Medical Definition of Arthus reaction
1.
An inflammatory reaction due to localised injection of an antigen into an animal that has circulating IgG antibodies against that specific antigen. It is evidence of prior exposure to the antigen.
It results in immediate hypersensitivity producing erythema, oedema, haemorrhage, and necrosis and is caused by the deposition of antigen-antibody complexes in tissue spaces and in blood vessel walls that activate complement, most of the damage seemingly being due to the polymorphonuclear leukocytes that phagocytise the deposits and release lysosomal enzymes.
The phenomenon, described by Arthus, was in rabbits, but similar reactions (Arthus-type reactions) are observed in guinea pigs, rats, and dogs, as well as in humans.
See: immune complex disease, Arthus, Nicolas.
(05 Mar 2007)
Lexicographical Neighbors of Arthus Reaction
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