Version 2.80

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

Fully-Specified Name

Component
Total thyroxine binding capacity
Property
RelRto
Time
Pt
System
Ser/Plas
Scale
Qn
Method

Additional Names

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

Basic Attributes

Class
CHEM
Type
Laboratory
First Released
Version 2.48
Last Updated
Version 2.73 (MIN)
Order vs. Observation
Both
Common Test Rank Get Info
9226

Language Variants Get Info

Tag Language Translation
el-GR Greek (Greece) Συνολική ικανότητα δέσμευσης θυροξίνης:RelRto:Pt:Ορός/Πλάσμα:Qn:
Synonyms: RelRto Θυροξίνη Συνολική ικανότητα δέσμευσης θυροξίνης
es-ES Spanish (Spain) Capacidad total de fijación de tiroxina:Ratio relativo:Punto temporal:Suero o Plasma:Qn:
Synonyms: Cuantitativo
es-MX Spanish (Mexico) Capacidad total de unión a tiroxina:Razón relativa:Punto temporal:Suero o Plasma:Cuantitativo:
fr-FR French (France) Thyroxine totale capacité de liaison:Ratio relatif:Ponctuel:Sérum/Plasma:Numérique:
it-IT Italian (Italy) Capacità di legame totale della tiroxina:RelRto:Pt:Siero/Plasma:Qn:
Synonyms: Chimica Plasma Punto nel tempo (episodio) Rapporto Relativo Siero Siero o Plasma
nl-NL Dutch (Netherlands) totale thyroxinebindingscapaciteit:relatieve verhouding:moment:serum of plasma:kwantitatief:
pt-BR Portuguese (Brazil) Capacidade de ligação da tiroxina total::Pt:Soro/Plas:Qn:
ru-RU Russian (Russian Federation) Общая тироксин связывающая способность:ОтнПок:ТчкВрм:Сыв/Плаз:Колич:
Synonyms: Количественный Относительный показатель;Относительное отношение Плазма Сыворотка Сыворотка или Плазма Точка во времени;Момент
tr-TR Turkish (Turkey) Total tiroksin bağlama kapasitesi:GörOr:Zmlı:Ser/Plaz:Kant:
zh-CN Chinese (China) 总甲状腺素结合力:相对比率:时间点:血清/血浆:定量型:
Synonyms: T4;T-4;四碘甲状腺原氨酸;四碘甲腺原氨酸;左旋四碘甲状腺原氨酸;左旋四碘甲腺原氨酸;左旋甲状腺氨酸;左旋甲状腺素;左旋甲状腺素（Levothyroxine，Levo-thyroxine，L-thyroxine）;甲状腺氨酸 全体数量 全部 共计 化学;化学检验项目;化学检验项目类;化学类;化学试验;非刺激耐受型化学检验项目;非刺激耐受型化学检验项目类;非刺激耐受型化学试验;非刺激耐受型化学试验类 可用数量表示的;定量性;数值型;数量型;连续数值型标尺 总 总和 总数 总甲状腺素结合能力;甲状腺素总结合力;TTBC 总量 总额 时刻;随机;随意;瞬间 来自于不同体系的两种分析物之比;相对比;相对比值 汇总 结合性 结合性的 血清或血浆

Example Units

Unit Source
{T-uptake units} Example UCUM Units

LOINC Terminology Service (API) using HL7® FHIR® Get Info

CodeSystem lookup
https://fhir.loinc.org/CodeSystem/$lookup?system=http://loinc.org&code=74795-6