Chapter 17, Problem 4MC

Summary Introduction

Introduction:

Type III hypersensitivities involved immune complex formation that consists IgM and IgG antibodies with soluble antigens. These complexes are removed from the bloodstream by phagocytosis if these are of large size. However, if the antigenis more than antibodies, then small complexes will form these cannot be destroyed but circulate in the blood or remain in tissues.

Circulating ones can block the lining of blood vessels and accumulate in capillary regions of skin, kidney, joints, and other tissues. They can activate the complementsystem, recruiting the neutrophils and releasing pro-inflammatory cytokines. They are responsible for many diseases such as rashes, joint’s pain lupus erythematous, and glomerulonephritis.