Mechanism of type I hypersensitivity

Abstract

The increasing prevalence of allergic disorders is currently a serious problem with public health. Understanding of the mechanisms underlying allergies (type I hypersensitivity or immediate reactions) will enable us to improve our treatment with allergic diseases. In this chapter, the features of type I hypersensitivity reactions and the major components involved as well as their potential roles in the induction and regulation of allergic responses are discussed. A half century ago, Gell and Coombs classified the hypersensitivity reactions into four types based on the immunologic mechanisms related to the symptoms in the organism (Gell and Coombs, 1963). Though this classification has many limitations since hypersensitive reactions always showed mixed pathological mechanisms, it is still widely accepted today. Here, we will present our insights on the basic mechanism of type I hypersensitivity reactions.