Overview of the specific immune response

The specific immune response is the normal response of vertebrates when a foreign substance is introduced into the body. This is a desirable protective response which detoxifies, neutralizes, and helps to eliminate such substances. 

However, in some cases, responses to seemingly innocuous substances may cause harm to the host. Such effects are usually termed allergic or hypersensitivity responses. The responses have been classified into four types Type I, Type II, Type III, Type IV. 

Handbook of Biomaterial Properties. Edited by J. Black and G. Hastings. Published in 1998 by Chapman Hall, London, ISBN 0 412 60330 6. 

The main features of the four types of responses are described in the following table  

I IgE B-lymphocytes Histamine, vasoactive amines Itching, rhinitis, vascular collapse 

---