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Rheumatoid Factor (RF) — Unspecified Specimen and Method

Published: August 9, 2026Updated: August 16, 2026

A blood test that measures rheumatoid factor, an antibody sometimes associated with rheumatoid arthritis and other inflammatory conditions.

Quick summary

["A positive rheumatoid factor result can support an inflammatory or autoimmune diagnosis but does not prove rheumatoid arthritis by itself."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
30815-5
Short code
RF Guided BD+PD Endo--W contr Retro
Synonyms
RF Guided BD+PD Endo--W contr Retro
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
rf
CPT
86430
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

Rheumatoid factor (RF) is an antibody that can be detected in blood. The submitted test code does not clearly identify the specimen or laboratory method, so those details should be confirmed with the ordering laboratory.

Why might I need this test?

Your clinician may order this test when you have joint pain, swelling, stiffness, or symptoms suggesting an autoimmune or inflammatory condition. It may also be used alongside other laboratory and clinical findings.

How is the test performed?

A blood sample is usually collected and analyzed in the laboratory. Depending on the laboratory's method, the result may be reported as positive or negative or as a measured concentration.

How do I prepare for the test?

No special preparation is usually required. Follow any instructions from the ordering clinician or laboratory, and tell them if you are pregnant, ill, or recently received certain treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Rheumatoid factor

Frequently asked questions

Does a positive rheumatoid factor result mean I have rheumatoid arthritis?
No. RF can be present in other conditions and in some people without rheumatoid arthritis, so your clinician must interpret it in the context of your overall health.
Can I have rheumatoid arthritis with a negative RF result?
Yes. Some people with rheumatoid arthritis have an undetectable RF result, so additional antibodies, imaging, and clinical findings may be needed.
Is this the same as testing for anti-CCP antibodies?
No. RF and anti-CCP are different antibodies. Your clinician may order both to better evaluate the possibility of rheumatoid arthritis.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy