Thyroglobulin and other laboratory diagnosis parameters in treating hypothyroidism in children


Authors: R. Bílek;  M. Dvořáková
Authors‘ workplace: Endokrinologický ústav, Praha
Published in: Čes-slov Pediat 2018; 73 (2): 72-78.
Category: Original Papers

Věnováno významnému životnímu jubileu prof. MUDr. Lidky Lisé, DrSc.

Overview

Objective:
This work discusses thyroglobulin as an appropriate indicator of physiological and pathophysiological processes taking place in the thyroids of six child patients with thyroid hypofunction who were monitored at the start of treatment and during the 3–5 month intervals for a period of 2–3 years in both the clinical examination and the entire laboratory diagnosis of thyroid function, ie. thyrotropin (TSH ), free thyroxine (FT4) and triiodothyronine (FT3), total thyroxine (T4) and triiodothyronine (T3), reverse triiodothyronine (rT3), thyroglobulin (Tg), thyroid binding globulin (TBG), autoantibodies to Tg (antiTg), thyroid peroxidase (antiTPO), TSH receptor (antiTSHr) and urinary iodine were determined.

Patients:
Two out of 6 pediatric patients (4 girls and 2 boys aged 9–14 years) had chronic autoimmune thyroiditis diagnosed leading to hypothyroidism, where, in addition to high autoantibodies to Tg and TPO, TSH receptor autoantibodies were also detected at an early stage. Another 2 patients had a chronic form of autoimmune thyroiditis with early hypothyroidism and with high concentrations of antiTg and antiTPO, but no autoantibodies to the TSH receptor were detected. In the last 2 children, the chronic form of non-autoimmune thyroiditis with initial hypothyroidism was diagnosed. The antiTg, antiTPO and antiTSHr concentrations were within the reference range for these patients. After the diagnosis was determined, the patients were administered L-thyroxine in a daily dose of 0.73 to 2.13 µg L-T4/kg per day.

Methods:
Thyroid hormones and factors were determined in serum using commercially available kits companies Roche Diagnostics, Zentech S.A. and Brahms. Iodine in urine was measured by our laboratory procedure using alkaline melting of urine specimens, followed by a Sandell-Kolthoff reaction in the mineralizate.

Results:
It can be confirmed that the Tg level drops during the successful treatment of hypothyroidism. The decrease of Tg can serve as an indicator of the thyroid's improving state.

Conclusions:
The dynamics of change of the circulating Tg can contribute to an improvement of the laboratory diagnosis of the thyroid and the significance of determining the Tg is broader than its common use as an indicator of the state of the patient with differentiated carcinoma of the thyroid.

Key words:
thyroglobulin, hypothyroidism, laboratory diagnosis of the thyroid


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Labels
Neonatology Paediatrics General practitioner for children and adolescents
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