Validation of a novel definition of low disease activity state in systemic lupus erythematosus

Abstract

Background and aims While a 'Treat-to-target' principle is widely advocated in management of systemic lupus erythematosus (SLE), there is currently no internationally agreed definition of low disease activity in lupus. In 2015, the Asia-Pacific Lupus Collaboration presented a novel consensus definition of a safe state in lupus, the 'Lupus Low Disease Activity State' (LLDAS). (http://dx.doi.org/10.1136/annrheumdis-2015-207726) Methods This was a prospective study to determine whether LLDAS predicted lower flare-ups, damage and mortality. 339 SLE patients were recruited and followed for 30 months. Multivariable binomial regression was used to determine factors associated with LLDAS and Cox proportional hazard model to determine whether prior higher% of days in LLDAS would be associated with lower future flare-ups. Results Mean patient age was 48.1 years and mean disease duration 19.6 years. Female to male ratio=16 to 1. 79 flareups were documented. 92.6% of patients had ever achieved LLDAS during the study period and 62.1% of patient-days were in LLDAS. No major demographic or prior disease presentations were found to be associated with the attainment of LLDAS. Patients with prior higher percentage of days in LLDAS had lower hazard of lupus flare-ups (HR=0.420, p=0.015) after adjustment for gender and age. The numbers of patient damage and death were insufficient for analysis. Conclusions LLDAS is an independent construct achievable by most patients of different history or background. Our preliminary study shows LLDAS can predict the risk of future flareups though further studies are needed to determine whether it is associated less lupus-related damage and lower mortality.