GRAVES DISEASE IN CHILDREN AND ADOLESCENTS

PROGRESSION FROM HYPERTHYROIDISM TO SPONTANEOUS HYPOTHYROIDISM

Abstract

INTRODUCTION
Graves’ disease (GD) is an autoimmune disorder characterized by hyperthyroidism caused by the presence of thyroid stimulating-antibody. In adult patients with GD, approximately 5-20% of patients eventually progress to hypothyroidism after a period of remission of more than 10 years. Possible mechanisms for the development of spontaneous hypothyroidism are the development of TSH-blocking antibodies or a chronic autoimmune process similar to Hashimoto thyroiditis. In children, whether a subset of patients’ progress to hypothyroidism is unclear.

RESULTS
We present three cases of pediatrics GD who progress from hyperthyroidism to hypothyroidism. Case 1: 17-year-old girl. Treated with carbimazole for 6 years. Defaulted follow up for 1 year, self-prescribed carbimazole. Severely hypothyroidism when re-presented (FT4 3.7 pmol/, TSH 179.9 mIU/L). Currently on L-thyroxine 100 mcg daily past 1 year. At presentation TRAb 28.1 U/L (<1), Anti-TG >4000 U/ml (<1), Anti-TPO >929 U/ml (<1). At remission TSI 120 IU/L (<0.55), anti-TG 1313 U/ml(<1), anti-TPO >972 U/ml(<1) Case 2: 11-year-old girl. Treated with carbimazole 3 years. Developed subclinical hypothyroidism (FT4 8.4 pmol/L and TSH 7.455 mIU/mL) after 1 year of remission. Spontaneous normalization of TFT after 2 months currently euthyroid. At presentation TRAb 20 U/L (<1), Anti-TG 1425 U/ml, Anti-TPO >986 U/ml.At remission:TRAb 0.46IU/L(<1) Case 3: 10-year-old girl presented at age of 8 years with weight loss over 4 months. Treated with carbimazole for 1 year. Developed hypothyroidism (FT4 8.9 pmol/L, TSH 13.45 mIU/mL) after 8 months of remission. Currently on L-thyroxine 25 mcg for duration of 3 months. At presentation TRAb 151 IU/L (N<0.55), Anti-TG 408.9U/ml (n<1), Anti-TPO>988 U/ml (N <1). At remission,TRAb 24.2 IU/L(<1),Anti-TG:507 U/ml,Anti-TPO: >986 U/ml.

CONCLUSION
Our cases demonstrate that there are a proportion of children with GD in remission that develop spontaneous hypothyroidism. Highly elevated levels of anti-TPO could be a predictive risk factor for this.