[The clinical course of Hashimoto's thyroiditis during a 5 year observation period in relation to the change in thyroid function and the titers of the antithyroid antibody].

In order to discover whether or not thyroid function in patients with Hashimoto's disease will move toward hypothyroidism with age, we investigated the thyroid function and antithyroid antibody titers at the initial examination and 5 years later in 181 patients with goitrous Hashimoto's thyroiditis. Pregnant patients and those within 1 year of the postpartum period were excluded. The thyroid function was assessed before medication or at least one month after stopping it. At the initial examination, 52% (94 cases) of the cases were euthyroid, 24% (44 cases) were subclinically hypothyroid and 24% (43 cases) were hypothyroid. It was not observed whether the incidence of hypothyroidism tended to be greater in older patients or in patients with longer duration of illness. Five years later, 68% of euthyroid patients at the initial examination remained in euthyroid state, 18% had become subclinically hypothyroid, and 9% were hypothyroid. The thyroid function was not evaluated in 5% of the patients because they were under treatment with 1-thyroxine. In the patients with subclinical hypothyroidism at the initial examination, 30% had become euthyroid, 23% remained subclinically hypothyroid, 32% had become hypothyroid and 16% were not evaluated. Thirty percent of the patients with hypothyroidism at the initial examination had become euthyroid, 7% were subclinically hypothyroid, 28% remained hypothyroid and 35% were not evaluated. The higher the titer of TGHA, the higher the percentage of hypothyroidism at the first examination. A similar but much stronger tendency was observed in the patients with a higher titer of MCHA. In the patients with a higher titer of TGHA, the number of hypothyroid patients approximately doubled after 5 years, although such a tendency was not observed in the patients with a higher titer of MCHA. In patients with persistent hypothyroidism, the age was significantly higher, the serum concentration of T3 lower and the titer of TGHA at the initial examination and MCHA 5 years later higher than in the patients with transient hypothyroidism. The titer of MCHA was significantly decreased 5 years later in patients with transient hypothyroidism. From these results, it is indicated that in patients with goitrous hypothyroidism, the incidence of hypothyroidism was higher in the cases with high titers of antithyroid antibody than in those with low titers, and that in the patients with transient hypothyroidism, the age was lower, the serum level of T3 higher and the titer of TGHA lower than in the cases with permanent hypothyroidism.(ABSTRACT TRUNCATED AT 400 WORDS)