Classification of immune responses by Gel and Coombs
Using the classification developed by Gel and Coombs, immune responses causing immunopathology can be segregated into four main types. What are the four main types?
- Type I: IgE-mediated immediate hypersensitivity (e.g., allergic rhinitis or hay fever)
- Type II: antibody-mediated tissue injury (e.g., autoimmune hemolytic anemia)
- Type III: immune complex (antigen–antibody) formation (e.g., serum sickness, Arthus skin reaction)
- Type IV: delayed-type hypersensitivity (e.g., immune response to mycobacterial antigens, positive purified protein derivative skin test).
A fifth type has been added where antibodies bind to receptor causing overstimulation (e.g., thyroid-stimulating Ig binds to thyrotropin receptor mimicking thyroid-stimulating hormone in Graves’ disease).
