High levels of rheumatoid factor (in general, above 20 IU/mL, 1:40, or over the 95th percentile; there is some variation among labs) occur in rheumatoid arthritis (present in 80%) and Sjögren s syndrome (present in 70%). The higher the level of RF the greater the probability of destructive articular disease. It is also found in Epstein-Barr virus or Parvovirus infection and in 5-10% of healthy persons, especially the elderly. There is an association between rheumatoid factor and more persistently active synovitis, more joint damage, greater eventual disability and Arthritis. Other than in rheumatoid arthritis, rheumatoid factor may also be elevated in.. Systemic lupus erythematosus (SLE) Sjögren s syndrome Interstitial pulmonary fibrosis Hepatitis B, Chronic liver disease and chronic hepatitis Essential mixed cryoglobulinaemia Primary biliary cirrhosis Infectious mononucleosis and any chronic viral infection Bacterial endocarditis Leprosy Sarcoidosis Tuberculosis Syphilis Visceral leishmaniasis Malaria Leukemia Dermatomyositis Systemic sclerosis After vaccination/transfusion in normal individuals So positive rhematoid factor not necessarily indicated rhematoid arthritis. Search for other causes also necessary......