T cell reactions in patients showing adverse immune reactions to drugs.

OBJECTIVE AND DESIGN: To better understand how T cells react to small compounds, we investigated the in vitro T cell reactivity to drugs from drug allergic patients. MATERIAL AND SUBJECTS: Peripheral blood mononuclear cells (PBMC) of three drug allergic individuals were stimulated in vitro by different drugs. METHODS: Proliferation was assayed by 3H-thymidine incorporation. Upregulation of activation parameter on T cells was done by immunofluorescence and cytokine release determined via standard ELISA. RESULTS: Drugs can stimulate both CD4 and CD8 T-cell subsets. PenG-stimulated PBMC showed a heterogenous cytokine pattern and clones secreted high amounts of INF gamma. In contrast, sulfamethoxazole and lidocaine-stimulated PBMC secreted high levels of IL-5 and lidocaine-specific clones can be Th1 or Th2-like. CONCLUSION: Drug specific T cells play a pivotal role in drug hypersensitivity reactions, both by regulating the immune response and probably also as specific effector cells with different patterns of cytokine release.