Thyroid disease examination

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Indicators of Thyroid Dysfunction[edit | edit source]

Control of thyroid hormone secretion

Serum TSH[edit | edit source]

  • Its concentration is inversely proportional to the concentration of T4,
    • assuming normal function of the hypothalamo-pituitary axis reflects the level of T4,
  • significantly increased: primary hypothyroidism,
  • sometimes a modified version is produced - it is also possible to find out
  • method of first choice when primary hypothyroidism or hyperthyroidism is suspected,
  • monitoring T4 replacement therapy,
  • is examined in hypercholesterolemia and hyperprolactinemia.

Functional test with TRH[edit | edit source]

  • Reflects TSH secretion,
  • in central hypothyroidism, in TSH-producing tumors.

Total thyroxine (TT4) and free (FT4) in serum[edit | edit source]

  • Indicators of current secretion,
  • FT4 indicates the availability of the hormone to the tissue,
  • free thyroxine index - FTI.
  • Priority in the treatment of hyperthyroidism, TSH secretion can still be suppressed in the long term.

Serum total (TT3) and free (FT3) triiodothyronine[edit | edit source]

  • High levels of T3 during thyroxine treatment – ​​autonomous hyperactivity of the gland,
  • indication – examination of hyperthyroidism, severity of primary hypothyroidism, differential diagnosis of low TSH values.

Reverse T3 (RT3)[edit | edit source]

  • Indirect indicator of conversion of T4 to T3,
  • investigation of unknown causes of low TT3 or TT4.

Serum Thyroglobulin (TG)[edit | edit source]

  • Indicator of TG release from an active, inflammatory or tumor gland,
  • follow-up of patients after thyroidectomy for differentiated ca as a tumor marker - diagnosis of relapse (rising TG).

α-subunit of hCG[edit | edit source]

  • In general, they detect the formation of molecules with this subunit - also TSH.

Calcitonin, serum thyrocalcitonin[edit | edit source]

  • Indicator of secretory activity of C-cells thyroid glands,
  • in the diagnosis of medullary tumors.

Thyroid hormone transport disorders[edit | edit source]

Thyroxine binding globulin (TBG) in serum[edit | edit source]

  • Quantitatively the most significant carrier,
  • high values: genetically, during pregnancy, with contraception,
  • low concentrations: malnutrition, malabsorption, hepatic synthesis disorders,
  • we investigate T3 and T4 values, which do not correlate with the clinical condition.

Prealbumin, transthyretin in serum[edit | edit source]

  • The second most important transmitter.

Binding capacity of transport proteins, T-uptake[edit | edit source]

  • Meaning and indications as for TBG, we saturate the serum sample with a known concentration of T3 and determine the unbound fraction.

Indicators of autoimmune thyroid diseases[edit | edit source]

Antibodies against thyroperoxidase (Thyreoperoxidase Antibodies, TPOAb)[edit | edit source]

  • Previously described as antimicrosomal,
  • reveal the presence of an autoimmune process, a possible risk of dysfunction,
  • indication: goiter of unknown etiology, differential diagnosis of hyperthyroidism,
  • risk screening after birth.

Thyroglobulin antibodies[edit | edit source]

  • They reveal the autoimmune process, can explain incorrect results of TGB determination,
  • monitoring of differentiated carcinomas of the thyroid gland.

Antibodies against TSH receptors[edit | edit source]

  • They can either stimulate or inhibit,
  • risk of developing Graves disease, risk of endocrine ophthalmopathy,
  • differential diagnosis of hyperthyroidism.

Links[edit | edit source]

Related Articles[edit | edit source]

Used literature[edit | edit source]

  • SCHNEIDERKA, Petr, et al. Kapitoly z klinické biochemie. 2. edition. Praha : Karolinum, 2004. ISBN 80-246-0678-X.