82368-2

LOINC code 82368-2 identifies "Thyroid secretory capacity [Moles/time] in Serum or Plasma by Calculated.SPINA". Thyroid secretory capacity (also called thyroid output or GT) is the maximum secretion rate of the thyroid gland under stimulated conditions. The structure parameter inference approach (SPINA) uses Michaelis-Menten functions and pharmakokinetic data to estimate GT under conditions of substrate saturation. One calculation is based on peripheral TSH, free T4, thyroid binding globulin and thyroid binding prealbumin values, and an alternate calculation uses peripheral TSH and total T4. GT calculated using the SPINA approach is also known as SPINA-GT. SPINA-GT may be useful in diagnosing secondary or tertiary thyroid conditions and has also been shown to be able to clearly differentiate between euthyroidism and functional thyroid disorders of primary origin. [PMID: 27375554] Peripheral deiodinase activity by SPINA, called SPINA-GD, is a related result [LOINC: 82367-4].

This code measures Thyroid secretory capacity in Ser/Plas. It belongs to the CHEM class in the LOINC classification.

LOINC (Logical Observation Identifiers Names and Codes) is a universal standard for identifying laboratory and clinical observations. It is maintained by the Regenstrief Institute and used worldwide for health data exchange.