AB0223 Prognostic factors for radiographic damage in patients with seronegative rheumatoid arthritis

Background Long since it have been suggested that seronegative rheumatoid arthritis (RA) represents a clinical entity quite distinct from that of seropositive RA. However, analytical studies dedicated to clinical outcomes regarding radiographic progression and risk factors for that are scarece1,2. Objectives The aim of this study is to evaluate radiographic outcome and prognostic factors for radiographic damage in patients with seronegative RA. Methods RA pateints reportedly seronegative for both rheumatoid factor and anti-cyclic citrullinated peptide antibody who were seen at Jeju National University Hospital in South Korea between August 2003 and December 2016, and followed-up at least 2 years were included. Medical records, laboratory and radiographic data was retrospectively analyzed and multivariate analysis was performed to evaluate prognostic factors for radiographic damage in patients with seronegative RA. Results One hundred six patients with seronegative RA were observed and 16 (15.1%) patients demonstrated newly-developed joint damage during follow-up period. Age at diagnosis was 38.9 years and 64 (60.4%) patients were female. Symptom duration at diagnosis was 1.1 years and follow-up duration was 4.4 years. Baseline characteristics including sex, symptom duration, smoking status, number of active joints, acute phase reactant, joint erosion at diagnosis were not significantly different in patients with joint damage compared to those without joint damage. Joint erosion at diagnosis and smoking status were associated with radiographic damage in seronegative RA adjusting age, symptom duration, ESR, CRP values at diagnosis, and follow-up duration, whereas it was not statistically significant (adjusted odds ratio 1.45;p=0.061 and 1.58;p=0.072 respectively). Conclusions Our study demonstrated a rate of joint damage in patients with seronegative RA comparable to recent studies. Joint erosion at diagnosis and smoking status showed tendency to correlate with progression of radiographic damage in patients with seronegative RA. A large comparative study dedicated to this issue in seronegative RA is required. References Ajeganova, S. & Huizinga, T. W. J. Nat. Rev. Rheumatol. 11, 8–9 (2015). A.G. Pratt, J.D. 652 Isaacs/Best Practice & Research Clinical Rheumatology 28 (2014) 651e659. Disclosure of Interest None declared