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Detection and quantification of drug‐specific T cells in penicillin allergy
Author(s) -
Rozieres A.,
Hennino A.,
Rodet K.,
Gutowski M.C.,
GuneraSaad N.,
Berard F.,
Cozon G.,
Bienvenu J.,
Nicolas J.F.
Publication year - 2009
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.2008.01674.x
Subject(s) - elispot , allergy , immunology , amoxicillin , penicillin , drug allergy , medicine , immunoglobulin e , drug , antibiotics , microbiology and biotechnology , antibody , t cell , biology , pharmacology , immune system
Drug allergic reactions presenting as maculo‐papular exanthema (MPE) are mediated by drug‐specific T cells. In this study, the frequency of circulating specific T cells was analyzed by interferon‐γ (IFN‐γ) enzyme‐linked immunospot assay in 22 patients with an allergic MPE to amoxicillin (amox). Amox‐specific circulating T cells were detected in 20/22 patients with frequencies ranging from 1 : 8000 to 1 : 30 000 circulating leucocytes. No reactivity was observed in 46 control patients, including 15 patients with immunoglobulin E‐mediated allergy to amoxicillin, 11 patients with a history of drug‐induced MPE but tolerant to amoxicillin and 20 healthy individuals. Furthermore, amox‐specific T cells were still detectable several years after the occurrence of the allergic reaction even after strict drug avoidance. Finally, analysis of drug‐specific T cells in one patient allergic to ticarcillin (a penicillin antibiotic distinct from amox) revealed the presence of IFN‐γ‐producing T cells reactive to ticarcillin and several other betalactam antibiotics, suggesting that the IFN‐γ ELISPOT assay is able to detect T cell cross‐reactivity against chemically related drugs. These findings confirm that drug‐induced MPE is associated with the presence of specific T cells in blood and further suggest that the IFN‐γ ELISPOT is a sensitive assay which could improve the diagnosis of betalactam allergy.