What is a type III hypersensitivity reaction?
In type III hypersensitivity reaction, an abnormal immune response is mediated by the formation of antigen-antibody aggregates called “immune complexes.” They can precipitate in various tissues such as skin, joints, vessels, or glomeruli, and trigger the classical complement pathway.
What causes type III hypersensitivity?
Type III hypersensitivity is caused by circulating immunocomplexes (see Fig. 2-29C) and is typified by serum sickness (a drug reaction in which multimeric drug-antibody aggregates form in solution). Preformed immunocomplexes deposit in various vascular beds and cause injury at these sites.
What is a type III hypersensitivity reaction and how does this result in Poststreptococcal glomerulonephritis?
Poststreptococcal glomerulonephritis (PSGN) is characterized by rapid deterioration of kidney functions due to an inflammatory response (type III hypersensitivity reaction) following streptococcal infection.
Is SLE Type 3 hypersensitivity?
SLE is a prototype type III hypersensitivity reaction. Local deposition of anti-nuclear antibodies in complex with released chromatin induces serious inflammatory conditions by activation of the complement system.
Is lupus a type III hypersensitivity?
What are the four major types of hypersensitivity?
The four types of hypersensitivity are:
- Type I: reaction mediated by IgE antibodies.
- Type II: cytotoxic reaction mediated by IgG or IgM antibodies.
- Type III: reaction mediated by immune complexes.
- Type IV: delayed reaction mediated by cellular response.
What are the four types hypersensitivity?
Four different types of allergic reactions are immediate, cytotoxic, immune-complex mediated and delayed hypersensitivity reactions.
Is Celiac Disease Type 3 hypersensitivity?
Celiac disease is sometimes classified as a Type IV hypersensitivity mediated by T-cell responses whereas allergy is usually classed as a Type I hypersensitivity mediated by E-type immunoglobulins (IgE antibodies).
What is the difference between type II and type III hypersensitivity reactions?
Type II hypersensitivity reactions involve IgG and IgM antibodies directed against cellular antigens, leading to cell damage mediated by other immune system effectors. Type III hypersensitivity reactions involve the interactions of IgG, IgM, and, occasionally, IgA1 antibodies with antigen to form immune complexes.
Which of the following autoimmune diseases involves predominantly type III hypersensitivity?
Hence, vasculitis, glomerulonephritis and arthritis are commonly associated conditions as a result of type III hypersensitivity responses.