LOINCActiveBoth

LOINC Code 9543-0: L. pneumophila 1 Ag RIA Ql (U)

9543-0 is a LOINC code used to identify L. pneumophila 1 Ag RIA Ql (U) 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 Legionella pneumophila 1 Ag. It is commonly used with the system or sample type Urine.

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 Legionella pneumophila 1 Ag. It is commonly used with the system or sample type Urine.

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: RIA

What it does not mean

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

Key facts

  • Legionella pneumophila 1 Ag [Presence] in Urine by Radioimmunoassay (RIA)
  • Legionella pneumophila 1 Ag
  • Antigen; Antigens; i; ID; Infectious Disease; InfectiousDisease; L pneumo; L pneumo1; L pneumonphila; Legion; Legionela; Legionella pneumophila serogroup 1; Microbiology; Ordinal; Philadelphia 1; Pneu; pneum; Pneumophilia; Point in time; PR; QL; Qual; Qualitative; Radioimmunoassay; Random; Screen; UA; UR; Urn

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

L. pneumophila 1 Ag RIA Ql (U)Legionella pneumophila 1 Ag [Presence] in Urine by Radioimmunoassay (RIA)L pneumo1 Ag Ur Ql RIALegionella pneumophila 1 AgMICROLegionella pneumophila 1 antigen, UrinePrThr

Frequently asked questions

Code details

Code9543-0
SystemLOINC
Display nameL. pneumophila 1 Ag RIA Ql (U)
DescriptionLegionella pneumophila 1 Ag
Short nameL pneumo1 Ag Ur Ql RIA
ComponentLegionella pneumophila 1 Ag
PropertyPrThr
TimingPt
System (specimen)Urine
ScaleOrd
MethodRIA
ClassMICRO
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

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

Consumer names

Legionella pneumophila 1 antigen, Urine

Part names

Legionella pneumophila 1 AgPrThrPtUrineOrdRIAPresence or ThresholdPoint in time (spot)Radioimmunoassay (RIA)

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 9543-0 | HealthAssure