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 91824-3: P. jirovecii Ag IF Ql (Lower resp)

Name: LOINC Code 91824-3: P. jirovecii Ag IF Ql (Lower resp)
Creator: HealthAssure Clinical Team
Published: 2026-05-21T09:00:21.442Z

91824-3 is a LOINC code used to identify P. jirovecii Ag IF Ql (Lower resp) 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 Pneumocystis jirovecii Ag. It is commonly used with the system or sample type Respiratory system specimen.lower.

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 Pneumocystis jirovecii Ag. It is commonly used with the system or sample type Respiratory system specimen.lower.

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: IF

What it does not mean

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

Key facts

Pneumocystis jirovecii Ag [Presence] in Lower respiratory specimen by Immunofluorescence
Pneumocystis jirovecii Ag
ACIF; Anticomplement Immunofluorescence; Antigen; Antigens; Breathing; DFA; FA; Fluorescent antibody; Fluoresent; IFA; Immune fluorescence; Immunoflour; Immunofluor; Immunofluorescence; Low; Lower resp; Lungs; Microbiology; Ordinal; P carinii; P jiroveci; P jirovecii; PCP; Pneumocystis carinii; Point in time; PR; QL; Qual; Qualitative; Random; RS; Screen; Spec; Time Resolved Fluorescence; TRF

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

P. jirovecii Ag IF Ql (Lower resp)Pneumocystis jirovecii Ag [Presence] in Lower respiratory specimen by ImmunofluorescenceP jirovecii Ag Lower resp Ql IFPneumocystis jirovecii AgMICROPneumocystis jirovecii antigen, Lower respiratoryPrThr

Frequently asked questions

Code details

Code91824-3

SystemLOINC

Display nameP. jirovecii Ag IF Ql (Lower resp)

DescriptionPneumocystis jirovecii Ag

Short nameP jirovecii Ag Lower resp Ql IF

ComponentPneumocystis jirovecii Ag

PropertyPrThr

TimingPt

System (specimen)Respiratory system specimen.lower

ScaleOrd

MethodIF

ClassMICRO

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.66

Last changed2.79

Consumer names

Pneumocystis jirovecii antigen, Lower respiratory

Part names

Pneumocystis jirovecii AgPrThrPtRespiratory system specimen.lowerOrdIFPresence or ThresholdPoint in time (spot)Lower respiratory specimenImmunofluorescence (IF)

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.