Biomarker Lens

Common biomarkers

  • Hemoglobin
  • Glucose
  • ALT
  • Apolipoprotein B
  • C-Reactive Protein, Cardiac
  • Ferritin
  • Alb/Creat Ratio, Urine
  • Alkaline Phosphatase
  • FSH
  • T4,Free(Direct)

Biomarkers · Chemical

Rheumatoid Factor

A rheumatoid factor (RF) test checks a sample of your blood for rheumatoid factor, a protein made by the immune system.

Rheumatoid Factor (RF) Test, MedlinePlus, National Library of Medicine

Primary unit
IU/mL
LOINC codes
11572-5
Tests that measure Rheumatoid Factor
Quest Diagnostics 14, Labcorp 9

Ranges

Each lab publishes a reference range for the population groups it tests, usually the middle 95% of results. These intervals describe that population, not an optimal or healthy target. How ranges differ

Quest Diagnostics, Rheumatoid Arthritis Diagnostic Panel 1 17669

PopulationInterval
Rheumatoid Factor<14 IU/mL
CCP Antibody, IgGNot stated
Negative<20
Weak Positive20-39
Moderate/Strong Positive40-59
Strong Positive>59

Quest Diagnostics test catalog, 17669

Quest Diagnostics, Rheumatoid Arthritis Diagnostic Panel 2 91472

PopulationInterval
Rheumatoid Factor<14 IU/mL
CCP Antibody (IgG)Not stated
Negative<20 units
Weak positive20-39 units
Moderate positive40-59 units
Strong positive>59 units
MCV Antibody<20 U/mL

Quest Diagnostics test catalog, 91472

Quest Diagnostics, Sjogren's Panel with Rheumatoid Factor and ANA, IFA with Reflex 90077

PopulationInterval
ANA Screen, IFANegative
ANA TiterNot stated
<1:80Negative
1:80Low antibody level
>1:80Elevated antibody level
Sjögren's Antibody (SS-A)<1.0 Negative AI
Sjögren's Antibody (SS-B)<1.0 Negative AI
Rheumatoid Factor<14 IU/mL

Quest Diagnostics test catalog, 90077

Tests

Check the catalog code, specimen, method and preparation for every test that measures Rheumatoid Factor. Select up to five tests to compare them side by side.

Quest Diagnostics 14 tests

Single-analyte tests

  • Rheumatoid Factor 4418

    Serum · Fasting not stated · Turnaround Set up: Mon-Fri; Report available: 5 days

    Method and collection
    Method
    Immunoturbidimetric
    Reference notes
    <14 IU/mL
    Quest Diagnostics catalog page

Panels that include this biomarker

  • ANA Screen,IFA,with Reflex to Titer and Pattern/Rheumatoid Arthritis Panel1 90071

    2 analytes · Serum · Fasting not stated

    Method and collection
    Method
    Immunoassay (IA) • Immunofluorescence Assay (IFA) • Immunoturbidimetric
    Reference notes
    See individual tests
    Quest Diagnostics catalog page

  • Rheumatoid Arthritis Diagnostic Panel 1 17669

    2 analytes · Serum · Fasting not stated

    Method and collection
    Method
    Immunoturbidimetry • Immunoassay (IA)
    Quest Diagnostics catalog page

  • ANA, IFA, Cascade and Rheumatoid Arthritis Panel 2, with Reflexes 94954

    3 analytes · Serum · Fasting not stated

    Method and collection
    Method
    Enzyme Linked Immunosorbent Assay (ELISA) • Immunofluorescence Assay (IFA) • Immunoturbidimetric
    Collection
    Allow blood to clot (10-15 minutes) at room temperature. Centrifuge and separate from cells.
    Reference notes
    See Laboratory Report
    Quest Diagnostics catalog page

  • Rheumatoid Arthritis Diagnostic Panel 2 91472

    3 analytes · Serum · Fasting not stated

    Method and collection
    Method
    Enzyme Linked Immunosorbent Immunoassay (ELISA) • Immunoturbidimetric Assay
    Quest Diagnostics catalog page

  • Sjogren's Panel with Rheumatoid Factor and ANA, IFA with Reflex 90077

    3 analytes · Serum · Fasting not stated

    Method and collection
    Method
    Immunoassay (IA) • Immunofluorescence Assay (IFA) • Immunoturbidimetric
    Quest Diagnostics catalog page

Labcorp 9 tests

Single-analyte tests

  • Rheumatoid Factor (RF) 006502

    Serum · Fasting not stated · Turnaround Within 1 day

    Method and collection
    Method
    Latex immunoturbidimetry
    Reference notes
    <14.0 IU/mL
    Labcorp catalog page

  • Rheumatoid Factor by Turbidimetry (RDL) 520129

    Serum · Fasting not stated · Turnaround 7 - 14 days

    Method and collection
    Method
    Turbidimetry
    Collection
    Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
    Labcorp catalog page

Panels that include this biomarker

  • Rheumatoid Arthritis (RA) Profile 164065

    2 analytes · Serum · Fasting not stated · Turnaround 2 - 3 days

    Method and collection
    Method
    Latex immunoturbidimetry and enzyme-linked immunosorbent assay (ELISA)
    Labcorp catalog page

  • Rheumatoid Arthritis (RA) Profile with Reflex to SeroNeg RAdx4 520298

    2 analytes · Serum · Fasting not stated · Turnaround 8 - 11 days

    Method and collection
    Method
    Enzyme-linked immunosorbent assay (ELISA); Turbidimetry
    Collection
    Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.
    Labcorp catalog page

  • RheumAssure® 504509

    3 analytes · Serum · Fasting not stated · Turnaround 8 - 12 days

    Method and collection
    Method
    RA Factor: Immunoturbidimetry CCP Antibodies: ELISA 14-3-3 eta protein: ELISA
    Reference notes
    • RA Factor:<14 IU/mL • CCP Antibodies IgG, IgA: Units Negative: <20 Weak positive: 20 - 39 Moderate positive: 40 - 59 Strong positive: >59 • 14-3-3 eta protein: <0.2 ng/mL
    Labcorp catalog page

  • RAdx6 Profile 520304

    5 analytes · Serum · Fasting not stated · Turnaround 7 - 12 days

    Method and collection
    Method
    Enzyme-linked immunosorbent assay (ELISA)
    Collection
    Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.
    Labcorp catalog page

  • Vasculitis Profile (RDL) 520293

    9 analytes · Serum · Fasting not stated · Turnaround 10 days

    Method and collection
    Method
    See individual test components.
    Collection
    Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping. To avoid delays in turnaround time when requesting multiple tests on frozen samples , please submit separate frozen specimens for each test requested.
    Labcorp catalog page

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Sources

Verify these ranges and sources

We compile this page from named laboratory catalogs, guidelines and studies. Labs calculate reference intervals from the people they test, for one assay method and one population group, so an interval describes that population rather than an optimal target.

Interpret your own results with a licensed clinician, or track your lab history and health goals in Aumnivida.

Spotted an error? Email hello@biomarkerlens.com with the page URL and the primary source that corrects the entry.