Clinical Features and Predictors of Remission in Children Under the Age of 7 Years with Graves' Disease

Importance: Graves' disease (GD) is rare in children under the age of 7 years. Children with this disease exhibit greater thyrotoxicity at diagnosis and require a longer course of medical therapy, compared with pubertal and postpubertal children and adults.

Objective: To investigate the clinical features and identify predictors of remission in children under the age of 7 years with GD.

Methods: This retrospective study included 77 children who were diagnosed with GD under the age of 7 years and were treated in the Department of Endocrinology, Beijing Children's Hospital from 2010 to 2018. Clinical manifestations, laboratory data, and follow-up records were collected for all patients. Children who achieved remission of treatment with methimazole were compared with those who had persistent disease to identify which variables were associated with remission; multiple logistic regression and Cox regression analyses were used to evaluate interactions among predictive variables.

Results: Sixty-three boys and 14 girls were included; the median age at diagnosis was 4.2 years (interquartile range: 3.2-5.3 years). Forty-six (56.7%) patients had no family history of thyroid disease, 17 patients had family history of thyroid disease and 14 patients with unknown family history. Of the 77 patients, 18 (23.4%) patients achieved remission of treatment with methimazole and 59 patients did not; moreover, 51 (66.2%) had Graves' ophthalmopathy. Univariate analyses revealed no significant differences between the remission group and non-remission group in terms of age at diagnosis, sex, initial goiter size, or initial thyroid hormone concentration. However, there were a trend of correlation between the initial level of thyroid peroxidase antibody (TPOAb) and remission status (univariate analysis 1.002, 0.038; multivariate analysis 1.004, 0.019). Similar results were observed in univariate analysis of the initial thyrotropin receptor antibody (TRAb) level, but this association was not significant in multivariate analysis. Cox regression analyses revealed that children with high TRAb level required longer duration of remission, compared with low TRAb level ( 0.950, 95% 0.904-0.997, 0.037).

Interpretation: Initial TRAb level was an independent predictor of remission outcome in young children under the age of 7 years with GD. Initial TRAb level may predict the likelihood of remission in patients with young-age-of-onset GD.