Determinants and protective associations of the lupus low disease activity state in a prospective Chinese cohort.

OBJECTIVE: To investigate the frequency and determinants of achieving the lupus low disease activity state (LLDAS), and the effect of LLDAS attainment on disease flare and damage accrual in a prospective, single-center cohort of Chinese lupus patients. METHODS: Baseline and follow-up data from consecutive patients at the Peking University First Hospital were collected from January 2017 to June 2020. RESULTS: A total of 185 patients were enrolled, with median (range) disease duration at enrolment of 2.3 (0.8-7.7) years, and median follow-up of 2.2 (1.0-2.9) years. By the end of the study, 139 (75.1%) patients had achieved LLDAS at least once; 82 (44.3%) patients achieved LLDAS for ≥ 50% of observations. Multivariable logistic regression analysis showed that 24-h urinary total protein (UTP; per g) (OR = 0.447, 95%CI [0.207-0.968], p = 0.041), serum creatinine (Scr; per 10 µmol/L) (OR = 0.72, 95%CI [0.52-0.99], p = 0.040), and C3 level (per 100 mg/L) (OR = 1.60, 95%CI [1.18-2.17], p = 0.003) at recruitment had independent negative associations with achieving LLDAS for ≥ 50% of observations. Kaplan-Meier analyses showed a significant reduction in flare rate with increased proportion of time in LLDAS. Attainment of LLDAS in at least 50% of observations was an independent protective factor for damage accrual (OR = 0.19, 95%CI [0.04-0.99], p = 0.049). CONCLUSIONS: In this prospective Chinese cohort, LLDAS was an attainable goal in clinical practice. Nephritis-related markers (UTP and Scr) and C3 level at recruitment negatively influenced achievement of LLDAS. LLDAS achievement was significantly protective from flare and damage accrual. KEY POINTS: • Low disease activity status (LLDAS) is an achievable target during SLE treatment in China. Urine protein, serum creatinine, and C3 level at recruitment independently affect LLDAS achievement in this group of Chinese lupus patients. • As a treatment target, LLDAS achievement has a highly protective effect for preventing flare and damage accrual, especially in case of achieving LLDAS for ≥ 50% of observations. • The present results further highlight the practical significance of treat-to-target principle in SLE management (T2T/SLE) and the needs for promoting the application of T2T/SLE in clinical practice as well as exploring the concrete implement strategy.