Definition of low disease activity state based on the SLE-DAS: derivation and validation in a multicentre real-life cohort

Abstract

Objectives To derive and validate a definition of low disease activity (LDA) for systemic lupus erythematosus (SLE) based on the SLE Disease Activity Score (SLE-DAS), in a real-life multicentre cohort of SLE patients. Methods Derivation was conducted using data from a monocentric cohort of SLE (Portugal), and validation was performed in a multicentre cohort (Italy, France, and Spain). The Lupus Low Disease Activity State (LLDAS) was used as comparator. We applied receiver operating characteristics (ROC) curve analysis against the LLDAS to determine the cut-off of SLE-DAS for LDA using bootstrap methodology. In a second step, we tested a definition of SLE-DAS LDA that included: (i) the statistically derived SLE-DAS upper threshold for LDA, and (ii) prednisone dose ≤7.5 mg/day. In the multicentre validation cohort, we assessed the classification performance of this SLE-DAS LDA definition. Results We included 774 patients, 300 in the derivation and 474 in the validation cohorts, respectively. In the derivation cohort, the optimal cut-off to identify patients in LLDAS was SLE-DAS ≤2.48, presenting an area under the curve (AUC) of 0.965 (95%CI 0.935–0.994). When applied to the multicentre validation cohort, the SLE-DAS LDA definition showed a sensitivity of 97.1% and a specificity of 97.7% for LLDAS and an almost perfect agreement (Cohen’s Kappa =0.933; p< 0.001). McNemar’s test found no significant differences between the two definitions (p= 0.092). Conclusion The SLE-DAS LDA is a validated, accurate, and easy-to-use definition for classifying SLE patients in LDA state.

Systemic Lupus Erythematosus Disease Activity Score Remission and Low Disease Activity States Discriminate Drug From Placebo and Better Health‐Related Quality of Life

“…12 The SLE-DAS presented face, construct, and criterion validity. [12][13][14] In longitudinal validation SLE-DAS presented high accuracy for detecting changes in SLE disease activity and high predictive value for damage accrual, thus demonstrating responsiveness and criterion validity. 12,13 A SLE-DAS change ≥1.72 presented 89.5% sensitivity and 100% specificity to discriminate a clinically significant improvement and 95.5% sensitivity and 98.2% specificity to discriminate a clinically significant worsening.…”

Defining the targets in SLE management: insights and unmet gaps

“…A new measure of disease activity, the SLE disease activity score, has been proposed to overcome these limitations, related to the dichotomous nature of the SLEDAI-2k, 32 with cutoffs for remission 33 and LDA also derived and validated. 34 It would be interesting to see its performance in capturing patients with clinical LDA in different cohorts.…”

“…; LLDAS, lupus low disease activity state, Franklyn et al 64; SLE-DAS LDA, SLE-DAS definition of low disease activity, Assunção et al 3414.…”

“…As LDA suffers from a lack of defined borders discriminating it from remission, some effort is still needed to clearly depict what LDA is in lupus, including its definition and prevalence. A new measure of disease activity, the SLE disease activity score, has been proposed to overcome these limitations, related to the dichotomous nature of the SLEDAI-2k,32 with cut-offs for remission33 and LDA also derived and validated 34. It would be interesting to see its performance in capturing patients with clinical LDA in different cohorts.…”

Combination treatment with rituximab and belimumab in shrinking lung syndrome in systemic lupus erythematosus

“…prednisolone tapering to 7.5 mg/day since January 2021, with attainment of low disease activity. 1,2 In November 2021, our patient was admitted to the Rheumatology ward due to gradually progressive exertional dyspnea, orthopnea, pleuritic chest pain, and dry cough for the past year, despite diuretic therapy. There was no recent history of fever or current infections.…”