IgE antibodies against penicillin as determined by Phadebas RAST


Dr A. Basomba, Ciudad Sanitaria de la Seguridad Social LA FE, Departamento de Medecina Interna, Servicio de Alergia, Valencia, Spain.


Serum samples from eighty-one patients with suspected penicillin allergy were investigated with Phadebas RAST using the penicillin derivatives Benzylpenicilloyl-human serum albumin (PBO-HSA) and Phenoxymethylpenicilloyl-human serum albumin (PMPO-HSA) and the results were compared with skin test results and clinical data.

Of the sixty-one patients who had anaphylactic shock and/or urticaria as a possible consequence of penicillin administration, reagins against PBO-HSA and PMPO-HSA could be detected in thirty-four cases (56%). Five per cent of these patients, with positive RAST results, showed negative skin tests; in the other 95% both RAST and skin tests were positive. All, except eight, of the RAST-negative patients had had their adverse reactions at least 2 years prior to the blood sampling and in some of these cases skin tests were also negative. RAST and provocation test results agreed in 80% of the cases where exposition was performed. It is concluded that the RAST technique is a valuable diagnostic tool for the detection of immediate type hypersensitivity to penicillin.