LOINCActiveBoth

LOINC Code 13634-1: Rheumatoid factor Qn (Syn fld)

13634-1 is a LOINC code used to identify Rheumatoid factor Qn (Syn fld) 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 Synv fld.

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 Rheumatoid factor. It is commonly used with the system or sample type Synv fld.

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

What it does not mean

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

Key facts

  • Rheumatoid factor [Units/volume] in Synovial fluid
  • Rheumatoid factor
  • Arbitrary concentration; Fac; Fact; Joint aspirate; Joint fld; Joint flu; Joint fluid; Point in time; QNT; Quan; Quant; Quantitative; Random; RF; Serology; SF; SNV; Syn; Syn fl; Synov; Synovial fluid

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 Qn (Syn fld)Rheumatoid factor [Units/volume] in Synovial fluidRheumatoid fact Snv-aCncRheumatoid factorSERORheumatoid factor, Synovial fluidACnc

Frequently asked questions

Code details

Code13634-1
SystemLOINC
Display nameRheumatoid factor Qn (Syn fld)
DescriptionRheumatoid factor
Short nameRheumatoid fact Snv-aCnc
ComponentRheumatoid factor
PropertyACnc
TimingPt
System (specimen)Synv fld
ScaleQn
ClassSERO
Example unitsIU/mL
StatusACTIVE
Order/ObservationBoth

Flags

BillableNo
Valid clinical useNo

Source

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

Consumer names

Rheumatoid factor, Synovial fluid

Part names

Rheumatoid factorACncPtSynv fldQnArbitrary ConcentrationPoint in time (spot)Synovial fluid

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 13634-1 | HealthAssure