Modes of presentation of chemical neoantigens to the immune system.

The immune system can interact with small molecular compounds like drugs. Drugs are not only immunogenic because of their chemical reactivity, but also because they may bind in a labile way to MHC-molecules and fit into available T-cell receptors. This seems to be sufficient to stimulate T-cells. Such structural features of a drug have to be considered in the evaluation of drug hypersensitivity reactions and should be taken into account in predictive drug allergy testing.