Rheumatoid Factor (RA Factor) Test

The Rheumatoid Factor (RA Factor) test measures the presence of rheumatoid factor antibodies in the blood. It is primarily used to help diagnose rheumatoid arthritis (RA) and other autoimmune diseases. RA Factor is an autoantibody that mistakenly attacks healthy tissues, leading to joint inflammation, pain, stiffness, and swelling.

A high RA Factor level is commonly seen in rheumatoid arthritis, but it can also be elevated in other autoimmune diseases, such as Sjogren’s syndrome, lupus, and chronic infections. However, some healthy individuals may have a mild elevation without any disease, and some RA patients may have normal RA Factor levels (seronegative RA). This test is usually performed alongside Anti-CCP (Cyclic Citrullinated Peptide) antibodies and inflammatory markers (ESR, CRP) for a more accurate diagnosis.