LOINCActiveObservation

LOINC Code 4694-6: HLA Ag present Nom (Bld/Tiss)

4694-6 is a LOINC code used to identify HLA Ag present Nom (Bld/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 HLA Ag present. It is commonly used with the system or sample type Bld/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 HLA Ag present. It is commonly used with the system or sample type Bld/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: Observation

What it does not mean

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

Key facts

  • HLA Ag present [Identifier]
  • HLA Ag present
  • Blood; HLA ANTIGEN; Human Leukocyte Antigen; Identity or presence; Nominal; Point in time; Random; Tissue; Tissue, unspecified; WB; Whole blood; Whole blood or Tissue

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

HLA Ag present Nom (Bld/Tiss)HLA Ag present [Identifier]HLA Ag presentHLAHLA Ag present, Blood or tissue specimenPridPt

Frequently asked questions

Code details

Code4694-6
SystemLOINC
Display nameHLA Ag present Nom (Bld/Tiss)
DescriptionHLA Ag present
Short nameHLA Ag present
ComponentHLA Ag present
PropertyPrid
TimingPt
System (specimen)Bld/Tiss
ScaleNom
ClassHLA
StatusACTIVE
Order/ObservationObservation

Flags

BillableNo
Valid clinical useNo

Source

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

Consumer names

HLA Ag present, Blood or tissue specimen

Part names

HLA Ag presentPridPtBld/TissNomPresence or IdentityPoint in time (spot)Blood or Tissue

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 4694-6 | HealthAssure