Chinese Systemic Lupus Erythematosus Treatment and Research Group Registry IX: Clinical Features and Survival of Childhood-Onset Systemic Lupus Erythematosus in China

BACKGROUND: Approximately 15–20% cases of systemic lupus erythematosus (SLE) are diagnosed in children. There have been a few studies reporting the epidemiological data of pediatric-onset SLE (cSLE) in China, neither comparing the differences between cSLE and adult-onset SLE (aSLE). The aim of this study was to describe the impact of age of onset on clinical features and survival in cSLE patients in China based on the Chinese SLE Treatment and Research group (CSTAR) database. METHODS: We made a prospective study of 225 cSLE patients (aged < 16 years) and 1759 patients aged 16–50 years based on CSTAR registry. We analyzed initial symptoms, clinical presentations, SLE disease activity, damages, and outcomes of cSLE, as well as compared with aSLE patients. RESULTS: The mean age of cSLE patients was 12.16 ± 2.92 years, with 187 (83.1%) females. Fever (P < 0.001) as well as mucocutaneous (P < 0.001) and renal (P = 0.006) disorders were found to be significantly more frequent in cSLE patients as initial symptoms, while muscle and joint lesions were significantly less common compared to aSLE subjects (P < 0.001). The cSLE patients were found to present more frequently with malar rash (P = 0.001; odds ratio [OR], 0.624; 95% confidence interval [CI], 0.470–0.829) but less frequently with arthritis (P < 0.001; OR, 2.013; 95% CI, 1.512–2.679) and serositis (P = 0.030; OR, 1.629; 95% CI, 1.053–2.520). There was no significant difference in SLE disease activity index scores between cSLE and aSLE groups (P = 0.478). Cox regression indicated that childhood onset was the risk factor for organ damage in lupus patients (hazard ratio 0.335 [0.170–0.658], P = 0.001). The survival curves between the cSLE and aSLE groups had no significant difference as determined by the log-rank test (0.557, P = 0.455). CONCLUSIONS: cSLE in China has different clinical features and more inflammation than aSLE patients. Damage may be less in children and there is no difference in 5- year survival between cSLE and aSLE groups.