Rheumatoid Factor — Latex Agglutination, Qualitative
A qualitative test that checks a blood sample for rheumatoid factor antibodies using latex agglutination.
["A positive result can support the evaluation of rheumatoid arthritis, but it must be interpreted with your symptoms and other tests."]
Key facts at a glance
- LOINC
- 82602-4
- Short code
- Deprecated Latex (rHev b) 10 IgE RAST Ql
- Synonyms
- Deprecated Latex (rHev b) 10 IgE RAST Ql
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- 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?
This test looks for rheumatoid factor, an antibody that can attack the body's own tissues, especially joints. It uses a latex agglutination method to provide a qualitative result.
Why might I need this test?
Rheumatoid factor testing may be ordered when joint pain, swelling, morning stiffness, or other symptoms suggest an inflammatory condition. It is often evaluated alongside other laboratory and clinical findings.
How is the test performed?
A laboratory combines the patient's specimen, commonly blood serum, with a latex reagent. If rheumatoid factor is present, visible clumping called agglutination may occur; the result is reported as positive or negative.
How do I prepare for the test?
This test usually requires no special preparation or fasting. Follow any instructions from your healthcare professional and tell the laboratory if you have recently received treatments that could affect the result.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result may occur with rheumatoid arthritis, but it can also be associated with certain infections, other autoimmune conditions, or aging. A negative result does not completely exclude rheumatoid arthritis, so the result should be interpreted with symptoms, examination findings, and other tests.
Short name
Rheumatoid factor test
Frequently asked questions
Does a positive result mean I have rheumatoid arthritis?
Is this the same as an anti-CCP test?
Does the qualitative result provide a measured concentration?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy