A Quantitative Study of the Passive Arthus Reaction in the Rabbit Eye

Summary

A typical Arthus reaction may be induced in the rabbit uveal tract by the simultaneous injection of adequate amounts of antigen (crystalline egg albumin or bovine γ globulin) into the anterior chamber or the vitreous and of homologous rabbit antibody intravenously. The reaction is an acute, fibrinous, hemorrhagic uveitis which reaches its peak in less than 24 hr and subsides rapidly. Maximal and minimal reactions required respectively 12 mg and about 1 mg of antibody N (when both eyes reacted simultaneously). Reversed reactions (maximum and minimum) were produced with 0.24 and 0.03 mg approximately of antibody N given in the eye at the same time as intravenous antigen. It was possible to produce both direct and reversed reactions with diphtheria toxoid and horse antitoxin at comparable levels.

When antigen or antibody was injected into the vitreous, it persisted for several days. These substances, however, disappeared rapidly from the anterior chamber. Direct reactions elicited one or more days after antigen injection into the vitreous were increased in intensity and occurred with unusually low levels of intravenous antibody. This did not happen with the reversed reaction. Evidence is presented to show that the enhancement might be due to localization or fixation of antigen in a more reactive site.

Attempted direct and reversed reactions in the cornea failed completely to produce either a typical Arthus response or a delayed opacity comparable to that resulting from local tuberculin injection in a tuberculin-sensitive rabbit. Instead there occurred an iridocyclitis comparable to that which occurred with vitreous or anterior chamber injections.

Arthus reactions were readily produced in the conjunctiva and were accompanied by the formation of a plasmoid aqueous comparable to that seen following the subconjunctival injection of glycerine or hypertonic saline solution.

It did not prove possible to produce a reaction of the wheal and flare type by local sensitization with small amounts of antibody and the later intravenous injection of antigen.

These findings in the rabbit are contrasted with the results of similar experiments in the guinea pig, in which neither an Arthus nor a wheal and flare type of response could be produced by antigen and homologous rabbit antibody injected in various doses and sites and at various intervals in time. Histamine in the anterior chamber of the guinea pig eye gave a well defined reaction.