Specific molecular biomarkers were detected in kidney biopsy of IgA nephropathy characterizing active (E and C) and chronic (T) renal lesions compared with other non-IgA glomerulonephritis and living donors Overall design: RNA was extracted from archival FFPE biopsy samples of 52 IgAN patients, 22 non-IgAN glomerulonephritis (non-IgAN GN) and 7 kidney living donors (LD). Genome-wide gene expression profiles were generated and stringent statistical analysis identified transcripts associated with active and chronic renal lesions. gAN patients were scored using the MEST-C classification by three pathologists (MR, BMA, CG) and stratified into 4 groups with different composite renal lesions: minimal N.22 (M0,1; E0; S0,1; T0; C0); active N. 8 (M0,1; S0,1; T0; E1 and/or C,1,2); chronic N:12 (M0,1; E0; S0,1; T1,2; C0); mixed group of active and chronic lesions N.10(M0,1; E0,1; S0,1; T1,2; C0,1,2).