Pattern of proteinuria in IgA nephropathy

Summary: Proteinuria is one of the bad prognostic indices in IgA nephritis (IgAN). This study compares the pattern of protein excretion in 10 patients with IgAN (IA) with that 5 years later (IB), when they developed renal impairment or hypertension. The pattern of proteinuria was analysed by SDS-PAGE and isoelectric focusing (IEF) and assayed for orosomucoid, α-1-microglobulin, retinol-binding protein, lysozyme, beta-2-microglobulin and N-acetyl-β-D-glucosaminidase activity. The data suggest that the changing pattern of proteinuria from IgA₁ to IgA₂ may reflect hyperfiltration as well as tubular injury.