Clinical features and outcomes of the adult Singapore IgA Vasculitis Cohort

Immunoglobulin A (IgA) vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is an immune-mediated small vessel vasculitis that has a predilection to affect the joints, kidneys, gastrointestinal tract and skin.1,2 It is the most frequent systemic vasculitis in children, and while less common in adults, it is often associated with more severe disease. Geographical differences have been reported in the prevalence of adult IgAV including male predominance, gastrointestinal involvement and musculoskeletal complications among Europeans, and lower propensity for genitourinary involvement among Americans.3 The frequency of glomerulonephritis (referred to as IgAV nephritis) in adults is higher than in children and tends to present more severely, with approximately 10–30% of those affected eventually progressing to end-stage renal disease.4 There have been several published case series and cohort studies of adult IgAV from the Asia-Pacific region, predominantly from East and Central Asia, but with a paucity of reports from Southeast Asia.5,6