THE COURSE OF EXPERIMENTAL AUTOALLERGIC THYROIDITIS IN INBRED GUINEA PIGS

Abstract

Allergic thyroiditis in . histocompatible guinea pigs was produced after a single immunization with thyroid extract and Freund''s adjuvant. It appeared at 5 days, reached a maximum at 7 weeks, and persisted for more than 2 years. Circulating antibody appeared at low levels at 7 days, reached a peak at 7 weeks, and decreased thereafter to low levels by 2 years. A positive correlation between antibody titer and degree of disease was present only at the 7 weeks stage. Delayed sensitivity to thyroid appeared at 5 days, and appeared to precede thyroiditis in many animals. Delayed sensitivity correlated closely with thyroiditis at 5 days and 7 weeks. It decreased by 6 months, and a modified "intermediate" skin reaction appeared at 6 months and persisted as long as 26 months. The role of delayed sensitivity in the pathogenesis of this autoallergic disease is confirmed by the time relationship of delayed sensitivity, thyroiditis, and circulating antibody. The production of thyroiditis without antibody and of antibody without thyroiditis adds further evidence to this hypothesis.