Detection of serum IgE antibodies that react with alcuronium and tubocurarine after life-threatening reactions to muscle-relaxant drugs.

Although anaphylactoid reactions to muscle-relaxant drugs are now well recognised, there has been no general agreement on the mechanism(s) underlying the responses. By covalently coupling alcuronium and tubocurarine to a solid phase carrier and using the resultant complexes in radioimmunoassay experiments with patients' sera and 125I-anti-human IgE, we have found high levels of drug-specific IgE antibodies in the sera of some subjects who reacted to these muscle relaxants. These results provide important supporting evidence that, in some patients at least, life-threatening anaphylactoid reactions to muscle-relaxant drugs are mediated by drug-specific IgE antibodies.