This is a positive rheumatoid factor. Rheumatoid factor is a protein that can be found in the blood. It is important to note that this is NOT specific for rheumatoid arthritis. Although, it can be present in RA and can be helpful in making the diagnosis of RA, rheumatoid factor can be present in other conditions as well, such as hepatitis C infection, endocarditis, and gammopathies (paraproteinemias). Your Rheumatologist will take a careful history and complete a physical exam to begin to understand why you have these symptoms and what process to attribute them to.
About Rebecca Manno, MD, MHS
Assistant Professor of Medicine
Johns Hopkins University