title: LG3 fragment of endorepellin is a possible biomarker of severity in IgA nephropathy.
abstract: IgA nephropathy (IgAN), the most common primary glomerulonephritis, is characterized by deposition of IgA in the glomerular mesangium. The diagnosis of IgAN still requires a kidney biopsy that cannot easily be repeated in the same patient during follow-up. Therefore, identification of noninvasive urinary biomarkers would be very useful for monitoring patients with IgAN. We first used bidimensional electrophoresis (2DE) coupled to MALDI-TOF-TOF and Western blot to identify some urinary biomarkers associated with IgAN. Urine of IgAN patients showed an increase of albumin fragments, α-1-antitrypsin and α-1-β-glycoprotein, along with a decrease of a single spot that was identified as the laminin G-like 3 (LG3) fragment of endorepellin. The urinary proteomes of 43 IgAN patients were compared to those of 30 healthy individuals by ELISA. Quantification of LG3 confirmed a significant decrease in the urine of IgAN patients compared to healthy controls, except in ten patients in whom LG3 was increased. These ten patients had a more severe disease with lower glomerular filtration rate values. We found a significant inverse correlation between LG3 levels and glomerular filtration rate in the 43 patients with IgAN, which was not observed in 65 patients with other glomerular diseases including membranous nephropathy (23), lupus nephropathy (13), focal segmental glomerulosclerosis (15), diabetic nephropathy (14), and six patients with nonglomerular diseases. Therefore, we suggest that the LG3 fragment of endorepellin could be associated with IgAN severity and might be related to pathogenesis of IgAN.
authors.affiliation: INSERM, UMR S 702, Paris, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Surin
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Sachon
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Rougier
authors.forename: Céline
authors.initials: C
authors.lastname: Steverlynck
authors.forename: Christelle
authors.initials: C
authors.lastname: Garreau
authors.forename: Brigitte
authors.initials: B
authors.lastname: Lelongt
authors.forename: Pierre
authors.initials: P
authors.lastname: Ronco
authors.forename: Rémi
authors.initials: R
authors.lastname: Piedagnel
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine*; D003928:Diabetic Nephropathies / Q000652:urine; D003937:Diagnosis, Differential; D005260:Female; D005922:Glomerulonephritis, IGA / Q000175:diagnosis / Q000503:physiopathology / Q000652:urine; D015433:Glomerulonephritis, Membranous / Q000652:urine; D005923:Glomerulosclerosis, Focal Segmental / Q000652:urine; D019812:Heparan Sulfate Proteoglycans / Q000652:urine; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000652:urine; D011379:Prognosis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D015415:Biomarkers; D019812:Heparan Sulfate Proteoglycans; D010446:Peptide Fragments; C071927:perlecan