Rheumatoid Arthritis Diagnostic Test - Quantitative Rheumatoid Factor (RF) Test

The quantitative serum rheumatoid factor test measures the concentration of autoantibodies (usually IgM) that target the Fc portion of immunoglobulin G (IgG). Its presence is associated with rheumatoid arthritis, but it is not entirely specific to the disease. It is an important adjunct, along with clinical examination and other tests such as anti-CCP, in the diagnosis and classification of rheumatoid arthritis.