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 27818-4: Protein C actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]

Name: LOINC Code 27818-4: Protein C actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:14.572Z

27818-4 is a LOINC code used to identify Protein C 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 Protein C 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 Protein C 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

Protein C actual/normal in Platelet poor plasma by Chromogenic method
Protein C actual/Normal
Act/Nor; Autoprothrombin II-a; Chromogenic assay; COAGULATION; Control; ENZY; Enzymatic assay; Hematology; Heme; PC; Plas; Platelet poor plasma; Point in time; PR; Prot; Prot C; QNT; Quan; Quant; Quantitative; Random; RlCCnc; 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

Protein C actual/normal Chromogenic method (PPP) [Rel catalytic activity/Vol]Protein C actual/normal in Platelet poor plasma by Chromogenic methodProt C Act/Nor PPP ChroProtein C actual/NormalCOAGProtein C actual/normal, BloodRelCCnc

Frequently asked questions

Code details

Code27818-4

SystemLOINC

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

DescriptionProtein C actual/Normal

Short nameProt C Act/Nor PPP Chro

ComponentProtein C 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

Protein C actual/normal, Blood

Part names

Protein C 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.