Endocrine Abstracts

Introduction: The presence of thyroid peroxidase (TPO) antibodies in euthyroid children poses a potential risk for the development of autoimmune hypothyroidism. Little is known about the ontogeny of this process. This retrospective study aims to estimate the risk of developing hypothyroidism in euthyroid children with raised TPO antibodies and provide a guideline for follow up.

Methods: Children 0–16 years with raised TPO antibodies (1996–2005) were identified from the biochemistry database of a University Hospital. In those that were euthyroid on initial screen, follow up clinical details and thyroid function tests (TFT) were obtained from case records.

Results: Two hundred and eight children were identified with raised TPO antibodies, 164 had concurrent TFT results. 104 were excluded as they either had frank hypothyroidism, compensated hypothyroidism or thyrotoxicosis, leaving 60 euthyroid children (19 males, 41 females). 9/60 had no further follow up results. Within 2 years 2/51 (4%) had developed hypothyroidism requiring treatment. By 5 years a further 2 children had developed hypothyroidism (one had type 1 diabetes (T1DM) and the other Down syndrome). At 10 years another two children were being treated, one with T1DM and one with both T1DM and Down syndrome.

Conclusion: Risk of hypothyroidism in healthy euthyroid children with raised TPO antibodies is minimal after the first 2 years. Therefore a suggested policy of follow up with TFT at 3–6 months and then annually up to 2 years before discharging back to primary care would seem appropriate. However, children with chronic conditions like Down’s syndrome and autoimmune illnesses like T1DM need periodic monitoring.