Impact of high disease activity on damage accrual and disease outcomes in childhood-onset systemic lupus erythematosus.

Objective: The impact of the duration and cumulative high disease activity on damage accrual in childhood-onset SLE (cSLE) is less well established. This study aimed to assess the cumulative burden of high disease activity and its association with damage accrual and clinical outcomes in patients with cSLE. Methods: This retrospective cohort study included cSLE patients with at least one year of follow-up. High disease activity status (HDAS) was defined as a SLEDAI-2 K score ≥10. Patients were classified into two groups: HDAS (ever experienced HDAS) and non-HDAS. Time-adjusted cumulative HDAS (cHDAS) was defined as the proportion of time spent in HDAS during the observation period. Clinical features, laboratory parameters, treatment, organ damage assessed by the SLICC/ACR Damage Index, and remission status were recorded at baseline and each follow-up visit. Logistic regression, Cox proportional hazards models, and Kaplan-Meier analyses were performed. Results: Among 196 cSLE (mean age at diagnosis 11.3 ± 2.9 years; 82.1% female), 126 (64.3%) experienced high disease activity status (HDAS). Patients with HDAS had a significantly higher rate of damage accrual than those without (SDI ≥ 1: 33.3% vs. 11.4%, Conclusions: Higher time-adjusted cHDAS was associated with an increased risk of damage accrual, indicating that greater cumulative exposure to high disease activity is associated with damage. Neuropsychiatric involvement and time-adjusted cHDAS ≥5% were significantly associated with damage accrual.