Type III hypersensitivity

Definition

Type III hypersensitivity is an immune reaction where antigen-antibody complexes deposit in tissues, leading to inflammation and tissue damage. It involves immune complex-mediated reactions causing diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis.

5 Must Know Facts For Your Next Test

1. Type III hypersensitivity is also known as immune complex-mediated hypersensitivity.
2. It primarily involves IgG or IgM antibodies forming complexes with antigens.
3. Common sites for immune complex deposition include blood vessels, kidneys, and joints.
4. The activation of the complement system plays a critical role in the resulting tissue damage.
5. Diseases associated with type III hypersensitivity include systemic lupus erythematosus (SLE), rheumatoid arthritis, and post-streptococcal glomerulonephritis.

Review Questions

Related terms

type I hypersensitivity:

An immediate allergic reaction mediated by IgE antibodies.

type II hypersensitivity: A cytotoxic reaction where antibodies target cell surface antigens.

complement system:

A group of proteins that enhance the ability of antibodies to clear pathogens and damaged cells.