Increased incidence of juvenile-onset systemic lupus erythematosus among children with asthma

Background: Children with systemic lupus erythematosus (SLE) have an especially aggressive disease course and poor outcomes. Previous studies demonstrated a possible association between SLE and allergies, but the relationship between these disorders remains unclear. This population-based cohort study aimed to investigate the incidence and risk of juvenile-onset SLE (JSLE) among children with asthma. Methods: From 2000 to 2003, 120,939 children with newly diagnosed asthma and 483,756 randomly selected non-asthma controls were enrolled. We used a multivariable Cox proportional hazard regression model to measure and compare the incidence rate and risk of JSLE in the asthma and non-asthma cohorts. Results: The overall incidence of JSLE was 2.52 times greater in the asthma cohort than that in the non-asthma cohort [3.49 vs. 1.53 per 100,000 person-years; 95% confidence interval (CI): 1.59-3.99]. The risk of JSLE was greatest among boys [hazard ratio (HR) 3.02, 95% CI: 1.21-7.52] and children aged 6-10 yr (HR 3.50, 95% CI: 1.75-7.02). The HR of JSLE increased with greater frequency of asthma-related medical visits from 1.22 (95% CI: 0.67-1.41) for those with <= 2 visits/yr to 5.88 (95% CI: 3.43-10.1) for subjects with >2 visits/yr (trend test p < 0.001). However, the risk of JSLE declined over time. Conclusion: We found an increased incidence of JSLE among children with asthma. The mechanism of asthma on JSLE development should be elucidated to establish innovative disease intervention programs.