Rheumatoid Factor antibody
Principal name
Rheumatoid Factor antibody
Available reactivities
Available hosts
Available applications
Enzyme Immunoassay (E), Western blot / Immunoblot (WB), Radioimmunoassay (R)
Background of Rheumatoid Factor antibody
Rheumatoid factor (RF) is the autoantibody that is most relevant in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG. RF and IgG join to form immune complexes that contribute to the disease process. Rheumatoid factor can also be a cryoglobulin (antibody that precipitates on cooling of a blood sample); it can be either type 2 (monoclonal IgM to polyclonal IgG) or type 3 (polyclonal IgM to polyclonal IgG) cryoglobulin.
RF is often evaluated in patients suspected of having any form of arthritis even though positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis. The presence of rheumatoid factor in serum can also indicate the occurrence of suspected autoimmune activity unrelated to rheumatoid arthritis, such as that associated with tissue or organ rejection. In such instances, RF may serve as one of several serological markers for autoimmunity.