VMC 221: Veterinary Immunology and Serology (1+1)

Local type III reaction or Arthus Phenomenon

ARTHUS REACTION

• If an antigen is injected subcutaneously into an animal that already has precipitating antibodies, then acute inflammation will develop at the injection site within several hours. This is called Arthus reaction.
• It starts as an erythematous, edematous swelling, eventually local hemorrhage and thrombosis occur and, if severe, end in local tissue destruction.
• The antibodies involved in Arthus reaction must be both precipitating and complement activating and are usually of the IgG class.
• A reversed Arthus reaction can be produced if antibodies are given intradermally to an animal with a high level of circulating antigen. Eosinophil infiltration is not a significant feature of this type of hypersensitivity.
• The immune complexes are deposited between and beneath vascular endothelial cells.
• A reversed Arthus reaction can be produced if antibodies are given intradermally to an animal with a high level of circulating antigen, which results in similar reaction.
• A passive Arthus reaction can be produced by giving antibody intravenously and antigen intradermally.
• Reverse passive Arthus reaction can be produced by giving antigen intravenously and antibody intradermally.
• Examples
  • Blue eye
  • Hypersensitivity pneumonitis