Roles of cytotoxic T lymphocytes in the pathogenesis of drug eruption

Abstract

Drug eruption is a common delayed hypersensitivity reaction. Its pathogenesis can be usually explained by three theories, including haptens, pro-haptens and pharmacological interaction with immune receptors (the p-i concept). Drug-specific cytotoxic T lymphocytes (CTLs) play an important role in the pathological process of drug eruption. In classic theories, CTLs are commonly recognized as CD8 + T cells, but new evidences indicate that other immune cells with different phenotypes, such as CD4 + T cells, also have cytotoxicity. In the development of drug eruption, these immune cells are specifically activated to contact with target cells followed by the release of cytotoxins. Target cells can provide a favoring environment for the metabolism of drugs and occurrence of inflammation and apoptosis, and assist CTLs to function. In addition, the danger signal hypothesis suggests that danger signals play an important role in immune activation, which enriches our knowledge on the pathogenesis of drug eruption. Key words: Drug eruptions; T-lymphocytes, cytotoxic; Risk factors; CD8-positive T-lymphocytes; CD4-positive T-lymphocytes