The most widely used composite disease activity score for systemic lupus erythematosus. Scores 24 clinical and laboratory features weighted by organ domain and severity. Used in clinical trials, treat-to-target monitoring, and biologic drug approval criteria for lupus.
SLEDAI-2K is a point-weighted composite disease activity score for SLE that evaluates 24 features across nine organ domains. Each feature carries a weight of 1, 2, 4, or 8 points depending on its clinical severity and relevance. The maximum possible score is 105, though scores above 20 are uncommon in clinical practice.
The "2K" version (Gladman et al., 2002) differs from the original 1992 SLEDAI in that it also scores persistent activity for rash, alopecia, mucous membrane ulcers, and proteinuria. Lupus headache and visual disturbance are scored only when new or recurrent.
The bands below are one commonly used convention, cited from published SLE studies and trial protocols. Published cut-offs vary, so state the convention you use when reporting or comparing scores. Other schemes, including 3-tier and 4-tier versions, are also in use.
Convention source: Table 2, Indian SLE cohort (2020;36(2):185-193, doi:10.1007/s12291-020-00879-5); clinical-trial protocol NCT02554019.
| SLEDAI-2K score | Activity state | Clinical meaning |
|---|---|---|
| 0 | No activity | No active SLE manifestations in the past 10 days. A common treatment target. |
| 1 to 5 | Mild activity | Low-level manifestations. Review the overall treatment plan and monitor closely. |
| 6 to 10 | Moderate activity | Active manifestations that may warrant review of current treatment. |
| 11 to 19 | High activity | Significant active disease. Assess for major organ involvement. |
| 20 or more | Very high activity | Very high disease activity. Assess for major organ involvement without delay. |
Treatment-prediction cut-off (active disease): a SLEDAI-2K of 3 or 4 was the most appropriate cut-off for active disease when increase in therapy was the reference standard (Yee et al., ROC analysis, PMC3077910). This is a statistical cut-off for predicting treatment change. It is not the LLDAS definition: see the LLDAS calculator.
A change of 4 or more points is generally considered the minimal clinically important difference (MCID) for SLEDAI-2K in clinical trials. The SRI-4 response (used in belimumab and anifrolumab trials) requires a 4-point or greater reduction in SLEDAI-2K.
The original SLEDAI was developed by Bombardier, Gladman, and colleagues at the University of Toronto and published in Arthritis and Rheumatism in 1992. It was derived from expert opinion and validated against physician global assessment and subsequent organ damage. The SLEDAI-2K revision was published by Gladman et al. in the Journal of Rheumatology in 2002, with the key modification allowing persistent activity to be scored for rash, alopecia, mucous membrane ulcers, and proteinuria.
Validation studies have demonstrated that SLEDAI-2K correlates with physician global activity, distinguishes active from inactive disease, and predicts subsequent organ damage accrual. The SRI-4 response criterion, defined as a 4-point or greater SLEDAI-2K reduction, was developed for the BLISS-52 and BLISS-76 belimumab trials and has become the standard efficacy endpoint in SLE trials.