Gell and Coombs classification


Gell and Coombs classification

 [jel; ko̳mz] a classification of immune mechanisms of tissue injury, comprising four types of hypersensitivity reactions: type I,hypersensitivity" >immediate hypersensitivity reactions, mediated by interaction of IgE antibody and antigen and release of histamine and other mediators; type II, antibody-mediated hypersensitivity reactions, due to antibody-antigen interactions on cell surfaces; type III, immune complex–mediated hypersensitivity reactions, local or general responses" >inflammatory responses due to formation of circulating immune complexes and their deposition in tissues; and type IV cell-mediated hypersensitivity reactions, hypersensitivity" >delayed hypersensitivity reactions initiated by sensitized T lymphocytes either by release of lymphokines or by T-cell–mediated cytotoxicity.

Gell and Coombs Clas·si·fi·ca·tion

(gel kūmz), a classification system that differentiates the four types of hypersensitivity reactions: Type I: anaphylactic reactions, Type II: cytotoxic reactions, Type III: immune complex reactions, and Type IV: cell-mediated/delayed hypersensitivity reactions.