Type III Hypersensitivity-Related Disorders in Animals

Kohli N and Chauhan RS (2020). Type III Hypersensitivity-Related Disorders in Animals. Journal of Immunology Immunopathology, 22(1): 48-55.

Immune complex diseases encompass a variety of disease states in man and animals due to the deposition of circulating antigen-antibody complex in body tissues, leads to the activation of complement cascade pathway that triggers the generation of chemical mediators of inflammation thereby the development of pathological alterations. Normally the immune complexes are formed in the body are taken care by the various phagocytic cells, which are capable of removing foreign antigen from the system. However, presence of persistent infection or repeated exposure to an antigen or in case of self-antigen, the formation of antigen-antibody complexes get enhanced and which may escape from the phagocytic cells and get deposited in tissues that provoke Type III hypersensitivity or immune complex-mediated hypersensitivity reaction. There are two types: systematic/generalised immune complex-mediated reaction, for example, serum sickness and Localised immune complex-mediated reaction, for example, Arthus reaction. There are certain diseases where circulating antigen-antibody complexes are thought to play an important pathogenic role such as glomerulonephritis, rheumatoid arthritis and systemic lupus erythematous.