Type III hypersensitivity reactions are mediated mainly by which type of immune response?

Type III hypersensitivity reactions, also known as immune complex-mediated hypersensitivity, principally involve the formation of antigen-antibody complexes that precipitate in tissues and trigger inflammatory responses. The immune response primarily mediating these reactions includes the activity of neutrophils.

When antigen-antibody complexes are formed, they can deposit in various tissues, leading to local inflammation. Neutrophils are recruited to the site of these deposits and are activated by the presence of the immune complexes. They release enzymes and reactive oxygen species as part of the inflammatory process, which can result in tissue damage and inflammation seen in conditions such as serum sickness, systemic lupus erythematosus, and other autoimmune disorders.

Understanding the role of neutrophils in type III hypersensitivity is essential for recognizing how this immune response can lead to clinical manifestations and diseases associated with it. This complements the broader understanding of the immune system and its reactions, emphasizing the importance of neutrophils in specific types of hypersensitivity reactions.