Outcomes of achieving lupus low disease activity state and damage accrual in childhood-onset systemic lupus erythematosus.

ABSTRACT

INTRODUCTION: At present, the treat-to-target approach has been proposed with the lupus low disease activity state (LLDAS) as an achievable target. OBJECTIVES: To determine damage accrual and baseline clinical characteristics associated with achieving LLDAS within 12 months of treatment in patients with childhood-onset systemic lupus erythematosus (c-SLE). METHODS: This retrospective cohort study was conducted at the largest university-based tertiary referral center in Thailand. Data of c-SLE patients (≤ 18 years) at diagnosis who were followed ≥ 12 months during January 2009 to December 2019 were collected. SLE disease status was categorized into LLDAS and non-optimally controlled state. SLEDAI-2K score was used to assess disease activity. Damage accrual was assessed by a pediatric version of the SLICC/ACR damage index. RESULTS: A total of 232 c-SLE patients (85.8% female) were included. At 12 months of treatment, 109 (47%) patients achieved LLDAS. Damage accrual was observed in 93 (40.1%) patients at the mean follow-up time of 6.2 ± 3.7 years. Damage accrual was significantly lower in patients who achieved LLDAS within 12 months than in those non-optimally controlled (p = 0.002). The median time to achieving LLDAS was 12.6 months (95%CI 11.19-13.97). The median time to achieving LLDAS was significantly shorter in those without renal involvement (10.8 months, 95%CI 9.62-12.00 vs. 15.6 months, 95%CI 13.76-17.52, respectively; p = 0.044). Multivariable logistic regression analysis revealed absence of renal involvement as the predictor of achieving LLDAS within 12 months of treatment (aOR 2.430, 95%CI 1.420-4.158; p = 0.001). CONCLUSIONS: Achieving LLDAS within 12 months of treatment was associated with lower damage accrual. Absence of renal involvement was the predictor of achieving LLDAS within 12 months of treatment. Key Points • LLDAS is a promising and achievable treatment target in c-SLE. • Achieving LLDAS within 12 months of treatment is associated with lower damage accrual. • Absence of renal involvement is the predictor of achieving LLDAS within 12 months of treatment.