Rheumatoid factor is currently tested by blood draw.
Rheumatoid factor is a relatively common autoantibody, mainly found in the serum and joints of patients with rheumatoid arthritis, and the concentration of rheumatoid factor is mainly detected by blood sampling.
The normal reference value for rheumatoid factor is less than 20 U/ml, and elevated levels are common in various autoimmune diseases, such as rheumatoid arthritis, polymyositis, scleroderma, desiccation syndrome, systemic lupus erythematosus, and so on.
It is also elevated in certain infectious diseases such as infectious mononucleosis, tuberculosis, and infective endocarditis, and can also be seen in the elderly.
Patients with positive rheumatoid factor are advised to go to the rheumatology and immunology departments of regular hospitals for detailed consultation.