IN-VITRO DETECTION OF SPECIFIC IGE ANTIBODIES TO ERYTHROMYCIN

Background: In vitro tests for detecting drug-specific IgE would be us eful in identifying patients at risk for immediate hypersensitivity re actions to therapeutic doses of a drug. Objective: We attempted to ver ify that IgE-mediated reactions to erythromycin occur and to identify IgE antibodies specific for erythromycin in serum from a patient who h ad urticaria immediately after administration of the drug. Methods: Sk in prick testing was performed on the patient and five control subject s. Serum from the patient, pooled sera from nonatopic subjects allergi c to common aeroallergens, and cord blood controls were analyzed for e rythromycin-specific IgE by radioimmunoassay. Sepharose (Pharmacia, Up psala, Sweden) was used as solid phase covalently linked to erythromyc in Results: We were able to detect erythromycin-specific IgE antibodie s in serum from the patient who had an allergic reaction to this antib iotic, but specific IgE could not be detected in control sera. Conclus ion: immunologic IgE-mediated reactions to erythromycin do occur, and in vitro diagnosis of such reactions can be made by using Sepharose as a solid phase covalently linked to this drug.