Mouterde G, et al. - Researchers sought to delineate the disease course of patients with early arthritis without rheumatoid factor (RF) as well as anti-citrullinated protein auto-antibodies (ACPA) in an inception cohort. In addition, baseline predictors of fulfilling 2010 American College of Rheumatology/European League Against Rheumatism criteria for rheumatoid arthritis (RA) for these patients within 3 years were determined. From the multicenter ESPOIR (Etude et Suivi des POlyarthrites Indifferenciées Récentes) cohort, patients were compared at baseline and 3 years by whether they were negative for RF and ACPA (“seronegative”) or positive for RF and/or ACPA (“seropositive”). Among 354 seronegative patients, RA classification was fulfilled by 224/340 with available data (65.9%) at baseline and 189/233 (81.1%) at 3 years. Observations revealed less active disease at baseline and less radiographic progression during follow-up among “seronegative” patients vs “seropositive” patients. A classification of RA is likely with inflammatory pain, symmetric involvement of numerous small joints and erosive disease.