Hospitalised infections and rituximab administration among children and adolescents with systemic lupus erythematosus from 2009 to 2021.

ABSTRACT

BACKGROUND: Rituximab is associated with high infection rates, but studies of infections following rituximab in youth with childhood-onset SLE (cSLE) are limited. We conducted a retrospective longitudinal cohort study to assess the incidence of hospitalised infections following rituximab among children with cSLE and to assess changes in hospital-based rituximab administration over time. METHODS: Youth ages 2-21 years with an International Classification of Diseases (ICD) code for SLE who received rituximab during admission to a Pediatric Health Information System hospital from 2009 to 2021 were included. Incidence rates for infections requiring hospitalisation over the 12 months following first rituximab administration were calculated. Rituximab use by year of hospital discharge was tabulated. RESULTS: We identified 1567 children with cSLE who received rituximab. 219 children were admitted with an infection within 1 year after first rituximab administration, for an incidence rate of 140 cases per 1000 patient-years. Seven children (0.44%) died during a hospitalisation with an infection in the year following rituximab administration. The most common hospitalised infections were bacterial pneumonia, sepsis and cellulitis. 12 children were hospitalised with COVID-19, none of whom died. Hospitalisations with rituximab administered decreased from 2019 to 2021. CONCLUSIONS: In this cohort of patients with cSLE who received inpatient treatment with rituximab, we observed a 14% rate of hospitalisation with infection in the year following rituximab administration among youth with cSLE. Rituximab use declined during the COVID-19 pandemic. No fatalities with COVID-19 were observed. Given the lack of outpatient data, including doses of concomitant medications and disease activity measures, further research is needed to identify risk factors for infection following rituximab among children with cSLE.