LOINCActiveBoth

LOINC Code 17781-6: 21-Hydroxylase Ab Qn (S)

17781-6 is a LOINC code used to identify 21-Hydroxylase Ab Qn (S) 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 21-Hydroxylase Ab. 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 21-Hydroxylase Ab. 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

  • 21-Hydroxylase Ab [Units/volume] in Serum
  • 21-Hydroxylase Ab
  • 21Hydroxylase; 21-Hydroxylase p450c21; 21-OH; ABS; Aby; Antby; Anti; Antibodies; Antibody; Arbitrary concentration; Autoantibodies; Autoantibody; Hydroxyl; Point in time; QNT; Quan; Quant; Quantitative; Random; Serology; Serum; SR; Steroid 21-hydroxylase; Steroid 21-monooxygenase

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

21-Hydroxylase Ab Qn (S)21-Hydroxylase Ab [Units/volume] in Serum21Hydroxylase Ab Ser-aCnc21-Hydroxylase AbSERO21-Hydroxylase antibody, BloodACnc

Frequently asked questions

Code details

Code17781-6
SystemLOINC
Display name21-Hydroxylase Ab Qn (S)
Description21-Hydroxylase Ab
Short name21Hydroxylase Ab Ser-aCnc
Component21-Hydroxylase Ab
PropertyACnc
TimingPt
System (specimen)Ser
ScaleQn
ClassSERO
Example unitsarb U/mL
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

SourceLOINC
Version2.82
Releasemain
First released1.0l
Last changed2.73

Consumer names

21-Hydroxylase antibody, Blood

Part names

21-Hydroxylase AbACncPtSerQnArbitrary 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 17781-6 | HealthAssure