ESPE Abstracts

Introduction: PGD is characterized by hyperthyroidism and antibodies against the TSH receptor (TSHRAB). Reported annual incidence is 4,58/100,000.

Objective: To describe an Argentinean cohort with PGD followed between 2006 and 2020 at the Ricardo Gutierrez Children’s Hospital.

Material and Methods: Retrospective study of 69 patients, who were treated initially with antithyroid drugs (ATD) in a titration dose regimen with a median (range) time of follow up of 4,61 years (0,28-11,58). Demographic, clinical, biochemical and treatment data were collected from clinical charts. Factors thought to predict outcome (age, sex, pubertal status, goiter, ophthalmopathy, family history of thyroid disease, free thyroxine (FT4) and TSHRAB) were analyzed with Student t-test for continuous variables, and the Fisher’s exact test for categorical variables (significance: P< 0,05)

Results: At diagnosis median age was 12,3 years (1,7-17,2), 75% were girls, 65% pubertal. 71% had goiter ≥ 2 (OMS classification), 65% ophthalmopathy and 46% had a positive family history of thyroid disease. 85% had free thyroxine (FT4) > 50pmol/l (3,9 ng/dl) and 83% TSHRAB ≥ 3-folds upper normal limit of our assay. Goiter, ophthalmopathy and tachycardia were the main clinical signs observed. Median methimazole (MMZ) starting dose was 0,84 mg/kg (0,4-1,3). 20% of the patients presented adverse effects (AEs) related to the drug, 79% in the first 5 weeks of treatment and 71% were severe enough to discontinue ATD. The overall remission rate with a median of ATD of 3.29 years (1,3 -6,1) was 14% (n=10). 13% are still receiving ATD. Older patients (P< 0,02) and patients with TSHRAB below 3 folds upper limit of our assay (P< 0,01) were more likely to respond to ATD. Because of AEs, thyroid nodules, relapse, and flare-ups, 51% of patients underwent definite treatment: 54% radioiodine ablation, and 46% total thyroidectomy. 22% of the total cohort was lost to follow up, 9% in the first two years of ATD.

Conclusion: Our cohort presented severe cases of PGD. This approach implied long-term treatment and controls. Remission rate at approximately 3 years of treatment was low and 22% dropped out, unable to follow our recommendations and half of the cohort needed definite treatment. These results may lead us to reconsider our approach to severe PDG focusing on other factors associated with outcome such as compliance and social background and perhaps opting earlier for a definitive treatment as an alternative to ATD.