Predictors and prognostic stratification for lupus low disease activity state: results from a prospective clinical trial.

OBJECTIVE:To identify predictors for lupus low disease activity state (LLDAS), early-achieved LLDAS and long-term disease activity, and to refine a prognostic stratification tool for use in active SLE patients. METHOD:A total of 245 active SLE patients were enrolled, followed up quarterly from 2014 to 2016. LLDAS-50 was defined as the maintenance of LLDAS for ≥50% of the observed time. LLDAS at 3 months after cohort entry (LLDAS-3mo) was considered an early-achieved LLDAS. Multivariate analysis was performed to identify predictors for LLDAS, early-achieved LLDAS and long-term disease activity. Based on the factors associated with LLDAS, a prognostic stratification tool for LLDAS was established. RESULTS:The 2-year probability of achieving LLDAS was 62.9% (154/245). Multivariate analysis-determined renal involvement, haematological involvement and hypocomplementaemia were negative predictors for achieving LLDAS and LLDAS-50. In multivariate logistic analysis, antiphospholipid antibodies positivity, hypocomplementaemia, renal involvement and haematological involvement were identified as negative predictors for achieving LLDAS-3mo. LLDAS-3mo (P < 0.0001; risk ratio: 47.694; 95% CI: 13.776, 165.127) was a strong predictor for LLDAS-50. The probability of achieving LLDAS, LLDAS-50 and LLDAS-3mo were 88.9% (32/36), 69.4% (25/36) and 41.7% (15/36) in the low-risk group, 65% (65/100), 51.0% (51/100) and 32.0% (32/100) in intermediate-risk group, and 52.8% (57/108), 27.8% (30/108) and 13.0% (14/108) in high-risk group respectively. Significant differences (P < 0.0001) were observed in the LLDAS Kaplan-Meier estimates for the three risk groups based on the identified risk factors. CONCLUSION:Renal involvement, haematological involvement and hypocomplementaemia were negative predictors of LLDAS achievement and maintenance. LLDAS-3mo was a positive predictor for the long-term sustainment of LLDAS.