Role of anti cyclic citrullinated peptide antibodies in erosive disease in patients with rheumatoid arthritis

Background & objectives: Antibodies to cyclic citrullinated peptide (CCP) are a recently described marker in rheumatoid arthritis (RA), which are said to connote aggressive disease. No data on these antibodies are available from India. We undertook this study to evaluate the role of second generation anti CCP antibodies (anti CCP-2) in predicting erosive disease in Indian patients with rheumatoid arthritis and to define their role in seronegative RA. Methods: A total of 211 patients with established RA were evaluated in this cross-sectional study for radiographic erosions. A high percentage of seronegative RA patients (40%) were included to assess the role of anti CCP-2 antibodies in this subgroup. Radiographic damage was quantified using modified Sharp score. Apart from anti CCP-2 antibodies, other factors evaluated for their ability to predict erosions included rheumatoid factor (RF) positivity, disease duration, and disease modifying anti rheumatic drugs (DMARD) naive period. Results: Anti CCP-2 antibodies were seen in 80 per cent patients with RA. Predictors of erosive disease included anti CCP-2 antibody positivity and DMARD naive period. Patients positive for both RF and anti CCP-2 antibodies had a higher prevalence of erosions as compared to, patients positive for only one antibody or negative for both. In seronegative RA (RF absent), anti CCP-2 antibodies were seen in over 50 per cent patients and were associated with a higher incidence of erosive disease. Interpretation & conclusion: Our finding showed that anti CCP-2 antibodies were present in 80 per cent patients with established RA. These have an independent role in predicting erosive disease, especially in the seronegative subgroup.