Clinical characteristics of 1020 childhood-onset systemic lupus erythematosus: data from a health centre in China

Objective Childhood-onset systemic lupus erythematosus (cSLE) is a multisystem autoimmune disease characterised and presents partially differently from adults. A large cSLE cohort study is lacking in China. The present study aimed to determine the clinical characteristics in a large population of patients with cSLE, and compare with adult-onset SLE (aSLE) in an SLE cohort of China. Methods The retrospective study included patients with cSLE diagnosed at the Beijing Children's hospital between July 2006 and October 2020. All patients met at least 4 of ACR classification criteria for SLE. In addition, data including demographic, clinical and serologic data were collected. Our data were compared with other cSLE cohorts and Chinese aSLE cohorts. Results A total of 1020 patients were included in this study, comprising 808 female and 212 male patients (female to male ratio, 3.8:1). The mean age at diagnosis of lupus was 11.1 years (range 1.0-17.2). It took on average 6 months (range 0.1- 132) from first symptoms to cSLE diagnosis and over 12 months in 12% of patients. The most common primary manifestations at onset were rash ( 37.2%), fever (33.4%), nephropathy ( 14.2%) and arthritis (13.6%). The most common clinical manifestations were rash (67.9%) and fever (57.5%). 59.4% of patients had haematological involvement, 46.0% had lupus nephritis, 33.2% had arthritis. cSLE was more active and associated with more inflammation than aSLE patients. Conclusion This study is a large single-centre study on cSLE from China and clarifies the clinical phenotype and autoantibody spectrum of cSLE. The clinical manifestations and autoantibody spectrum of cSLE are diverse, with regional and populational differences.