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 17540-6: R. typhi IgA IF Qn (S)

Name: LOINC Code 17540-6: R. typhi IgA IF Qn (S)
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

17540-6 is a LOINC code used to identify R. typhi IgA IF 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 Rickettsia typhi Ab.IgA. 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 Rickettsia typhi Ab.IgA. 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
Method: IF

What it does not mean

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

Key facts

Rickettsia typhi IgA Ab [Units/volume] in Serum by Immunofluorescence
Rickettsia typhi Ab.IgA
ABS; Aby; ACIF; Antby; Anti; Antibodies; Antibody; Anticomplement Immunofluorescence; Arbitrary concentration; Autoantibodies; Autoantibody; Endemic typhus; FA; Fluorescent antibody; Fluoresent; ID; IFA; Immune fluorescence; Immune globulin A; Immunoflour; Immunofluor; Immunofluorescence; Immunoglobulin A; Infectious Disease; InfectiousDisease; Microbiology; Murine typhus; Point in time; QNT; Quan; Quant; Quantitative; R typhi; Random; Ricket; Rickettsial; Serum; SR; Time Resolved Fluorescence; TRF; Typh; Typhus

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.

Related SNOMED CT concepts

705114005SNOMED CT mapping for R. typhi IgA IF Qn (S) (17540-6)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

R. typhi IgA IF Qn (S)Rickettsia typhi IgA Ab [Units/volume] in Serum by ImmunofluorescenceR typhi IgA Ser IF-aCncRickettsia typhi Ab.IgAMICRORickettsia typhi IgA antibody, BloodACnc

Frequently asked questions

Code details

Code17540-6

SystemLOINC

Display nameR. typhi IgA IF Qn (S)

DescriptionRickettsia typhi Ab.IgA

Short nameR typhi IgA Ser IF-aCnc

ComponentRickettsia typhi Ab.IgA

PropertyACnc

TimingPt

System (specimen)Ser

ScaleQn

MethodIF

ClassMICRO

StatusACTIVE

Order/ObservationBoth

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0l

Last changed2.69

Consumer names

Rickettsia typhi IgA antibody, Blood

Part names

Rickettsia typhi Ab.IgAACncPtSerQnIFRickettsia typhi IgAArbitrary ConcentrationPoint in time (spot)SerumImmunofluorescence (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.