LOINCActiveBoth

LOINC Code 2181-6: Cystinyl aminopeptidase (S) [Catalytic activity/Vol]

2181-6 is a LOINC code used to identify Cystinyl aminopeptidase (S) [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 Cystinyl aminopeptidase. It is commonly used with the system or sample type Ser.

Reviewed by HealthAssure Clinical TeamUpdated 25 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 Cystinyl aminopeptidase. It is commonly used with the system or sample type Ser.

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

What it does not mean

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

Key facts

  • Cystinyl aminopeptidase [Enzymatic activity/volume] in Serum
  • Cystinyl aminopeptidase
  • Amiopep; Catalytic Concentration; Chemistry; Cystine arylamidase; Cystinyl AP; Oxytocinase; Point in time; QNT; Quan; Quant; Quantitative; Random; Serum; SR

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

Cystinyl aminopeptidase (S) [Catalytic activity/Vol]Cystinyl aminopeptidase [Enzymatic activity/volume] in SerumCystinyl AP Ser-cCncCystinyl aminopeptidaseCHEMCystinyl aminopeptidase, BloodCCnc

Frequently asked questions

Code details

Code2181-6
SystemLOINC
Display nameCystinyl aminopeptidase (S) [Catalytic activity/Vol]
DescriptionCystinyl aminopeptidase
Short nameCystinyl AP Ser-cCnc
ComponentCystinyl aminopeptidase
PropertyCCnc
TimingPt
System (specimen)Ser
ScaleQn
ClassCHEM
Example unitsarb U/L
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0
Last changed2.68

Consumer names

Cystinyl aminopeptidase, Blood

Part names

Cystinyl aminopeptidaseCCncPtSerQnCatalytic ConcentrationPoint in time (spot)Serum

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.

LOINC Code 2181-6 | HealthAssure