Thyroid Antibody Levels Not Predictive of Clinical Manifestations of Graves’ Disease

Thyroid autoantibodies do not predict clinical features of Graves’ disease and therefore have little bearing on patients’ treatment decisions, according to data presented at the 84th Annual Meeting of the American Thyroid Association.

Dawn Elfenbein, MD, PhD, of the University of Wisconsin in Madison, and colleagues previously found an association between socioeconomic factors and clinical manifestations of disease and whether a patient opts for thyroidectomy or radioactive iodine as primary treatment for Graves’ disease.

To determine whether thyroid autoantibody levels can predict clinical manifestations of the disease, the researchers conducted a retrospective review of more than 450 patients who underwent radioactive iodine therapy (71%) or thyroidectomy (29%) during a 6-year period.

Results indicated a significant increase, from 14% in the first year of the study to 52% in the final year, in the percentage of patients who underwent surgery (P<.01).

Of all patients included in the study, 52% had thyroid peroxidase (TPO) measured before treatment; 44% had thyroglobulin (TgAb) measured and 45% had either thyroid stimulating immunoglobulin (TSIg) or thyrotropin receptor antibody (TRAb) measured.

The researchers found that those who underwent surgery were more likely to have measurements of any antibodies vs. those who underwent radioactive iodine therapy (P<.01).

Additionally, the likelihood of having eye disease was more common in patients with a positive TSIg or TRAb (40% vs. 25%; P=.04), while likelihood of having goiter was increased in those with positive TgAb (70% vs. 55%; P=.03) on bivariate analysis. Nevertheless, antibody positivity was not associated with ophthalmopathy or goiter on multivariate analysis.

“Clinical features such as ophthalmopathy or compressive goiter are often the driving factors behind patients’ treatment choices, and measurement of thyroid-specific autoantibodies does not appear to be predictive of these clinical features,” the researchers wrote.

Reference

1. Elfenbein D et al. Poster 228. Presented at: American Thyroid Association (ATA) 84th Annual Meeting; Oct. 29-Nov. 2, 2014; Coronado, Calif.