This test is done to help in diagnosis of rheumatoid arthritis (RA) and to help distinguish RA from other forms of arthritis or other conditions that cause similar symptoms.  Higher levels of RF generally correlate with more severe disease and a poorer prognosis. Positive RF test results may also be seen in 1-5% of healthy people and in some people with conditions such as: Sj�gren syndrome, scleroderma, systemic lupus erythematosus (lupus), sarcoidosis, endocarditis, tuberculosis, syphilis,HIV/AIDS, hepatitis, infectious mononucleosis, cancers such as leukemia and multiple myeloma, parasitic infection, or disease of the liver, lung, or kidney.