Antigen Antibody Titration for Serologic Reaction (e.g., Rheumatoid Factor)
This test measures the presence and level of antibodies that may indicate an autoimmune condition, such as rheumatoid arthritis. It involves detecting specific proteins in your blood that react with other proteins.
["This test helps identify potential autoimmune diseases by detecting abnormal antibodies in your blood."]
Key facts at a glance
- LOINC
- 27313-6
- Short code
- ASPNAB
- Synonyms
- A niger Ab Titr Ser ID
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top vacuum tube without anticoagulant
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- immune-diffusion
- CPT
- 86606
- SNOMED
- 33334004
- Specimen volume
- 1-2 mL of serum (minimum 0.5 mL)
- Stability
- Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 200
- Lipemia max
- 100
- Icterus max
- 40
- TAT
- 48–120 hours
- Order
- routine
What This Test Measures
The test looks for rheumatoid factor (RF), a type of antibody that can be found in higher amounts in people with rheumatoid arthritis or other autoimmune diseases. The test checks whether your immune system produces these antibodies, which can bind to parts of your own body’s tissues.
How the Test Works
Blood is drawn and analyzed using an immunoassay method to detect the presence and concentration of rheumatoid factor antibodies. The result helps determine if further evaluation is needed for autoimmune conditions.
Why It’s Done
Doctors may order this test if you have symptoms like joint pain, swelling, or stiffness, or if you have a family history of autoimmune diseases. It can also be used as part of a routine check for certain conditions.
Possible Results and Interpretation
A positive result means your blood contains rheumatoid factor antibodies, which may suggest an autoimmune condition like rheumatoid arthritis. A negative result means no significant antibodies were detected, but other tests may still be needed for diagnosis.
Reference range
Negative: No precipitins detected; Positive: Titer reported as the highest dilution showing a visible precipitin band (e.g., 1:1, 1:2, 1:4, 1:8, 1:16, 1:32). Clinical significance increases with higher titers.N/A
No fasting required. No special patient preparation is necessary for Aspergillus antibody testing. Inform the ordering provider of any recent antifungal therapy, immunosuppressive medications, or known exposure to Aspergillus species, as these factors may influence interpretation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Rheumatoid Factor (RF) Screening/Confirmation
Frequently asked questions
What does a positive rheumatoid factor test mean?
Can a negative rheumatoid factor test rule out rheumatoid arthritis?
How often should I get this test?
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 15, 2026. · Read our editorial policy