Objective. The aim of this study was to examine whether the presence of anti-ribonucleoprotein (anti-RNP) antibodies at diagnosis is associated with systemic lupus erythematosus (SLE) flares in newly diagnosed patients during the first year of follow-up. Methods. The medical records of 71 newly diagnosed SLE patients without other concomitant autoimmune disease, serious infection, or malignancy were reviewed retrospectively. SLE flares were defined according to the SLE Disease Activity Index 2000. Patients were divided into 2 groups according to the presence or absence of anti-RNP, and variables were compared between the groups. Results. During the first year of follow-up, SLE patients with anti-RNP at diagnosis more frequently presented with mucosal ulcers (p=0.003), rash (p=0.001), and arthritis (p=0.007), compared to those without anti-RNP. The SLE flare incidence was remarkably higher in patients with anti-RNP than in those without anti-RNP (62.5% vs. 23.1%, p=0.001). SLE patients with anti-RNP at diagnosis had a significantly higher risk of ever experiencing a SLE flare during the first year of follow-up, compared to those without anti-RNP (odds ratio=8.250). Conclusion. In conclusion, SLE patients with anti-RNP at diagnosis were more than 8-fold more likely to experience an SLE flare during the first year of follow-up. (J Rheum Dis 2016;23:154- 160)

Keywords: Anti-ribonucleoprotein, Flare, Systemic lupus erythematosus, Systemic lupus erythematosus disease activity index