Final answer:
Type III Hypersensitivity is characterized by immune complex deposition in tissues which leads to complement activation and subsequent inflammatory tissue damage.
Step-by-step explanation:
The mechanism for Type III Hypersensitivity is immune complex deposition. This hypersensitivity involves the interaction of IgG, IgM, and sometimes IgA antibodies with an antigen to form immune complexes. These complexes can accumulate in tissues, particularly in small blood vessels, leading to damage initiated by complement activation and recruitment of neutrophils to the site. Specifically, the damage occurs when these immune complexes deposit in tissues and activate the complement system, setting off an inflammatory response that attracts and activates neutrophils, resulting in tissue damage.
This process can affect various systems and organs, including blood vessels, heart tissue, joints, skin, and kidneys. In severe cases, such as when kidneys are affected, dialysis may be required.