Diclofenac hypersensitivity: antibody responses to the parent drug and relevant metabolites

• Published in: PloS one 2010-10, Vol.5 (10), p.e13707
• Main Authors: Harrer, Andrea, Lang, Roland, Grims, Robert, Braitsch, Michaela, Hawranek, Thomas, Aberer, Werner, Vogel, Lothar, Schmid, Walther, Ferreira, Fatima, Himly, Martin
• Format: Article
• Language: English
• Subjects: Allergic reactions; Allergy; Analysis; Anaphylaxis; Anemia; Animals; Anti-Inflammatory Agents, Non-Steroidal - adverse effects; Antibodies; Antibodies - immunology; Antigen-antibody reactions; Basophils - immunology; Biochemistry; Biological activity; Biological products; Blood; Carriers; Case studies; Conjugates; Crosslinking; Cytochrome; Dermatology; Diclofenac; Diclofenac - adverse effects; Drug dosages; Drug Hypersensitivity - immunology; Effector cells; Enzyme-Linked Immunosorbent Assay; Ethics; Experiments; Female; Haptens; Humans; Hypersensitivity; Immunization; Immunoglobulin E; Immunoglobulin E - immunology; Immunoglobulin G; Immunoglobulins; Immunology; Immunology/Allergy and Hypersensitivity; Mass spectrometry; Metabolism; Metabolites; Mice; Mice, Inbred BALB C; Molecular biology; Nonsteroidal anti-inflammatory agents; Nonsteroidal anti-inflammatory drugs; Organic chemistry; Patients; Pharmacology/Adverse Reactions; Proteins; Scientific imaging
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0013707

Hypersensitivity reactions against nonsteroidal antiinflammatory drugs (NSAIDs) like diclofenac (DF) can manifest as Type I-like allergic reactions including systemic anaphylaxis. However, except for isolated case studies experimental evidence for an IgE-mediated pathomechanism of DF hypersensitivity is lacking. In this study we aimed to investigate the possible involvement of drug- and/or metabolite-specific antibodies in selective DF hypersensitivity. DF, an organochemically synthesized linkage variant, and five major Phase I metabolites were covalently coupled to carrier proteins. Drug conjugates were analyzed for coupling degree and capacity to crosslink receptor-bound IgE antibodies from drug-sensitized mice. With these conjugates, the presence of hapten-specific IgE antibodies was investigated in patients' samples by ELISA, mediator release assay, and basophil activation test. Production of sulfidoleukotrienes by drug conjugates was determined in PBMCs from DF-hypersensitive patients. All conjugates were shown to carry more than two haptens per carrier molecule. Immunization of mice with drug conjugates induced drug-specific IgE antibodies capable of triggering mediator release. Therefore, the conjugates are suitable tools for detection of drug-specific antibodies and for determination of their anaphylactic activity. Fifty-nine patients were enrolled and categorized as hypersensitive either selectively to DF or to multiple NSAIDs. In none of the patients' samples evidence for drug/metabolite-specific IgE in serum or bound to allergic effector cells was found. In contrast, a small group of patients (8/59, 14%) displayed drug/metabolite-specific IgG. We found no evidence for an IgE-mediated effector mechanism based on haptenation of protein carriers in DF-hypersensitive patients. Furthermore, a potential involvement of the most relevant metabolites in DF hypersensitivity reactions could be excluded.