Distinct delayed T‐cell response to β ‐methasone and penicillin‐G in the same patient

Background: Multiple drug allergy syndrome is a clinical condition characterized by reactions against more than one different class of, both pharmacologically and structurally, unrelated drugs. Scanty data are available to date about a multiple drug delayed hypersensitivity syndrome. Our aim was to report the case of a delayed reaction to both β ‐methasone ( β ‐MT) and penicillin‐G (pen‐G) occurring in the same patient, and analyse β ‐MT‐ and pen‐G‐specific T‐cell Lines (TCLs) with regard to their specificity, phenotype and cytokine profile. Methods: We generated two drug‐specific TCLs from biopsies at the site of positive intradermal reactions, and analysed their immunophenotype, T‐cell receptor Vβ (TCR‐V β ) domains expression and cytokine profile. Results: We demonstrated the specificity of the T cells isolated from positive intradermal test reactions to pen‐G and β ‐MT through the strict dose‐dependent proliferation in response to drug‐pulsed autologous antigen presenting cells. Fluorescence activated cell sorter (FACS) analysis revealed a predominance of CD4+ cells in the inflammatory cell infiltrate of intradermal test with β ‐MT, while a predominance of CD8+ T cells in the site of delayed reaction to pen‐G was found. The drug specific CD4+ and CD8+ T cells were heterogeneous, with regard to TCR‐V β usage. CD8+ pen‐G‐TCL displayed a preferential T helper 2 (Th2) profile, while a substantially heterogeneous pattern of cytokine production characterized specific β ‐MT TCL. Conclusion: The study describes the coexistence in the same patient of a delayed hypersensitivity to both penicillin G and β ‐MT, driven, respectively, by pen‐G‐specificTh2‐skewed CD8+ and β ‐MT specificTh0 CD4+ T cells. This case further support the existence of a multiple drug allergy syndrome also for delayed hypersensitivity.