Rheumatoid factor
What is being analysed?
The rheumatoid factor (RF) test is a diagnostic tool used to detect the presence of antibodies in the blood that target healthy tissues, particularly in rheumatoid arthritis.
What does the result signify?
A positive result for RF indicates the presence of antibodies that may attack healthy tissues, leading to inflammation and joint damage characteristic of rheumatoid arthritis. However, it's important to note that RF positivity does not necessarily confirm a diagnosis of rheumatoid arthritis, as it can also be found in other conditions and in some healthy individuals.
Why conduct the analysis?
The analysis is performed to assist in the diagnosis of rheumatoid arthritis, especially when combined with other clinical findings and diagnostic tests. It helps healthcare providers evaluate the likelihood of rheumatoid arthritis and guide treatment decisions.
When to conduct the analysis?
The RF test may be requested when a patient presents with symptoms suggestive of rheumatoid arthritis, such as:
- joint pain;
- swelling;
- stiffness, and;
- fatigue.
What sample is required?
A blood sample is required for the RF test, typically obtained through venipuncture.
Is any prior preparation necessary?
No specific preparation is necessary for the RF test. However, patients should follow any instructions provided by their healthcare provider regarding fasting or medication restrictions, if applicable.
How is it used?
The RF test detects the presence of antibodies in the blood that target healthy tissues. Elevated levels of RF may indicate an autoimmune response, suggesting the presence of rheumatoid arthritis or other autoimmune conditions.
What are the normal values?
Normal RF values are typically defined by the laboratory conducting the analysis. However, in general, RF levels below a certain threshold are considered normal.
What does it mean to have altered values?
Elevated RF levels indicate the presence of antibodies targeting healthy tissues, which may suggest the presence of rheumatoid arthritis or other autoimmune conditions. However, it's important to note that RF positivity can also occur in healthy individuals and other conditions.
Rheumatoid factor values table
Rheumatoid factor levels | Interpretation |
Normal | Below laboratory-defined threshold |
Elevated | Indicates potential autoimmune response, possible rheumatoid arthritis or other autoimmune conditions |
Please note that interpretation of RF test results should be done in conjunction with clinical evaluation by a qualified healthcare professional.