The scope of treatment of pediatric IgA vasculitis nephritis and its outcome: a Pediatric Nephrology Research Consortium study

Background: IgA vasculitis (IgAV) is the most common type of vasculitis in children. There is a lack of consensus for management of significant IgAV nephritis (IgAVN). This study was designed to identify the most used treatment options and describe their efficacy. Methods: This is a multicenter retrospective study of children age 1–21 years with IgAVN who were managed for at least 6 months by a nephrologist. Subjects with at least microscopic hematuria and proteinuria and/or decreased kidney function were enrolled. Kidney outcome was assessed by eGFR and urine protein/creatinine (UPC) ratios at 2–4 weeks, 3, 6, and 12 months post-diagnosis. Results: A total of 128 subjects with median age of 7 years (range 2–18) were included. Of these, 69 subjects had kidney biopsy with crescents detected in 53%. AKI (P = 0.039), nephrosis (P = 0.038), and crescents on biopsy (P = 0.013) were more likely in older patients. Patients with UPC > 1 mg/mg were more likely to get a kidney biopsy (P < 0.001) and to be treated with steroids ± immunosuppressive (IS) agents (P = 0.001). Sixty-six percent of patients were treated with steroids and/or IS agents for variable durations. Anti-metabolite agents were the most common IS agents used with variability in dosing and duration. At 12 months, most subjects had a normal eGFR (79%) (median 123, range 68–207 mL/min/1.73 m²) and no proteinuria (median UPC 0.15, range 0.01–4.02 mg/mg). Conclusions: IS agents are frequently used in managing IgAVN associated with heavy proteinuria, nephrosis, and/or AKI. Prospective studies are needed to determine indications and needed duration of IS therapy. Graphical abstract: A higher resolution version of the Graphical abstract is available as Supplementary information. [Figure not available: see fulltext.]