The right eyes of guinea pigs were injected with 1.5 mg sterile
ovalbumin. Two months later, one drop of
ovalbumin (approximately 0.6 mg) was applied to the conjunctiva of both eyes. All challenged eyes developed an
immediate hypersensitivity reaction within 5 min. The reaction subsided within 2 hrs. Prechallenge antibody titers, as determined by passive hemagglutination, passive cutaneous anaphylaxis, and by an ELISA test were low. Titers rose rapidly after two conjunctival applications at weekly intervals. The
hypersensitivity reaction was elicited each time
antigen was applied to the conjunctiva of the intravitreally sensitized guinea pigs. Control guinea pigs received weekly conjunctival application of
ovalbumin, without prior intravitreal sensitization. Most animals developed an
immediate hypersensitivity reaction following the fourth application of the
antigen. There was no detectable hemagglutinating or ELISA (
IgG1,
IgG2) antibody at the time the conjunctival reaction was first elicited. These experiments demonstrated that high circulating
IgG1 or
IgG2 antibody is apparently not necessary to initiate an
immediate hypersensitivity reaction in the guinea pig conjunctiva. The authors also demonstrated that weekly topical application of
ovalbumin sensitized guinea pigs for
immediate hypersensitivity.