IgG and IgE Antibodies in Subjects Allergic to Penicillins Recognize Different Parts of the Penicillin Molecule

Abstract

Background: IgE and IgG antibodies to penicillins can have different specificities. However, this response, including the recognition of the different parts of penicillin, has never been studied in the same subject. Objective: Study of the specificity of IgE and IgG antibodies and the relevant parts of the penicillin molecule that contribute to the hapten binding site in sera from human. Methods: Specific IgE antibodies were determined by RAST and specific IgG antibodies by ELISA. The recognition of the different molecules was studied by inhibition studies. Results: Seven sera with IgG and IgE antibodies to amoxicillin and benzyl penicillin were analyzed. IgE antibodies recognized mainly two different epitopes: in one, the side chain was a relevant part of the epitope, in the other, it was the nuclear portion. IgG antibodies recognized the nuclear portion in all instances. In the same subject, antibodies of different isotype and specificity were found. Conclusions: Subjects who develop simultaneously IgE and IgG antibodies to penicillins show different specificities. This proves that different populations of antibodies recognize different epitopes.

Induction of accelerated reactions to amoxicillin by T-cell effector mechanisms

“…12 Although we present a limited number of cases, it is of note that the delayed skin test intradermal response was negative. Concerning the T-cell response, these result are not surprising, and the low sensitivity of skin testing in T-cellemediated reactions has been reported.…”

Rapid desensitization for non-immediate reactions in patients with cystic fibrosis

“…These have been detected in certain individuals [15,16] and it has been demonstrated that anti-penicillin antibody titers rise rapidly during desensitization and then decline slowly with time [15]. The speed of the response in desensitized patients would be in keeping with a secondary antibody response.…”

Idiosyncratic Adverse Drug Reactions: Current Concepts

“…They influence the T-cell response by enhancing antigen capture and delivery by modulating processing pathways, thus suppressing the generation of dominant antigenic determinants and by preventing processing (Watts and Lanzavecchia, 1993). We and others have used drug-protein conjugates to detect anti-drug antibodies in certain tolerant and allergic patients (de Haan et al, 1986;Christie et al, 1988;Daftarian et al, 1995;Torres et al, 1997). However, the dynamics of the drug antigen-specific humoral response and the kinetics of antibody production have not been defined.…”

“…It is possible that this pathway of drug-specific T-cell activation is an in vitro artifact mimicking the action of processed haptenmodified peptides. Importantly, several groups have used b-lactam albumin conjugates to detect antidrug antibodies in tolerant and allergic patients (de Haan et al, 1986;Christie et al, 1988;Torres et al, 1997). Thus, hapten theory is thought to accurately describe the drug-specific activation of B cells that recognize protein antigens directly through their B cell receptor.…”