FRI0021 Predictors of rheumatoid arthritis development in patients with early undifferentiated arthritis: a 2-years follow-up study
Authors: J. Molina Collada, M.G.G. Álvarez, V. Navarro-Compán, L. Nuño Nuño, A. Villalba, D. Peiteado, P. Bogas, A. Balsa
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Early treatment of rheumatoid arthritis (RA) improves longterm outcomes<sup>(1)</sup>. However, at the beginning of the disease, some patients with RA fall within undifferentiated arthritis (UA) patients. Several studies have shown that almost half of patients with UA may experience spontaneous remission<sup>(2)</sup>. So, in order to prevent overtreatment and poor outcomes, the identification of predictors of RA development is desirable. <h3>Objectives</h3> To determine the frequency of patients with UA evolving into RA after 2 years of follow-up and the factors contributing to predict this outcome. <h3>Methods</h3> A prospective analysis of an early arthritis cohort of 1377 patients from 1993 to 2017 was undertaken. For this study, 2 years follow-up data of patients who presented with UA were analysed. A detailed baseline assessment was completed including clinical features, physical examination and laboratory tests. Patients were stratified in two groups based on progression to RA (according to physician's diagnosis) or to another disease (non-RA). First, differences between groups were tested using chi-squared and Student-t tests in the univariate analysis. Second, multivariate logistic regression models were employed to investigate the association between possible predictive factors and RA development. <h3>Results</h3> A total of 471 UA patients were included for analysis. Mean age was 48.7±17.5 years, 352 (74.9%) were females, and mean symptoms duration was 13.9±13.9 weeks. After 2 years of follow-up, 93 (19.7%) of UA patients evolved into RA. Meanwhile, 175 (37.2%) remained undifferentiated and 203 (43.1%) developed into other musculoskeletal diseases. In the univariate analysis, the presence of rheumatoid factor (RF) and anti-citrullinated peptides antibodies (ACPA), tender and swollen joint count, duration of morning stiffness, smoking, symmetry and ESR values were significantly associated with RA development. In the multivariate analysis, RF (OR=5,899; 95% CI 1,795–19,382), ACPA (OR=123,238; 95% CI 29,353–517,410) and swollen joint count (OR=1,233; 95% CI 1,048–1,450), remained significantly associated with RA development (table 1). <h3>Conclusions</h3> Approximately, 1 out of 5 patients with UA evolves into RA after 2 years of follow-up. Swollen joint count, and the presence of rheumatoid factor (RF) and anti-citrullinated peptides antibodies (ACPA) are independent predictors for the development of RA, supporting the early DMARDs initiation in such patients. <h3>References</h3> [1] Lard LR, Visser H, Speyer I, vander Horst-Bruinsma IE, Zwind- erman AH, Breedveld FC, et al. Early versus delayed treatment in patients with recent-onset rheumatoid arthritis: comparison of two cohorts who received different treatment strategies. Am J Med2001;111:446–51. [2] Olivieri I, Sarzi-Puttini P, Bugatti S, Atzeni F, d'Angelo S, Caporali R. Early treatment in early undifferentiated arthritis. Autoimmun Rev2012;11:589–92. <h3>Disclosure of Interest</h3> None declared