JUVENILE SYSTEMIC LUPUS ERYTHEMATOSUS IN QUEENSLAND'S INDIGENOUS POPULATION: CLINICAL MANIFESTATIONS AND SEVERITY AT DIAGNOSIS (2014-2021)

Abstract

Objectives: To compare the diagnostic clinical manifestations, severity at presentation, and time to diagnosis of juvenile Systemic Lupus Erythematosus (jSLE) in Indigenous versus non-Indigenous patients in Queensland, Australia. Methods: Children diagnosed with jSLE between 2014 and 2021 and managed by the Rheumatology department at the Queensland Children's Hospital, had demographic, clinical and laboratory data collected from their electronic medical record and subsequently analysed. BILAG- 2004 and SLEDAI-2K scores at diagnosis were retrospectively calculated and included for analysis. Results: Of the 38 children diagnosed with jSLE, 31.6% were Indigenous (comprising the largest ethnic group in our study), and 26.3% were Caucasian. The most common diagnostic clinical features in Indigenous children were fever (58.3%) and arthritis (41.7%). Indigenous children were significantly less likely to present with acute cutaneous lupus compared to non-Indigenous children (25% vs 69.2%; p = 0.02). Retrospective application of BILAG-2004, demonstrated non-significant trends towards higher rates of severe disease in Indigenous children versus non-Indigenous children for multiple organ systems - haematologic (50% vs 16%), constitutional (33% vs 23%), neuropsychiatric (8% vs 0%), musculoskeletal (33% vs 27%), cardiorespiratory (25% vs 8%) and gastrointestinal (8% vs 4%). The incidence rate of lupus nephritis for Indigenous children was 20.2 cases per 100 person-years at risk (95% CI 5.5 to 51.73), versus 13.7 cases per 100 person- years at risk (95% CI 5.91 to 26.99) for non-Indigenous children. Median time to diagnosis was similar between Indigenous and non-Indigenous children (median 1.25 months vs 1.94 months). Conclusions: This is the first jSLE study focusing on Indigenous Australians. Indigenous children were over-represented in our cohort suggesting increased rates of jSLE in this population. Compared to non- Indigenous children, Indigenous children demonstrated increased severity of disease at presentation, with no significant difference in time to diagnosis, although these results were limited by small sample sizes.