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 27811-9: Antithrombin actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]

Name: LOINC Code 27811-9: Antithrombin actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:14.572Z

27811-9 is a LOINC code used to identify Antithrombin actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol] 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 Antithrombin actual/Normal. It is commonly used with the system or sample type PPP.

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 Antithrombin actual/Normal. It is commonly used with the system or sample type PPP.

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: Chromo

What it does not mean

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

Key facts

Antithrombin actual/normal in Platelet poor plasma by Chromogenic method
Antithrombin actual/Normal
Act/Nor; Anti thrombin; Antithrm; Antithrombin III; Antithrombn; AT; AT III; ATIII; Chromogenic assay; COAGULATION; Control; ENZY; Enzymatic assay; Hematology; Heme; Heparin cofactor I; Plas; Platelet poor plasma; Point in time; QNT; Quan; Quant; Quantitative; Random; RlCCnc; Thrombin inhibitor I; UniversalLabOrders

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

Antithrombin actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]Antithrombin actual/normal in Platelet poor plasma by Chromogenic methodAT III Act/Nor PPP ChroAntithrombin actual/NormalCOAGAntithrombin actual/normal, BloodRelCCnc

Frequently asked questions

Code details

Code27811-9

SystemLOINC

Display nameAntithrombin actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]

DescriptionAntithrombin actual/Normal

Short nameAT III Act/Nor PPP Chro

ComponentAntithrombin actual/Normal

PropertyRelCCnc

TimingPt

System (specimen)PPP

ScaleQn

MethodChromo

ClassCOAG

Example units%

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.00

Last changed2.73

Consumer names

Antithrombin actual/normal, Blood

Part names

Antithrombin actual/NormalRelCCncPtPPPQnChromoRelative catalytic concentrationPoint in time (spot)Platelet poor plasmaChromogenic (Enzyme)

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.