Abstract
Background Very limited and old data regarding the epidemiology of juvenile-onset SLE (jSLE) are available. Our aim was to estimate jSLE incidence and mortality rate in incident cases over the period 2012–2020. In addition, we also assessed point prevalence of pediatric SLE in 2020.
Methods This is a retrospective population-based study conducted using the Veneto Region Population Registry, an administrative health database where all residents are recorded (4.9 million people), which was linked to the mortality register. SLE cases were identified by any hospital diagnosis of SLE (ICD-9-CM 710.0), or a healthcare copayment exemption for SLE (national registry code 028), whichever came first, between 2021 and 2020. All SLE diagnoses in subjects <19 years-old were considered. Standardized incidence rate (IR) was reported by gender. Standardized point prevalence of pediatric SLE was assessed considering prevalent SLE cases aged <19 years-old in 2020.
Results During the study period, among 1,092 incident SLE cases, 68 (6.2%) were jSLE (54 females, 79.4%). IR (95%CI) over the study period was 0.94 overall: 0.38 (0.23–0.63) x 100,000 residents in males, and 1.54 (1.18–2.01) x 100,000 in females. This incidence rate was significantly lower than those observed in other age groups (age groups 19–44, 45–60, 60–75, >75 years). Incidence was 4-folds higher in females (female-to-male IR ratio: 4.09, 95% CI 2.27–7.36, p<0.0001). No death occurred among the incident cases of jSLE. In 2020, 34/3,472 prevalent SLE patients were <19 years-old (1%); point prevalence of pediatric SLE was 3.9 (2.6–5.2) per 100,000 residents, significantly lower than that of adults SLE (71.2, 68.8–73.5). No death occurred among the incident cases of jSLE.
Conclusions Between 2012 and 2020, jSLE incidence was 1:10,000 residents, confirming that pediatric SLE is a rare condition, as reported in older studies in other European countries. Over the last decade, early jSLE mortality has been negligible.
