Design of an antigenic determinant of cefaclor: Chemical structure-IgE recognition relationship.

Abstract

Like penicillins, cephalosporins are common antibiotics inducing adverse drug reactions mediated by specific immunologic mechanisms.1 The ‘‘hapten hypothesis’’ states that b-lactams can cause an allergic response only after binding covalently to carrier proteins. In case of cephalosporins, the epitope or antigenic determinant consists of the chemical structure derived after cephalosporin-protein linkage. The lack of knowledge regarding its epitope has hampered the development of standardized in vitro tests to diagnose cephalosporin allergy. Therefore, diagnosis still relies on skin testing and drug provocation tests,2 which, however, are risky, especially for patients with severe reactions. This forces physicians to select alternative b-lactams that, although safe for patients with allergy, may be less effective and show disadvantages related to costs and bacterial resistance.