The Incidence of Thyroid Autoantibody in Subacute Thyroiditis and the Clinical Characteristics of Greeping Thyroiditis / 대한내분비학회지

ABSTRACT

Background: Subacute thyroiditis is a spontaneously resolving inflammatory disorder of thyroid gland, usually associated with painful goiter and short-lived thyrotoxicosis. Although its etiology is yet to be established, much evidence suggests viral infections and genetic factors play important roles. Usually, both lobes of thyroid gland are involved simultaneously, but in some patients one lobe is involved first and the other later(creeping thyroiditis), Thyroid autoantibodies which might appear probably due to inflammatory release of thyroid antigens, are found in a variable number of patients with subacute thyroiditis. However there have been few detailed reports on their incidence in Korean patients with subacute thyroiditis. So, we were to see the elinical characteristics of patients with subacute thyroiditis with special regards to the incidence of thyroid autoantibodies and to the incidence and characteristics of creeping thyroiditis, Methods: We reviewed the clinical records of 85 patients with subacute thyroiditis(7 men and 78 wornen, meam age of 43+9 years) who had visited the thyroid clinic in Seoul National University Hospital between 1986 and 1994. Results: At initial visit, the incidenees of thyroid autoantibodies were as follows anti- microsomal antibody 7.8%, anti-thyroglobulin antibody 22.1%, and thyratropin binding inhibitor inununglobulin 6.3%. During the follow-up period, thyroid autoantibodies appeared most frequently between the first and the second month after initial visit. Compared to those with non-creeping thyroiditis, the patients with creeping thyroiditis(21.4%) had nonspecific systemic sy~rnptoms more frequently(89% vs. 42%, p<0.05). They required steroid therapy more ftequently(89% vs. 52%, p <0.05), and needed longer duration of treatment(9.3+6.2weeks vs, 4.7+3.7weeks, p<0.05). The incidence of abnormalities in liver function and the incidence of thyroid autoantibodies were higher in non-creeping thyroiditis group. Conclusion: In accordance with previous reports, thyroid autoantibodies were detected in only a small portion of Korean patients with subacute thyroiditis. Rather different clinical manifestations and different incidences of thyroid autoantibodies between ereeping group and non-creeping group suggest differences in the pathogenetic mechanisms between those two groups. However, there is need for further study to validate such observation and to elucidate the mechanisms.