Successful radioiodine treatment in a 3 year old child with Graves' disease following antithyroid medication induced neutropenia

Graves' disease in a five-month-old boy with an unusual treatment course

OBJECTIVES

Graves' disease (GD) is rare in children under age five years. Antithyroid drugs are typically first-line therapy but carry the risks of agranulocytosis and liver dysfunction.

CASE PRESENTATION

A male infant with multiple congenital anomalies, left ventricular hypertrophy, and neurologic dysfunction developed GD at five months of life. The presence of chronic hepatitis complicated medical management. Potassium iodide was effective temporarily, but urgent thyroidectomy was required at nine months of age. Postoperatively, the patient developed a thyroid function pattern consistent with impaired pituitary sensitivity to thyroid hormone (TH) that responded to the addition of liothyronine. Exome sequencing revealed a heterozygous de novo duplication of the ATAD3 gene cluster, suggesting a possible mitochondrial disorder.

CONCLUSIONS

This case describes the youngest child to date to be diagnosed with endogenous GD and to successfully undergo definitive treatment with thyroidectomy. An underlying defect in mitochondrial function is suspected, suggesting a potential novel pathophysiologic link to early-onset thyroid autoimmunity. Additionally, this case illustrated the development of impaired pituitary sensitivity to TH following thyrotoxicosis of postnatal onset, which may contribute to our understanding of hypothalamic-pituitary-thyroid (HPT) axis development.

A 3-year-old girl with Graves' disease with literature review

Graves' disease, the main cause of hyperthyroidism in the pediatric age group, is very rare in children younger than 4 years old but can seriously interfere with growth and development if not recognized and treated. Here we report a case of a 3-year-old girl with Graves' disease who presented with goiter, exophthalmos, heat intolerance, and hyperactivity. At her first visit, her serum concentrations of triiodothyronine (T3) and free thyroxine (free T4) were normal, whereas that of thyroid-stimulating hormone (TSH) was decreased. Antimicrosomal antibody was 7,053.94 IU/mL, and TSH-binding inhibitory immunoglobulin was 31.62%. A thyroid scan showed diffuse enlargement with markedly increased uptake of both thyroid glands. Although T3 and free T4 levels were initially normal, she developed hyperthyroidism 3 months later. She was finally diagnosed with Graves' disease and treated with methimazole for 6 months. This is the first report of Graves' disease in children younger than 4 years old in Korea.

Clinical course of pediatric and adolescent Graves' disease treated with radioactive iodine

The use of radioactive iodine (RAI) therapy in children and adolescents with Graves' disease is increasing; however, few data exist to guide dosing in this population. We aimed to determine the clinical course, failure rate and factors associated with failure of RAI for pediatric Graves' disease. A retrospective chart review from a tertiary care pediatric endocrinology clinic (1990-2003) identified 22 patients (12.7 +/- 4.0 years at diagnosis) with Graves' disease treated with RAI after initial pharmacological therapy. Patients received a calculated dose of RAI (0.1 mCi/g thyroid tissue, adjusted for 6-h radio-iodine uptake). Twenty-seven percent (95% CI 11-50%) remained hyperthyroid and required a second dose. If the first RAI was successful, the average time to hypothyroidism was 2.96 +/- 1.05 months. There were no statistically significant differences between those successfully treated with one dose and those requiring re-treatment. This high failure rate indicates a need to examine dosing of RAI in this age group.

Graves' disease in children and adolescents: response to long-term treatment

BACKGROUND

Optimal treatment of Graves' disease in paediatric patients is still a matter of controversy. Antithyroid drugs, radioiodine and thyroidectomy are the three therapeutic options available.

AIM

To report our experience of long-term medical treatment and outcome of paediatric Graves' disease.

METHODS

A 5-y-long medical protocol was implemented in 20 children and adolescents with Graves' disease. All patients received antithyroid drugs as the first therapeutic option; patients who did not enter long-term remission received I(131) and/or surgery as the definitive treatment.

RESULTS

The mean age at diagnosis was 12.1+/-4 y. Only two patients were males, both presenting concomitant type 1 diabetes. Mean follow-up was 13.8+/-5.5 y. Forty per cent of patients achieved long-term remission with low antithyroid drugs doses (mean treatment time: 5.4+/-1.4 y). Six patients received I(131) as definitive treatment and another six underwent surgery after completing medical treatment for 6.8+/-4.1 and 5.1+/-2 y, respectively. No patients requiring high antithyroid drugs doses to maintain euthyroidism reached long-term remission and needed I(131) and/or surgery.

CONCLUSION

Implementation of a long-term antithyroid drug protocol achieved 40% long-term remissions in paediatric patients with Graves' disease. Need for maintained high doses of antithyroid drugs could be considered a predictive factor for no remission. When permanent remission was not obtained by medical treatment, I(131)and/or surgery allowed healing in all cases.

Enfermedad de Graves-Basedow en el niño preescolar

Graves' disease, which is the main cause of hyperthyroidism in the pediatric age group, is very rare in pre-school children. We describe the cases of four girls, aged less than 6 years old, out of a total of 30 patients diagnosed with Graves' disease between 1985 and 2004. Investigations were motivated by tachycardia, chronic diarrhea, language development delay or thyroid nodules detected by cervical ultrasonography. In three of the four patients height and bone age were advanced. In all patients goiter was small or absent. None of the patients had ophthalmic disease. In all patients free T3 and T4 were elevated and thyroid-stimulating hormone was suppressed. Three patients were positive for thyroid-stimulating immunoglobulins (the method was not available for the oldest case). Two patients showed complete resolution after 5 years of treatment with carbimazole. The remaining two patients are still under treatment and no adverse effects have been documented.

Juvenile thyrotoxicosis; can we do better?

Thyrotoxicosis remains a frustrating condition for the young person, family, and health professionals involved. The associated symptoms do not always suggest thyroid disease and patients can be unwell for many months before the diagnosis is made. The antithyroid drug regimen used to treat children and adolescents with thyrotoxicosis varies from one unit to another and yet the potentially life threatening side effects and remission rates post-treatment may be related to the regimen used. Most patients with thyrotoxicosis will need many years of drug therapy if the thyroid gland is not removed surgically or destroyed by radioiodine. Even "definitive" treatment will typically necessitate thyroxine replacement for life.