To assess the impact of achieving Lupus Low Disease Activity State ≥50% of the time (LLDAS-50) on damage accrual and mortality in an inception cohort of patients with systemic lupus erythematosus (SLE).
We used data from the Tromsø Lupus Cohort, a longitudinal population-based study of all patients with SLE in the 2 northernmost counties in Norway. LLDAS was defined as 1) a Systemic Lupus Erythematosus Disease Activity Index 2000 score of ≤4, with no activity in major organ systems, 2) no new features of lupus disease activity, 3) current therapy with prednisolone (or equivalent) dosage of ≤7.5 mg daily, and 4) well-tolerated standard maintenance dosages of immunosuppressive drugs.
A total of 69 patients (33.5%) spent at least half of their follow-up time in LLDAS (thus, achieving LLDAS-50) and had significantly better survival and lower risk of developing severe damage over time, according to the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. After correcting for age and sex, LLDAS-50 was associated with a significant reduction in risk of having severe damage (hazard ratio [HR] 0.37 [95% confidence interval (95% CI) 0.19-0.73], P < 0.01), and also a reduction in mortality (HR 0.31 [95% CI 0.16-0.62], P < 0.01).
Our study validates the findings of the inception cohort by demonstrating that achievement of LLDAS-50 is associated with a significant reduction in severe damage and, for the first time, demonstrates a reduction in mortality.