Limbic 365Rheumatoid Factor (RF) test is a blood test that measures the level of antibodies that are produced by the immune system in response to an antigen present in the body. The antigen that triggers RF production is the Fc portion of IgG, which is a type of antibody present in the blood. RF test is commonly used as an aid in the diagnosis of rheumatoid arthritis (RA), an autoimmune disease that causes inflammation in the joints, but it can also be present in other autoimmune and infectious diseases.
What is a Rheumatoid Factor (RF) Test?
RF test is a blood test that measures the level of antibodies that are produced by the immune system in response to an antigen present in the body.
Why is a Rheumatoid Factor (RF) Test ordered?
RF test is commonly used as an aid in the diagnosis of rheumatoid arthritis (RA), an autoimmune disease that causes inflammation in the joints, but it can also be present in other autoimmune and infectious diseases.
How is a Rheumatoid Factor (RF) Test performed?
A Rheumatoid Factor (RF) Test is performed by collecting a blood sample from a vein in your arm. The sample is sent to a laboratory for analysis.
What are the normal values for Rheumatoid Factor (RF) Test?
The normal values for Rheumatoid Factor (RF) Test are as follows: Less than 14 IU/mL
Note: Different laboratories may have slightly different reference ranges, so it is always best to consult with your healthcare provider about your test results.
What factors can affect the accuracy of Rheumatoid Factor (RF) Test?
Several factors can affect the accuracy of RF test, including age, gender, medications, and other health conditions. For example, RF levels tend to increase with age and are higher in women than in men. Medications such as methotrexate and biologic agents used in the treatment of RA can also affect RF levels.
Interpreting Rheumatoid Factor (RF) Test Results
RF test results are reported in international units per milliliter (IU/mL). As mentioned earlier, the normal values for RF test are less than 14 IU/mL. RF levels above this threshold are considered positive and may indicate the presence of RA or other autoimmune diseases. However, a positive RF test does not always mean that a person has RA or another autoimmune disease, as RF can also be present in healthy individuals and in people with other conditions.
On the other hand, a negative RF test does not necessarily rule out the possibility of RA or other autoimmune diseases, as some people with these conditions may not have detectable levels of RF. Therefore, RF test is often used in conjunction with other tests and clinical evaluations to aid in the diagnosis of RA and other autoimmune diseases.
