Delayed drug hypersensitivity reactions - new concepts.

摘要: Summary Immune reactions to small molecular compounds such as drugs can cause a variety of diseases mainly involving skin, but also liver, kidney, lungs and other organs. In addition the well-known immediate, IgE-mediated drugs, many drug-induced hypersensitivity appear delayed. Recent data have shown that in these delayed drug-specific CD4+ CD8+ T cells recognize through their cell receptors (TCR) an MHC-dependent way. Immunohistochemical functional studies drug-reactive patients with distinct forms exanthems revealed functions lead different clinical phenotypes. Taken together, allow (type IV) be further subclassified into reactions, which by releasing certain cytokines chemokines preferentially activate recruit monocytes IVa), eosinophils IVb), or neutrophils IVd). Moreover, cytotoxic either IVc) seem participate all type IV reactions. Drugs are not only immunogenic because chemical reactivity, they may bind labile way available TCRs possibly MHC-molecules. This seems sufficient stimulate certain, probably preactivated cells. The drug first fitting TCR, already exerts some activation. For full activation, additional interaction TCR MHC molecules is needed. binding receptor structures reminiscent pharmacological between its (immune) was thus termed p–i concept. hypersensitivity, response occurs within hours even upon exposure drug. reaction might due classical, primary response, peptide-specific happen stimulated new concept has major implications for understanding immunological features model explain frequent skin symptoms proposed.