SLE patients with childhood-onset: A nation-wide population-based study

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that typically affects women of childbearing age. Using a nationwide database, we aimed to assess the prevalence, main clinical features and outcomes of patients with childhood-onset SLE (cSLE). Data on all patients admitted to a French hospital between January 2011 and December 2020 with at least one ICD, 10th revision code for SLE were retrieved from the nationwide hospital medical information database. Individuals who developed systemic SLE before the age of 17 years were considered to have cSLE. Between 2011 and 2020, 36,791 unique SLE patients were hospitalised in France. Among them, 1030 individuals younger than 17 years (median [q1-q3] age 13.0 [11.0;15.0]) years, 81.9 % female) were identified as having cSLE. The prevalence of cSLE was 8.3 cases per 100,000 inhabitants. The main characteristics of cSLE did not differ by sex, except for a younger age of onset in boys. Older children have a higher incidence of lupus nephritis. Compared to adult-onset SLE, lupus nephritis and immune cytopenia were twice as frequent in cSLE. During a median follow-up of 7.1 [4.0-9.0] years, 539 (52.3 %) cSLE patients experienced at least one hospitalisation for an infection. A total of 6 patients (0.6 %) died. All of these deaths occurred during the hospitalisation in which the first lupus code was assigned. The prevalence of cSLE in France was 8.3 cases per 100,000 of the population. cSLE had a higher rate of renal nephritis and immune cytopenia than adult-onset SLE.