Endocrine Abstracts

Objectives: To identify clinical features, biochemical thyroid function and thyrotrophin receptor antibody (TRAb) concentrations at first presentation of Graves’ disease (GD), and their relationship to outcome (relapse, REl; remission, REM) after stopping anti-thyroid drug (ATD) treatment.

Methods: A retrospective analysis of the Thyroid Clinic electronic database was carried out, of all subjects at first presentation of GD between 2006-2012. TRAb concentrations, clinical and biochemical parameters were compared between the REL and REM groups after stopping ATD therapy. The follow up period was 11-17 years.

Results: Data from 399 subjects (322 women and 77 men) were available for analysis. During the follow up period, 205 (51%) had a relapse (77.5% females) and 194 (49%) remained in remission (84% females). In the REL group, TRAb concentrations (7.9 vs. 5.85 IU/l, P = 0.03) and goitre prevalence (58.4 vs. 46.4%, P = 0.02) were significantly higher compared to the REM group. Demographic and biochemical features were not significantly different between the groups.

Furthermore, in the REL group –

(i) 70% of subjects relapsed within one year of stopping ATD

(ii) median TRAb concentrations were significantly higher in those who relapsed within one year compared to those who relapsed later (10 vs. 6.25 IU/l, P = 0.005)

(iii) time to normalization was 11 vs. 8 weeks (P < 0.001) compared to REM group

(iii) however, sex, the presence of a family history, age, smoking and orbitopathy were not significantly different (P = 0.1-0.54)

Conclusion: We conclude that GD subjects who relapsed–

1. Had significantly higher TRAb concentrations and goitre prevalence at presentation (P < 0.03)

2. 70% of them did so in the first year after stopping ATD (TRAb concentration significantly higher compared to those who relapsed later, P < 0.005)

3. Took a significantly longer time to normalization of thyroid function (P < 0.001)

4. Did not show any significant association with other demographic, biochemical or clinical features