Interpretations

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. The presence of autoantibodies, such as rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA; tested as anti-cyclic citrullinated peptide [anti-CCP]) can precede clinical manifestation of RA by many years. The 2010 ACR rheumatoid arthritis classification criteria focus on the need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent individuals from reaching the chronic, erosive disease state exemplified in the 1987 RA criteria. It defines definite RA as a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains:

Number and site of involve joints (score range 0 5)
Serologic abnormality (score range 0 3)
Elevated acute-phase response (score range 0 1)
Symptom duration (2 levels; range score 0 1)

Negative: < = 13 IU/mL score = 0
Low Pos: > 13 to 39 IU/mL, score = 2
High Pos: > 40 IU/mL, score = 3