A retrospective study of long-term outcomes related with initial factors in childhood onset systemic lupus erythematosus

Background: Childhood onset systemic lupus erythematosus (cSLE) exhibits more severe and more aggressive clinical features compared to adult onset SLE. We investigated factors associated with long-term outcomes among the initial parameters at the time of diagnosis in cSLE. Patients and methods: This study included patients initially diagnosed with cSLE who were less than 18 years old between January 2009 and December 2021. We excluded patients with prior diagnoses, those transferred from another hospitals, individuals with clinical findings related to infection or post-transplantation, and underlying diseases. A retrospective review of electronic medical records was conducted to gather initial laboratory data, and assess clinical manifestations, including SLE disease activity index-2K (SLDAI-2k). We analyzed parameters associated with survival, as well as events such as flare, complications, and new organ involvement. Results: A total of 109 patients were enrolled in this study. The mean age was 14.4 ± 2.3 years old, and the female to male ratio was 7.4:1. Twenty-eight patients (25.7%) were diagnosed during the pre-pubertal period. The overall survival rate was 92.9 % (median: 5.0 years). The causes of death were intractable macrophage activation syndrome (n = 2), disease related state (n = 2), and infection (n = 2). The factors related to survival were elevated C-reactive protein (CRP, p = .017, HR: 2.396, 95% CI: 1.165 ∼4.926) in multi-variate analysis, although there were association with CRP, SLEDAI-2K, and false positivity for syphilis (p < .05) in univariate analysis. The event free survival was 10.4% and was related to SLEDAI-2K, anti-Smith antibody, and false positivity for syphilis (p < .05) in univariate analysis. In multivariate analysis, factors associated with event were SLEDAI-2K (p = .035, HR: 2.82, 95% CI: 1.078∼7.375) and, anti-Smith antibody (p = .019, HR: 3.262, 95% CI: 1.218∼8.741). Conclusion: Initial SLEDAI-2K and bio-markers for immune response were related to survival and events during follow-up. Clinicians should focus on initial disease activity and laboratory parameters when predicting long-term outcomes in cSLE.