The clinical significance of antibody determination to cyclic citrullinated peptides in systemic sclerosis

Introduction. Anti-citrullinated peptides antibodies (ACPA) are present in 80% of sera of rheumatoid arthritis (RA) patients with high specificity for diagnosis and prediction for the development of early erosive arthritis. A few studies have reported a low frequency ACPA in systemic sclerosis (SSc) patients with the presence of arthritis. Objective. The aim of our study was to determine the frequency of ACPA in systemic sclerosis (SSc) patients, their correlation with clinical manifestations and radiographic features. Methods. The study included 82 patients with SSc, mean age 54.4 years, 59 with the limited (lSSc) and 23 with the diffuse (dSSc) form of the disease. The control group included 28 healthy age and sex matched subjects. ACPA and rheumatoid factor (RF) were determined in all SSc patients and healthy subjects in whom standard radiography of hands and wrists was also done. Results. The presence of ACPA was detected in 11 (13.4%) of SSc patients. Their level was not increased in any of the controls. Positive RF was found in 15.9% of SSc patients. Arthritis was present in 17.1%, as well as marginal bone erosions. There was a statistically significant association between positive ACPA and arthritis (p<0.0001) and positive ACPA and marginal bone erosions (p=0.0002). Conclusion. The research confirmed the correlation between ACPA with clinical signs of arthritis and radiographic damage of hand joints. ACPA is a useful diagnostic marker in the identification of SSc patients with arthritis and anatomic bone damage enabling the use of adequate therapy in order to prevent joint damage and poor quality of life