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.

LOINC

LOINC Code 13191-2: Rheumatoid factor Qn

Name: LOINC Code 13191-2: Rheumatoid factor Qn
Creator: HealthAssure Clinical Team
Published: 2026-05-21T11:17:23.609Z

13191-2 is a LOINC code used to identify Rheumatoid factor Qn 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 Rheumatoid factor. It is commonly used with the system or sample type Ser/Plas.

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 Rheumatoid factor. It is commonly used with the system or sample type Ser/Plas.

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: DEPRECATED

What it does not mean

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

Key facts

Deprecated Rheumatoid factor [Units/volume] in Serum
Rheumatoid factor
Arbitrary concentration; Fac; Fact; Pl; Plasma; Plsm; Point in time; QNT; Quan; Quant; Quantitative; Random; RF; Serology; SerP; SerPl; SerPlas; Serum; Serum or plasma; SR

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

Rheumatoid factor QnDeprecated Rheumatoid factor [Units/volume] in SerumDeprecated Rheumatoid fact SerPl-aCncRheumatoid factorSERORheumatoid factor, BloodACnc

Frequently asked questions

Code details

Code13191-2

SystemLOINC

Display nameRheumatoid factor Qn

DescriptionRheumatoid factor

Short nameDeprecated Rheumatoid fact SerPl-aCnc

ComponentRheumatoid factor

PropertyACnc

TimingPt

System (specimen)Ser/Plas

ScaleQn

ClassSERO

Example unitsIU/L

StatusDEPRECATED

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released1.0j-a

Last changed2.36

Consumer names

Rheumatoid factor, Blood

Part names

Rheumatoid factorACncPtSer/PlasQnArbitrary ConcentrationPoint in time (spot)Serum or Plasma

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.