[Epidemiology of systemic lupus erythematosus in Reunion Island, Indian Ocean: A case-series in adult patients from a University Hospital]

Objectives: The study aimed at assessing the epidemiology and clinical features of systemic lupus erythematosus (SLE) in Reunion Island, South West of Indian Ocean.

Patients and methods: A retrospective study was conducted at the University Hospital of La Reunion (Saint-Denis) by charts review from 2004 to 2015. Patients with a SLE diagnosed over 15 years according to SLICC 2012 criteria were included. Incidence and prevalence were inferred from national health insurance database and population census results.

Results: In total, 123 patients met inclusion criteria: 116 were women (94%) and mean age at diagnosis was 34.7±13.4 years. Ten percent of all patients had a least one parent with autoimmune disease, and 4% with lupus. The main manifestations were musculoskeletal (89%) and mucocutaneous with acute or subacute lesions (76%), alopecia (25%), ulcers (15%) and discoid lupus (11%). Lupus nephropathy occurred in 39%, serositis in 31% and neurological features in 15%. Antinuclear antibodies were positive in 99% (threshold >1/80), and associated to anti-DNA (70%), anti-SSA (47%), anti-RNP (42%), and anti-Sm (37%). APL syndrome was diagnosed in 15%. The average annual standardized incidence between 2010 and 2016 was 6.3 cases per 100,000 inhabitants (95% confidence interval [CI]: 5.6-6.9). The prevalence was 76 cases per 100,000 inhabitants in 2016 (95% CI: 70-82).

Conclusion: Lupus in the multi-ethnic population of Reunion Island is characterized by high incidence and high rates of articular and renal manifestations, as well as anti-ENA antibodies.