Thyroid Research Thyroid Research Archive Nodular Goiter

Radioiodine therapy may induce thyrotropin receptor antibodies in patients with toxic nodular goiter

(July 2002)

The background of the study. Radioiodine is an effective therapy for patients with hyperthyroidism caused by a nodular goiter, but it can result in the production of thyroid antibodies. In this study several antithyroid antibodies were measured before and after radioiodine therapy in patients with hyperthyroidism caused by a nodular goiter.

How the study was done. The study subjects were 41 patients with hyperthyroidism caused by thyroid nodular disease who were treated with radioiodine. Twenty patients had a solitary thyroid adenoma, and 21 patients had a multinodular goiter (the pattern of uptake was patchy or uneven in 11 patients and localized in multiple discrete nodules in 10 patients). Serum antithyroid peroxidase antibodies, antithyroglobulin antibodies, and thyrotropin (TSH)-receptor antibodies were measured before and 3 to 11 months after radioiodine therapy.

The results of the study. Before therapy, none of the patients had any TSH receptor antibodies. After therapy, 4 patients, all in the group of 11 patients with a patchy multinodular goiter, had a high serum concentration of these antibodies. Several patients had high serum antithyroid peroxidase and antithyroglobulin antibody concentrations before therapy, and they and one other patient had high concentrations after therapy.

Among the 10 patients with multiple discrete nodules and the 20 patients with a solitary thyroid adenoma, only 2 in each group had a high serum concentration of thyroid antibodies before or after therapy.

The conclusions of the study. Patients with hyperthyroidism caused by a patchy nodular goiter may have increase in serum TSH receptor antibody concentrations after radioiodine therapy, suggesting that they have preexisting Graves' disease.

The original article. Wallaschofski H, Muller D, Georgi P, Paschke R. Induction of TSH-receptor antibodies in patients with toxic multinodular goitre by radioiodine treatment. Horm Metab Res 2002;34:36-9.