74795-6
Total thyroxine binding capacity in Serum or Plasma
Active
Term Description
T-uptake in T uptake units. T uptake units bear a rough INVERSE relationship to the other T uptake (See AxSym package insert: http://www.promtest.am/tests/thyroid-diagn/T-Uptake.pdf), but actually measures a different phenomenon (total binding capacity instead of unbound hormone).
Part Description
LP183618-0 Total thyroxine binding capacity
Thyroid hormone uptake ("T-uptake") assays provide information on the number of thyroid hormone binding sites, consisting primarily of thyroid binding globulin, thyroxine binding prealbumin and albumin. Since both T4 and T3 bind to these proteins, different assay formats have used either labeled T3 or T4 (the classic T3 resin uptake uses T3). Various T-uptake assays can differ in the units reported (and even the phenomena being measured), requiring mindfulness when selecting LOINC codes. Being used in the calculation of free T3 and free T4 index (FTI), the T-uptake variants also proliferate into variants of FTI. The classic T-uptake reported as % represents the proportion of labeled thyroid hormone (either T3 or T4) added to a sample that remains unbound (modern assays: use LOINC 74793-1; T3 resin uptake method: 3050-2). T-uptake reported as ratio of patient /control is known as thyroid hormone binding ratio, or THBR or T-uptake ratio (use LOINC 74794-9). T-uptake % and THBR generally are inversely proportional to the number of unoccupied thyroid hormone binding sites present. Alternative assay methods that report T-uptake as "T-uptake units" are described as being directly proportional to the total binding capacity (use LOINC 74795-6).
However, the major rationale for measuring the T-Uptake was to obtain a factor for estimating the free T4 (the biologically relevant fraction). Now that Free T4 measures are widely available, accurate and more economical than measuring a T-uptake AND a TT4 , use of the uptake has been discouraged by most experts. Canada has taken the position of not paying for T-uptake measures.
Source: Regenstrief LOINC
LOINC Names Get Info
- Fully-Specified Name
- Total thyroxine binding capacity:
RelRto: Pt: Ser/Plas: Qn: - Long Common Name
- Total thyroxine binding capacity in Serum or Plasma
- Short Name
- Total TBC SerPl
- Display Name
- Total thyroxine binding capacity [Relative ratio]
- Consumer Name Alpha Get Info
- Total thyroxine binding capacity, Blood
Part Model Get Info
- Component
- Total thyroxine binding capacity
LP183618-0
- Analyte
- Total thyroxine binding capacity
LP183618-0
- Component Numerator
- Total thyroxine binding capacity
LP183618-0
- Component Numerator Core
- Total thyroxine binding capacity
LP183618-0
- Component Numerator Core Suffix
- NULL
- Component Denominator
- NULL
- Component Denominator Core
- NULL
- Component Denominator Core Suffix
- NULL
- Challenge
- NULL
- Adjustment
- NULL
- Count
- NULL
- Property
- RelRto
LP6854-6
- Time
- Pt
LP6960-1
- Time Core
- Pt
LP6960-1
- Time Modifier
- NULL
- System
- Ser/Plas
LP7576-4
- System Core
- Ser/Plas
LP7576-4
- Super System
- NULL
- Scale
- Qn
LP7753-9
- Method
- NULL
Basic Attributes
- Class
- CHEM
- Type
- Laboratory
- First Released
- Version 2.48
- Last Updated
- Version 2.82 (MIN)
- Order vs. Observation
- Both
- Common Test Rank Get Info
- 9226
Language Variants Get Info
| Tag | Language | Translation |
|---|---|---|
| ar-JO | Arabic (Jordan) | القدرة الكلية على ربط هرمون الثيروكسين في المصل أو البلازما |
| cs-CZ | Czech (Czechia) | Tyroxin vazebná kapacita: |
| el-GR | Greek (Greece) | Συνολική ικανότητα δέσμευσης θυροξίνης: Synonyms: CHEM Pt Qn RelRto Θυροξίνη Ορός Ορός/Πλάσμα Πλάσμα Συνολική ικανότητα δέσμευσης θυροξίνης |
| es-ES | Spanish (Spain) | Capacidad total de fijación de tiroxina: Synonyms: Cuantitativo |
| es-MX | Spanish (Mexico) | Capacidad total de unión a tiroxina: |
| fr-FR | French (France) | Thyroxine totale capacité de liaison: |
| it-IT | Italian (Italy) | Capacità di legame totale della tiroxina: Synonyms: Chimica Plasma Punto nel tempo (episodio) Rapporto Relativo Siero Siero o Plasma |
| nl-NL | Dutch (Netherlands) | totale thyroxinebindingscapaciteit: |
| ru-RU | Russian (Russian Federation) | Общая тироксин связывающая способность: Synonyms: Количественный Относительный показатель; |
| tr-TR | Turkish (Turkey) | Total tiroksin bağlama kapasitesi: |
| zh-CN | Chinese (China) | 总甲状腺素结合力: Synonyms: T4; |
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LOINC Copyright
Copyright © Regenstrief Institute, Inc. All Rights Reserved. To the extent included herein, the LOINC table and LOINC codes are copyright © Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. See https://