Erosive arthritis and anti-cyclic citrullinated peptide antibodies in systemic sclerosis

Background: The frequency and characteristics of erosive arthritis in systemic sclerosis (SSc) remains unclear. The aim of the study was to determine the prevalence and characteristics of erosive arthritis and to define the role of anti-CCP antibodies in the differential diagnosis of joint involvement in SSc. Methods: One hundred and fifty patients who met the 1980 American College of Rheumatology (ACR) criteria and/or Leroy and Medsger criteria for SSc were assessed. Results: Among the 150 SSc patients, 139 were women. Their median age was 45.12 ± 13.59 years and disease duration ( first non-Raynaud symptom) of 9.7 years. Of these patients, 5 patients were classified as having limited SSc, 103 as limited cutaneous SSc and 42 as diffuse cutaneous SSc. Joint involvement was characterized as arthralgia in 95 (63%) patients, arthritis in 60 (40%) patients, erosive arthritis in 21 (14%) and systemic sclerosis (SSc)-rheumatoid arthritis (RA) overlap syndrome in 7 patients. The prevalence of diffuse cutaneous involvement (50%) (P = 0.01), digital ulcers (81%) (P = 0.009), interstitial lung disease (81%) (P = 0.009) and anti-topoisomerase I antibodies (P = 0.01) was higher in patients with erosive arthritis. Anti-CCP antibodies were found in 14 of the 150 (9.4%) cases. A statistically significant association between the presence of anti-CCP antibodies and the presence of arthritis (P = 0.01), erosive arthritis (P = 0.01) and SSc-RA overlap syndrome (P < 0.05) was noted. High titers of anti-CCP antibodies were found in patients with SSc-RA overlap syndrome. Conclusion: Erosive arthritis is not rare in SSc, and it might be a marker of severe disease. Anti-CCP antibodies can be present in patients with SSc, and high titers of anti-CCP antibodies may be indicative of SSc-RA overlap syndrome