title: β-Lactam antibiotics form distinct haptenic structures on albumin and activate drug-specific T-lymphocyte responses in multiallergic patients with cystic fibrosis.
abstract: β-Lactam antibiotics provide the cornerstone of treatment for respiratory exacerbations in patients with cystic fibrosis. Unfortunately, approximately 20% of patients develop multiple nonimmediate allergic reactions that restrict therapeutic options. The purpose of this study was to explore the chemical and immunological basis of multiple β-lactam allergy through the analysis of human serum albumin (HSA) covalent binding profiles and T-cell responses against 3 commonly prescribed drugs; piperacillin, meropenem, and aztreonam. The chemical structures of the drug haptens were defined by mass spectrometry. Peripheral blood mononuclear cells (PBMC) were isolated from 4 patients with multiple allergic reactions and cultured with piperacillin, meropenem, and aztreonam. PBMC responses were characterized using the lymphocyte transformation test and IFN-γ /IL-13 ELIspot. T-cell clones were generated from drug-stimulated T-cell lines and characterized in terms of phenotype, function, and cross-reactivity. Piperacillin, meropenem, and aztreonam formed complex and structurally distinct haptenic structures with lysine residues on HSA. Each drug modified Lys190 and at least 6 additional lysine residues in a time- and concentration-dependent manner. PBMC proliferative responses and cytokine release were detected with cells from the allergic patients, but not tolerant controls, following exposure to the drugs. 122 CD4+, CD8+, or CD4+CD8+ T-cell clones isolated from the allergic patients were found to proliferate and release cytokines following stimulation with piperacillin, meropenem, or aztreonam. Cross-reactivity with the different drugs was not observed. In conclusion, our data show that piperacillin-, meropenem-, and aztreonam-specific T-cell responses are readily detectable in allergic patients with cystic fibrosis, which indicates that multiple β-lactam allergies are instigated through priming of naïve T-cells against the different drug antigens. Characterization of complex haptenic structures on distinct HSA lysine residues provides a chemical basis for the drug-specific T-cell response.
authors.affiliation: MRC Centre for Drug Safety Science, Department of Pharmacology, The University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, England.
authors.forename: Rosalind E
authors.initials: RE
authors.lastname: Jenkins
authors.forename: Fiazia S
authors.initials: FS
authors.lastname: Yaseen
authors.forename: Manal M
authors.initials: MM
authors.lastname: Monshi
authors.forename: Paul
authors.initials: P
authors.lastname: Whitaker
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Meng
authors.forename: John
authors.initials: J
authors.lastname: Farrell
authors.forename: Jane
authors.initials: J
authors.lastname: Hamlett
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Sanderson
authors.forename: Sabah
authors.initials: S
authors.lastname: El-Ghaiesh
authors.forename: Daniel
authors.initials: D
authors.lastname: Peckham
authors.forename: Munir
authors.initials: M
authors.lastname: Pirmohamed
authors.forename: B Kevin
authors.initials: BK
authors.lastname: Park
authors.forename: Dean J
authors.initials: DJ
authors.lastname: Naisbitt
mesh_terms: D001398:Aztreonam / Q000737:chemistry / Q000276:immunology; D003550:Cystic Fibrosis / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D004342:Drug Hypersensitivity / Q000150:complications / Q000276:immunology*; D006241:Haptens / Q000737:chemistry* / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000276:immunology*; D000077731:Meropenem; D015394:Molecular Structure; D010878:Piperacillin / Q000737:chemistry / Q000276:immunology; D012709:Serum Albumin / Q000737:chemistry*; D013601:T-Lymphocytes / Q000276:immunology*; D013845:Thienamycins / Q000737:chemistry / Q000276:immunology; D065093:beta-Lactamase Inhibitors / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use; D047090:beta-Lactams / Q000737:chemistry / Q000276:immunology* / Q000627:therapeutic use
chemical_list: D006241:Haptens; D012709:Serum Albumin; D013845:Thienamycins; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; D000077731:Meropenem; D001398:Aztreonam; D010878:Piperacillin