Abstract

In Behcet’s disease (BD) and Brucellosis, joint involvement is very common and it may share similarities with rheumatoid arthritis (RA). Anti-cyclic citrullinated peptides (CCP) are evaluated as more specific autoantibodies than rheumatoid factor (RF) in RA. The aim of this study is to determine whether anti-CCP antibodies are useful in the differential diagnosis of RA from other arthritis or not. 153 serum samples were used in the study; 34 from RA patients, 26 from brucellar arthritis, 20 from BD with arthritis, 41 from BD without arthritis and 32 from healthy controls. In vitro quantitative, anti-CCP levels were measured by using fluoroenzyme-immunoassay (FEIA) method. Among RA patients, 73.5% were anti-CCP-positive and 70.5% were RF-positive. While there was a statistical difference in the anti-CCP and RF positivity rates between RA and brucellar arthritis patients, BD patients and healthy controls (p = 0.0001), there was no statistical difference between BD patients with arthritis and BD patients without arthritis. Also none of the Brucellar arthritispatients was positive for anti-CCP antibodies, one of them were positive for RF. Our results indicate that anti-CCP antibodies are not associated with brucellar arthritis or BD with joint involvement and since they show high specificity and good sensitivity for RA, they can be evaluated as a better marker than RF especially for the differentiation of RA from other types of arthritis such as BD and brucellar arthritis.

Key words: Rheumatoid arthritis, Behcet's disease, brucellar arthritis, anti-cyclic citrullinated peptide antibody, rheumatoid factor.