Persistent remission of Graves` disease or evolution from Graves' disease to Hashimoto's thyroiditis in childhood - a report of 6 cases and clinical implications.

BACKGROUND: The main clinical manifestations of autoimmune thyroid diseases are Graves' disease (GD) and Hashimoto's thyroiditis (HT). Graves' disease is the cause of most cases of hyperthyroidism in childhood. Indications for radical therapy (surgery or 131I treatment) in children are still a matter of discussion, as sustained (sometimes very long) remission of GD is possible, while the radical therapy almost always leads to hypothyroidism. Spontaneous evolution from GD with hyperthyroidism to HT with hypothyroidism may also be observed.

OBJECTIVE: The aim of the study was to analyze the clinical course of 6 cases of hyperthyroid girls with GD in whom a normalization of previously increased autoantibodies against thyrotropin (TSH) receptor (anti-TSHR) was observed together with a significant increase in autoantibodies against thyroid peroxidase (anti-TPO) and thyroglobulin (anti-Tg), with concomitant hypo- or euthyroidism but no recurrence of hyperthyroidism.

SUBJECTS: Patients' age at diagnosis ranged from 5.0 to 16.5 years. Two (2) patients had Turner syndrome, another one (1), diabetic, was on insulin therapy.

RESULTS: In all the girls, antithyroid drugs were administered and euthyroid state was achieved during the first 2.0-3.5 months of the treatment. Mild side effects were observed in only one case. The therapy was continued up to 1.5-4.0 years. Relapses during the therapy were observed in 2 cases. Up to now, no relapses have been observed for 0.5-7.5 years since the therapy withdrawal in 5 patients (1 patient was lost to follow-up), 2 patients are currently treated with levothyroxine due to hypothyroidism.

CONCLUSIONS: It seems that the prolonged pharmacotherapy with antithyroid drugs, followed by observation after remission of hyperthyroidism, may be an appropriate therapeutic option at least in some children with GD as they can be cured without radical therapy and the potential risks of such treatment.