The Effect of Radioiodine Treatment on TRAb, Anti-TPO, and Anti-TG in Graves’ Disease

Abstract

Background: In Graves’ disease (GD), immunocompetent cells infiltrate thyroid tissue with release of TSH-receptor antibodies (TRAb), and radioiodine treatment is known to elicit an immune response with an increase in TRAb. Objectives: The aim was to study if all patients treated with radioiodine respond with a release of TRAb, anti-thyroperoxidase (anti-TPO), and anti-thyroglobulin (anti-TG). Methods: This is a prospective observational study. GD patients (n = 131) were admitted for treatment with radioiodine. Thyroid antibodies were measured before and 3 months after iodine-131 treatment. Results: After 3 months, a fold change > 1.1 was found in 66% of the GD patients, while the remaining 34% did not have a change or decrease in in TRAb. Anti-TPO and anti-TG also increased; the former showed an increase in 73% and the latter of 52%, while 27 and 48% decreased/were unchanged. A significant positive correlation was found between TRAb and anti-TPO, but not between TRAb and anti-TG. In the group with an increase in TRAb, the median fold change was 5.1, but there were no additional effects of tobacco smoking. The proportion of females below the median age (51.5 years) was significantly higher in the group that increased in TRAb compared to the one that decreased/was unchanged (66 vs. 34%). Conclusions: Treatment with radioiodine elicits an increase in thyroid antibodies, but not in all GD patients. The proportion of responders varied and was affected by age, resulting in a stronger immune response at younger age. However, there were no additional effects of smoking.

Remission Rate of Graves' Disease and the Trend of Changes in Serum TSH Receptor Antibodies in Prolonged Antithyroid Drug Treatment

“…These findings were confirmed by other studies (24), and these peaks were correlated with the development of GO (12,26). TRAb remaining positive after years may 2…”

“…The use of ATD is accompanied by a series of markers demonstrating immune system restoration, such as decreased HLA in thyroid cells (17), and decreased markers of inflammation, such as Interleucines 1, 5, and 6 and tumor necrosis factor-alpha (18,19). There are also increases in T cell suppressors, decreases in T helper cells (20), and decreases in TRAb values over time (9,10,(21)(22)(23)(24).…”

Increased Risk of Graves´ophthalmopathy in Patients With Increasing TRAb After Radioiodine Treatment and the Impact of CTLA4 on TRAb Titres

“…We have shown that 3 months after treatment with radioiodine, two groups of patients were identi ed according to antibody response, one group that did not increase in TRAb, anti-TPO and anti-TG (approximately 30 % of the patients) and one group that increased in antibodies (approximately 70% of the patients). This has previously been demonstrated in a smaller group of GD patients [15]. The second observation was that the risk of developing GO was clearly elevated in patients which increased in TRAb 3 months after radioiodine.…”

“…In vitro it has been shown that a mixture of immunocompetent cells in Hashimoto produces thyroid speci c antibodies after irradiation, and this effect was dose dependent [11]. We have previously studied the effect of the dose of radioiodine, but we could not con rm this in vivo [15]. Another hypothesis is that a transient increase in thyroid antigen like thyroglobulin will be released when cells are destroyed by irradiation [9,10].…”

“…In a previous study on the treatment of GD patients with radioiodine we have de ned one group with increases in TRAb, thyroid peroxidase antibodies (anti-TPO), thyroglobulin antibodies (anti-TG), and another group with no increase of these thyroid antibodies after treatment with radioiodine [15]. We have now increased the number of patients and followed these patients for at least 1 year.…”