Predictors of flare in SLE patients fulfilling lupus low disease activity state: a cohort study of 292 patients with 36-month follow-up

Objectives The treatment target in SLE should be maintained stable by preventing flares. The objectives were to identify predictors of flare in patients attaining lupus low disease activity state (LLDAS), and to assess whether remission with no glucocorticoids is associated with lower risk of flares. Methods This was a cohort study of SLE patients followed in a referral centre over 3 years. Baseline was the first visit where each patient attained LLDAS. Flares up to 36 months' follow-up were identified by three instruments: revised Safety of Estrogen in Lupus Erythematosus National Assessment (SELENA) Flare Index (r-SFI), SLEDAI-2000 (SLEDAI-2K) and SLE Disease Activity Score (SLE-DAS). Demographic, clinical and laboratory parameters at baseline were evaluated as predictors of flare, with distinct models for each flare instrument, using survival analysis with univariate followed by multivariate Cox regression. Hazard ratios (HR) were determined with 95% CI. Results A total of 292 patients fulfilling LLDAS were included. Over follow-up, 28.4%, 24.7% and 13.4% of the patients developed one or more flare, according to r-SFI, SLE-DAS and SLEDAI-2K definitions, respectively. After multivariate analysis, the predictors of SLE-DAS flares were presence of anti-U1-ribonucleoprotein (anti-U1RNP) (HR = 2.16, 95% CI 1.30, 3.59), SLE-DAS score at baseline (HR = 1.27, 95% CI 1.04, 1.54) and immunosuppressants (HR = 2.43, 95% CI 1.43, 4.09). These predictors were equally significant for r-SFI and SLEDAI-2K flares. Remitted patients with no glucocorticoids presented a lower risk of SLE-DAS flares (HR = 0.60, 95% CI 0.37, 0.98). Conclusion In patients with LLDAS, anti-U1RNP, disease activity scored by SLE-DAS and SLE requiring maintenance immunosuppressants predict higher risk of flare. Remission with no glucocorticoids is associated with lower risk of flares.