Factors at onset predictive of lasting remission in pediatric patients with Graves' disease followed for at least three years.

Seventeen pediatric patients (mean age at diagnosis 10 yr and 9 mo +/- 2 yr and 9 mo) with Graves' disease treated with 0.3-0.7 mg/kg/day methimazole and followed for at least three years, during which drug suspension was attempted on attainment of good clinical and metabolic compensation, were retrospectively studied to look for factors predictive of lasting remission present at onset. Lasting remission was defined as a clinical and laboratory picture of euthyroidism lasting at least one year in the absence of treatment at the end of the follow-up. A distinction was drawn between patients who reached remission after one or two courses (groups 1 and 2) and those who never attained a lasting remission (group 3). TRAb (TBIAb) levels at onset were the only factor significantly correlated with the response to treatment. Age at diagnosis, goiter size and fT3 and fT4 concentrations were not significantly correlated with the clinical picture. The series was too small to allow any assessment of the real importance of these factors, though a generally better response was displayed by children over 11 years old, without appreciable or with very small goiter and moderately increased thyroid hormone levels at onset (fT3 < 25 pg/ml in 10/10 in groups 1 and 2 and 2/7 in group 3 patients; fT4 < 40 pg/ml in 7/10 in groups 1 and 2 and 3/7 in group 3 patients). It was also found that better results were obtained when the initial drug course was protracted for at least two years.