Moderate Frequency of Anti-Thyroglobulin Antibodies in the Early Phase of Subacute Thyroiditis

Abstract

Background: Subacute thyroiditis is generally believed to be induced by viral infection, and little attention has been paid to anti-thyroid antibodies. Objectives: Our study aimed to assess the prevalence of anti-thyroid antibodies in patients with subacute thyroiditis. Methods: Anti-thyroglobulin (TgAb) and anti-thyroid peroxidase antibodies (TPOAb) were measured with 4 different immunoassay kits currently used in 40 patients in the early phase of subacute thyroiditis. Results: The proportion of samples positive for TgAb was 52.5 ± 13.7% (mean of 4 kits), which was significantly (p < 0.05) higher than that positive for TPOAb (15.6 ± 6.5%). The prevalence of positive TgAb alone (negative TPOAb) was also significantly higher than that of TPOAb alone (negative TgAb). TgAb titers decreased or disappeared within 4 months to 6 years in 6 patients. Conclusions: Patient samples were moderately positive for TgAb initially, but the titer decreased or disappeared afterwards in subacute thyroiditis.