What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveBoth

LOINC Code 40564-7: Thyroid transcription factor 1 Ag Immune stain Ql (Tiss)

Name: LOINC Code 40564-7: Thyroid transcription factor 1 Ag Immune stain Ql (Tiss)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:27.146Z

40564-7 is a LOINC code used to identify Thyroid transcription factor 1 Ag Immune stain Ql (Tiss) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Thyroid transcription factor 1 Ag. It is commonly used with the system or sample type Tiss.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Thyroid transcription factor 1 Ag. It is commonly used with the system or sample type Tiss.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Both
Method: Immune stain

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Thyroid transcription factor 1 Ag [Presence] in Tissue by Immune stain
Thyroid transcription factor 1 Ag
Antigen; Antigens; Fac; Fact; i; IHC; Imm; Immunohistochemical stain; Immunostain; ImStn; Imun; Imune; NK2 homeobox 1; NKX2-1; Ordinal; PATHOLOGY; Point in time; PR; QL; Qual; Qualitative; Random; Screen; St; Stains; Stn; Tissue; Tissue, unspecified; TTF1; TTF-1

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Thyroid transcription factor 1 Ag Immune stain Ql (Tiss)Thyroid transcription factor 1 Ag [Presence] in Tissue by Immune stainTTF1 Ag Tiss Ql ImStnThyroid transcription factor 1 AgPATHThyroid transcription factor 1 antigen, TissuePrThr

Frequently asked questions

Code details

Code40564-7

SystemLOINC

Display nameThyroid transcription factor 1 Ag Immune stain Ql (Tiss)

DescriptionThyroid transcription factor 1 Ag

Short nameTTF1 Ag Tiss Ql ImStn

ComponentThyroid transcription factor 1 Ag

PropertyPrThr

TimingPt

System (specimen)Tiss

ScaleOrd

MethodImmune stain

ClassPATH

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.15

Last changed2.73

Consumer names

Thyroid transcription factor 1 antigen, Tissue

Part names

Thyroid transcription factor 1 AgPrThrPtTissOrdImmune stainPresence or ThresholdPoint in time (spot)Tissue and Smears

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.