Prevalence and outcomes of a pilot definition of severe refractory systemic lupus erythematosus: observations from a multinational Asia-Pacific cohort

Emerging therapies have the potential to be used in patients with severe refractory systemic lupus erythematosus (srSLE), but no agreed definition of srSLE exists. We evaluated a pilot srSLE definition to assess whether a set of disease activity and treatment thresholds could identify patients with poor outcomes. Data from a 13-country longitudinal SLE cohort, collected prospectively between 2013 and 2020 were analysed. srSLE was defined if a patient was in high disease activity (SLEDAI-2K ≥ 10) despite combination use of at least glucocorticoids (GC) and immunosuppressants (IS) at both the index and preceding visit. Synchronised to the index srSLE visit, we assessed disease activity, medication use and treat-to-target (T2T) endpoint attainment over 12 months (m). Of 3,744 patients studied, 578 (14%) had srSLE, in 1,810 visits. The median [IQR] SLEDAI-2K at the srSLE index visit was 12 [10, 14], which decreased to 6 [4, 10] at 6m and 12m. Most patients remained on combination anti-malarial, GC, and IS at all follow-up time points. The median [IQR] GC dose at the index visit was 10 [5, 20] mg/day; this reduced to 8 mg [5.0, 12.9] at 6m and 5 mg [5.0, 10.0] at 12m. Less than a quarter of patients attained LLDAS and only 1% attained GC-free remission over 12 months. A draft definition of srSLE was clearly associated with poor outcomes. Work to evaluate multiple thresholds with which to define srSLE, and their outcomes, is warranted.