Massive follicular lymphoid hyperplasia in experimental allergic conjunctivitis. Local antibody production

Acute and recurrent allergic conjunctival reactions were induced in guinea pigs by repeated conjunctival applications of fluoresceinyl ovalbumin (FL-OA) for up to 30 months. Early type I conjunctival reactions developed 11 to 25 days after the initial conjunctival exposure to FL-OA. Continuous topical challenges during a six- to 30-month period caused a variety of reactions, including papillary changes and massive hyperplasia of the conjunctival-associated lymphoid tissues. Hyperplasia of lymphoid tissues was induced during a shorter period (two to five months) with a mixture of FL-OA and phorbol ester. Culture fluid from hyperplastic conjunctival lymphoid tissue showed a ratio of IgG1/IgG2 antibody production of up to 15. A low level of recurrence of type I reactivity, after an initial desensitization phenomenon due to a loss of reactive mast cells, correlated with prominent follicular hyperplasia of the conjunctival-associated lymphoid tissue.