Rheumatoid factor (RF) is an essential component in diagnosing rheumatoid arthritis (RA) and other autoimmune diseases. A positive rheumatoid factor test indicates a high level of rheumatoid factor in the blood, often linked with autoimmune diseases, particularly rheumatoid arthritis. However, elevated RF levels can also be associated with various conditions, including cancer.
The diagnosis of rheumatoid arthritis is categorized into two primary types: seropositive and seronegative. Seropositive, the more common diagnosis among RA patients, signifies the presence of antibodies hypothesized to cause RA symptoms. It’s important to note that rheumatoid factor is not exclusive to RA; it’s found in other autoimmune and non-autoimmune diseases and can be present in up to 4% of healthy young individuals and the elderly.
Rheumatoid factor is an antibody predominantly found in most RA patients. A positive test for rheumatoid factor aids in diagnosing but does not conclusively confirm RA. Many patients with various autoimmune disorders and inflammatory conditions can test positive for rheumatoid factor without having rheumatoid arthritis.
Interestingly, many people with rheumatoid arthritis have little or no rheumatoid factor. If RA symptoms are present but RF test results are normal, additional tests may be necessary for diagnosis. A positive (abnormal) result indicates a higher level of rheumatoid factor in the blood, but this doesn’t always mean rheumatoid arthritis is present. For more detailed information on rheumatoid factor and its role in RA diagnosis, visit RheumatoidArthritis.org, Mayo Clinic, Seropositive RA: Understanding This Type of RA, Medical News Today, NCBI Bookshelf, and MedlinePlus Medical Test.
