The association of anti-CCP1 antibodies with disease activity score 28 (DAS-28) in rheumatoid arthritis

BACKGROUND: Rheumatoid arthritis (RA) is one of the most frequent autoimmune diseases in the world which affect about 1% of people. Measurement of the anti-CCP1 antibody titer in these patients is one of the new tests that is available in our country and in the multiple studies has been shown to be more specific than rheumatoid factor in the diagnosis of RA (97%). This test becomes positive in early stage of disease and it has a high predictive value. The aim of our study was to determine the relationship between anti-CCP1 antibody and disease activity score 28 (DAS-28) in patients with rheumatoid arthritis. MATERIALS AND METHODS: A cross-sectional study was performed in 90 patients with RA for evaluating the relation between anti-CCP1 antibody titer and DAS-28, patients were selected by consecutive method; serum samples were collected from patients. Anti-CCP1 antibody was measured by the corresponding enzyme-linked immunosorbent assay. Additionally, erythrocyte sedimentation rates (ESR), rheumatoid factor (RF), DAS-28, visual analog scale (VAS) were determined in patients with RA. Statistical analysis performed with t-test and Pearson's correlations coefficient. RESULTS: Anti-CCP1 level was associated with DAS-28 (P<0.001, r=0.35). The largest linear correlation was between anti-CCP1 antibody levels and VAS; it means that higher titers of anti-CCP1 antibody are associated with more painful joints in our patients. The average of DAS-28 in our positive and negative anti-CCP1 antibody patients was 5.07±1.1 and 3.5±1.5, respectively (P<0.05). CONCLUSION: There was moderate correlation between anti-CCP1 titer and DAS-28.