The systemic lupus erythematosus Disease Activity Score (SLE-DAS) aims to provide a practical, accurate, and sensitive to change tool to measure the activity of SLE.¹ This new tool addresses the pitfalls of the previously available instruments. The SLE-DAS is useful in routine clinical practice to quantify global disease activity. It enables clinicians to accurately classify disease activity as mild, moderate, or severe, guiding therapeutic decisions. In longitudinal follow-up, the SLE-DAS objectively assesses response to treatment and identifies SLE flares. Not the least, the SLE-DAS identifies the treatment targets of remission and low disease activity (LDA).

The SLE-DAS is a validated instrument, with 17 weighted clinical and laboratory parameters, including continuous measures for arthritis, proteinuria, thrombocytopenia, and leukopenia.¹ The SLE-DAS was derived using real patients’ data collected in regular follow-up at referral lupus clinics, applying multivariate linear regression using the Physician Global Assessment (PGA) as a dependent variable. It presents a well-balanced weighting system and includes less frequent SLE manifestations, such as cardiopulmonary, gastrointestinal, opthalmological involvement, and hemolytic anemia, making it a comprehensive tool to measure SLE disease activity. The SLE-DAS is readily available with the SLE-DAS online calculator (freely available at http://sle-das.eu/), taking only 1–2 minutes to score each patient.

Validation studies have shown that the SLE-DAS presented face, construct, criterion, and content validity.² A longitudinal follow-up of patients in two real-life cohorts demonstrated SLE-DAS’ high predictive value for damage accrual. Longitudinal validation demonstrated that a SLE-DAS change ≥1.72 presented 95.5% sensitivity and 98.2% specificity for identifying a clinically meaningful worsening, and 89.5% sensitivity and 100% specificity for identifying a clinically meaningful improvement, thus demonstrating its high responsiveness.

Both the SLE-DAS definition for remission (SLE-DAS clinical items=0, and prednisolone dose ≤5 mg/day) and LDA (SLE-DAS ≤2.48, and prednisolone dose ≤7.5 mg/day), were derived and validated in two multicentre real-life cohort studies.^{1 3 4} A post-hoc analysis of the belimumab Phase 3 ^5–7 clinical trials demonstrated the discriminant ability of both SLE-DAS remission and LDA for identifying patients receiving active drug or placebo. Moreover, attainment of SLE-DAS remission or LDA was associated with greater health-related quality of life and improved fatigue.⁵

The SLE-DAS definitions for categories of mild, moderate and severe disease activity were derived and validated in a large multicentre, multiethnic cohort.^{2 6 7} Another clinical trial population highlighted the association these categories with differences in all domains of health related quality of life and fatigue.² The SLE-DAS also presented high performance, in assessing flares and allowing to identify mild, moderate, and severe flares.⁸

The SLE-DAS may provide an optimised primary efficacy endpoint for SLE clinical trials,⁹ integrated into a tool able to identify candidates for trials, assess flares, and attainment of treatment targets, that are associated with meaningful impact in the main health aspects of importance to patients.

References

1. Jesus D, Matos A, Henriques C, et al. Derivation and validation of the SLE disease activity score (SLE-DAS): A new SLE continuous measure with high sensitivity for changes in disease activity. Ann Rheum Dis. 2019;78(3):365–71. doi: 10.1136/annrheumdis-2018-214502.

2. Inês LS, Fredi M, Jesus D, et al. What is the best instrument to measure disease activity in SLE? - SLE-DAS vs EASY BILAG. Autoimmun Rev. 2024;23(1):103428. doi: 10.1016/j.autrev.2023.103428.

3. Jesus D, Larosa M, Henriques C, et al. Systemic lupus erythematosus disease activity score (SLE-DAS) enables accurate and user-friendly definitions of clinical remission and categories of disease activity. Ann Rheum Dis. 2021;80(12):1568–74. doi: 10.1136/annrheumdis-2021-220363.

4. Assunção H, Jesus D, Larosa M, et al. Definition of low disease activity state based on the SLE-DAS: Derivation and validation in a multicentre real-life cohort. Rheumatology (Oxford). 2022;61(8):3309–16. doi: 10.1093/rheumatology/keab895.

5. Jesus D, Henriques C, Matos A, et al. Systemic lupus erythematosus disease activity score remission and low disease activity states discriminate drug from placebo and better health-related quality of life. Arthritis Care Res 2024;76(6):788–95. doi: 10.1002/acr.25305.

6. Furie R, Petri M, Zamani O, et al. A Phase III, randomized, placebo-controlled study of belimumab, a monoclonal antibody that inhibits B lymphocyte stimulator, in patients with systemic lupus erythematosus. Arthritis Rheum. 2011;63(12):3918–30. doi: 10.1002/art.30613.

7. Navarra SV, Guzmán RM, Gallacher AE, et al. Efficacy and safety of belimumab in patients with active systemic lupus erythematosus: A randomised, placebo-controlled, Phase 3 trial. Lancet. 2011;377(9767):721–31. doi: 10.1016/s0140-6736(10)61354-2.

8. Saraiva L, Cunha RN, Jesus D, et al. The SLE-DAS provides an accurate and feasible flare tool in the clinical setting: A validation study. Rheumatology (Oxford). 2024;63(4):1123–9. doi: 10.1093/rheumatology/kead353.

9. Jesus D, Henriques C, Matos A, et al. POS0733 Validation of the SLE-DAS responder Index an an accurante and feasible endpoint for SLE clinical trials: A post-hoc study in the Phase 2 and 3 anifrolumab clinical trials. Ann Rheum Dis. 2024;83:1004–5. doi: 10.1136/annrheumdis-2024-eular.4639.

Learning Objectives At the end of this presentation participants will be able to:

• Explain the benefits of the SLE-DAS compared to previous methods for measuring SLE disease activity

• Describe the key features of the SLE-DAS scoring system

• Explain the potential impact of SLE-DAS on treatment decisions and patient outcomes