane proteins and analyze the levels of antigen using western blot techniques by employing the Hen egg lysozyme, Ovalbumin, and Duffy (HOD) model system as an example.