Extra-articular manifestations of rheumatoid arthritis remain a major challenge: data from a large, multi-centric cohort.

INTRODUCTION: Although Rheumatoid Arthritis (RA) extra-articular manifestations (ExtRA) occurrence has been decreasing over time, they are still a major mortality risk factor for patients. OBJECTIVE: To determine the prevalence of ExtRA in a large cohort, and its association with demographic and clinical variables. METHOD: Cross-sectional and observational study, based on a multi-centric database from a prospective cohort, in which 11 public rheumatology centres enrolled RA patients (1987 ARA or 2010 ACR-EULAR). Data collection began in 08-2015, using a single online electronic medical record. Continuous variables were compared using Mann-Whitney U-test, and Fisher's exact test or chi-square test, as appropriate, were used for categorical variables. The level of significance was set at 5% (p < 0.05). RESULTS: 1115 patients were included: 89% women, age [mean ± SD] 58.2 ± 11.5 years, disease duration 14.5 ± 12.2 years, positive Rheumatoid Factor (RF, n = 1108) in 77%, positive anti-cyclic citrullinated peptide (ACPA, n = 477) in 78%. Regarding ExtRA, 334 occurrences were registered in 261 patients, resulting in an overall prevalence of 23.4% in the cohort. The comparison among ExtRA and Non-ExtRA groups shows significant higher age (p < 0.001), disease duration (p < 0.001), RF high titers (p = 0.018), Clinical Disease Activity index (CDAI) (p < 0.001), Disease Activity Index 28 (DAS 28) (p < 0.001), and Health Assessment Questionnaire (HAQ) (p < 0.001) in ExtRA group. Treatment with Azathioprine (p = 0.002), Etanercept (p = 0.049) Glucocorticoids (GC) ('p = 0.002), and non-steroidal anti-inflammatory drugs (NSAIDs) (p < 0.001) were more frequent in ExtRA group. CONCLUSIONS: ExtRA manifestations still show an expressive occurrence that should not be underestimated. Our findings reinforce that long-term seropositive disease, associated with significant disability and persistent inflammatory activity are the key factors related to ExtRA development.