Inflammation system

Rheumatoid Factor (RF)

RF

An antibody marker associated with rheumatoid arthritis.

What is it

Rheumatoid Factor (RF) — in plain English.

Rheumatoid factor is an autoantibody that targets the body's own immunoglobulins. Elevated levels have been associated with rheumatoid arthritis and certain other conditions.

Why it's measured

What RF can reveal.

RF has been used in clinical evaluation of rheumatoid arthritis, though it is not specific to that condition.

Reference range

Where most laboratories draw the standard line.

Standard laboratory reference

< 14 IU/mL

Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.

What results may indicate

Higher vs. lower RF — at a high level.

Elevated

Has been associated with rheumatoid arthritis and certain other autoimmune conditions in published research.

Lower

Is generally considered favorable.

These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.

When it's measured

When RF is typically run.

Used when joint symptoms suggest a rheumatologic condition.

Related markers

Often measured alongside RF.

Measured in

RF is one of 160 biomarkers in the Apex Panel.

A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.

Explore the Apex Panel
160 biomarkers13 body systemsPhysician-reviewed
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This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.