In this study, we report for the first time an increased urinary excretion of VTDB (Vitamin D binding protein), A2GL (Leucin-rich alpha-2-glycoprotein), AFAM (Afamin) and HEMO (Hemopexin) in patients with more severe IgA nephropathy, and suggest these proteins to be predictive biomarkers for severity of IgA nephropathy. Here, AFM is linked to IgA glomerulonephritis.