What Does Rheumatoid Factor Mean?

Rheumatoid factor is the autoantibody that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG and different RFs can recognize different parts of the IgG-Fc. RF and IgG join to form immune complexes that contribute to the disease process.

What is the normal range for rheumatoid factor?

The normal range of RF is from 0-20 IU/ml. RF above 20 IU/ml is not considered enough to diagnose RA, as there other reasons the RF level may be elevated.

What does it mean when you test positive for rheumatoid factor?

Results. A positive rheumatoid factor test result indicates that a high level of rheumatoid factor was detected in your blood. A higher level of rheumatoid factor in your blood is closely associated with autoimmune disease, particularly rheumatoid arthritis.