Figure 13.1

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   Autoimmune diseases classified by the mechanism of tissue damage

Autoimmune diseases can be grouped in the same way as hypersensitivity reactions, according to the type of immune response and the mechanism by which it damages tissues. The immunopathological mechanisms are as illustrated for the hypersensitivity reactions in Fig. 12.2, with the exception of the type I IgE-mediated responses, which are not a known cause of autoimmune disease. Some additional autoimmune diseases in which the antigen is a cell-surface receptor, and the pathology is due to altered signaling, are listed later in Fig. 13.11. Several immunopathogenic mechanisms operate in parallel to cause many autoimmune diseases. This is illustrated in the case of rheumatoid arthritis, which appears in more than one category of immunopathological mechanism.