Long-term observation and effect of age on induction of experimental autoimmune thyroiditis in susceptible and resistant mice.

After induction of experimental autoimmune thyroiditis (EAT) in mice, long-term observation on both the severity of thyroiditis and antibody formation against mouse thyroglobulin (MTg) was carried out over a period of 18 months. In EAT-susceptible strains (CBA, C3H/Anf), both the severity of thyroiditis and MTg antibody production continued for a long term. In EAT-resistant mice (BALB/c), thyroiditis remained minimal, if present, and the low antibody response to MTg became negligible. On the other hand, aging had a prominent effect on the EAT induction in susceptible mice; both MTg antibody response and thyroid infiltration were markedly reduced. These data were well correlated with reduced antibody formation against sheep red blood cells. Young and old mice were further compared as donors or recipients in adoptive transfer of concanavalin A-stimulated cells. Lymph node cells from either young or old MTg-immunized mice transferred appreciable thyroiditis to normal young and old recipient mice. However, similarly treated spleen cells from MTg-immunized old mice responded more poorly to in vitro stimulation with mitogens or MTg and transferred thyroiditis to very few normal young or old mice.