Characterization of an antigen in acute anaphylactic dialysis reactions: ethylene oxide-altered human serum albumin.

Anaphylactic reactions to dialysis have been associated with antibody to human serum albumin (HSA) that has been reacted with ethylene oxide (ETO). ETO, an agent used to sterilize dialyzers, is a potent alkylator of proteins. We have studied the antigenic characteristics of ETO-HSA. By use of immunoelectrophoresis we have demonstrated differences in electrophoretic mobility between HSA and ETO-HSA. By gel chromatography we have observed an apparent increase in the molecular weight of ETO-HSA as compared to HSA. Antigenic activity of ETO-HSA as determined by the technique of Lidd and Farr is found in all molecular weight fractions. Cutaneous reactivity to ETO-HSA can be transferred to subhuman primates. That reactivity is lost if the sera are heated to 56 degrees C for 4 hours. Antibody activity to ETO-HSA cannot be inhibited by ETO-glycine or HSA but can partially be inhibited by ETO-polylysine or ETO-ovalbumin. This suggests that antibody is directed against a new antigenic determinant on the ETO-protein moiety, probably an ETO-amino acid determinant like lysine.