Iga-Vasculitis

The first evidence-based guidelines for adult-onset IgA vasculitis, from the European Vasculitis Society, give 14 recommendation statements and four overarching principles covering diagnosis, work-up, organ-specific treatment and follow-up. Adult disease is rarer than in children but more severe and persistent, and kidney involvement decides the long-term outcome. The strongest evidence behind any statement is level 2b and the highest grade is B, so most of the advice rests on observational data and expert consensus.

IgA vasculitis and IgA nephropathy share HLA susceptibility, 21 GWAS risk loci, elevated Gd-IgA1 and renal biopsies that cannot be told apart — yet IgAN now has five approved therapies and IgAV has none, because IgAV patients were excluded from every trial that delivered them. What changes today: KDIGO 2025 lowers the treatment threshold to 0.5 g/day of proteinuria, and it explicitly covers IgA vasculitis.