Characterisation and outcomes of different subsets of low disease activity states in patients with systemic lupus erythematosus.

Objectives: The lupus low disease activity state (LLDAS) allows for certain clinical and/or serological activity of SLE, provided overall disease activity does not exceed predefined cut-offs. This study aimed to evaluate the outcomes of patients who achieved LLDAS with clinical activity, serological activity only or neither clinical nor serological activity.

Methods: Patients with SLE enrolled in a prospective multinational cohort from March 2013 to December 2020 who were in LLDAS at least once were included. Visits that fulfilled both LLDAS and Definition of Remission in SLE (DORIS) criteria were excluded.

Results: 2099 patients were included, with median follow-up of 3.5 (IQR 1.3-5.8) years. At 6150 visits, patients were in LLDAS but not DORIS criteria; of these 1280 (20.8%) had some clinical activity, 3102 (50.4%) visits had serological activity only and 1768 (28.8%) visits had neither clinical nor serological activity. Multivariable regression analysis showed that compared with non-LLDAS, all three subsets of LLDAS had a protective association with flares in the ensuing 6 months and damage accrual in the ensuing 36 months. LLDAS with no clinical or serological activity had a significantly stronger protective association with severe flares in the ensuing 6 months compared with LLDAS with clinical activity (HR 0.47, 95% CI (0.27 to 0.82), p=0.007).

Conclusions: LLDAS without any clinical activity accounted for almost 80% of LLDAS visits. This study confirms that all subsets of LLDAS are associated with reduced flare and damage accrual. However, LLDAS without any clinical or serological activity has the strongest protective association with severe flares.