Endocrine Abstracts

Introduction

Diagnostics of thyroid dysfunctions is frequently based on the measurements of TSH serum concentration only. Currently, due to a tendency to minimize stressful situations for a child (such as venipuncture to take a blood sample), some tests (i.e. TSH assessment) are performed at the Primary Healthcare Centre while other diagnostic tests (e.g. during an infection) are run. If TSH serum concentration is outside the reference range, it leads to the implementation of the diagnostic procedure used in patients with a thyroid disorders. Clinical observations indicate that in a considerable number of these patients, a thyroid disease is not confirmed, and the results of the tests performed so far are in fact falsely positive. The aim of the study was to assess the incidence of transient hyperthyrotropinemia during acute infections of the respiratory system in generally well-being children without previously diagnosed thyroid disease.

Material

The study group consisted of 94 children (49 boys and 45 girls), aged 2.2–17.3 years, who were consecutive admitted to a single Primary Healthcare Centre due to acute respiratory infection during one year. Obese and undernourished children were excluded from the study, similarly to patients treated for thyroid diseases and those who displayed typical signs and symptoms of thyroid disorders. In every case, a complete blood count (CBC) test was performed and C-reactive protein (CRP) as well as TSH in serum was measured. The tests were run on the next day after the visit (at the morning after an overnight fasting). Next, the parents were asked to bring the child for a check-up examination ≥ 2 weeks after recovery. At the next visit, the patient’s condition was evaluated again and a blood sample was taken in order to assess the same parameters: CBC, CRP and TSH.

Results

Among these children manifesting both with or without fever, regardless of the elevated CRP concentration and of the type of infection (viral or bacterial), elevated TSH values are found in about 10% of patients, and they go back to normal values after resolution of symptoms. A prospective analysis showed a reduction of TSH values in approx. 65% of all examined children, and the TSH results at the control time point were significantly lower than during acute infection.

Conclusion

It seems that TSH levels should not be assessed during an acute infection. If thyroid dysfunction is suspected, the examination should be performed in the healthy state.