title: Identification and characterization of a new autoimmune protein in membranous nephropathy by immunoscreening of a renal cDNA library.
abstract: Membranous Nephropathy (MN) represents a large amount of Nephrotic Syndromes in the adult population and its definitive diagnosis is currently carried out through biopsy. An autoimmune condition has been demonstrated in idiopathic MN (iMN) in which some kidney structures are targeted by patient autoantibodies. Some candidate antigens have been described and other likely involved target proteins responsible for the disease are not known yet. In this work our aim is to identify these proteins by screening a lambda-phage library with patients' sera. We enrolled four groups of patients: two MN groups of 12 full iMN patients; one control group of 15 patients suffering from other renal diseases; one control group of 15 healthy individuals. A commercial cDNA phagemide library was screened using the above described sera, in order to detect positive signals due to antigen-antibody bond. We detected one phagemide clone expressing a protein which was shown to be targeted by the antibodies of the iMN sera only. Control sera were negative. The sequence analysis of cDNA matched the Synaptonemal Complex protein 65 (SC65) coding sequence. Further proteomic analyses were carried out to validate our results. We provide evidence of an involvement of SC65 protein as an autoimmune target in iMN. Considering the invasiveness and the resulting risk coming from renal biopsy, our ongoing aim is to set a procedure able to diagnose affected patients through a little- or non-invasive method such as blood sampling rather than biopsy.
authors.affiliation: Department of Medicines, Emergency Medicine and Medical Specialities, Division of Nephrology Dialysis and Renal Transplantation, University of Modena and Reggio Emilia, Modena, Italy. fabrizio.cavazzini@unimore.it
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Cavazzini
authors.forename: Riccardo
authors.initials: R
authors.lastname: Magistroni
authors.forename: Luciana
authors.initials: L
authors.lastname: Furci
authors.forename: Valentina
authors.initials: V
authors.lastname: Lupo
authors.forename: Giulia
authors.initials: G
authors.lastname: Ligabue
authors.forename: Maria
authors.initials: M
authors.lastname: Granito
authors.forename: Marco
authors.initials: M
authors.lastname: Leonelli
authors.forename: Alberto
authors.initials: A
authors.lastname: Albertazzi
authors.forename: Gianni
authors.initials: G
authors.lastname: Cappelli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000502:physiology; D001706:Biopsy; D015153:Blotting, Western; D018076:DNA, Complementary / Q000737:chemistry; D005260:Female; D005455:Fluorescent Antibody Technique; D015723:Gene Library; D015433:Glomerulonephritis, Membranous / Q000276:immunology*; D006801:Humans; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D013573:Synaptonemal Complex
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D018076:DNA, Complementary; C581197:P3H4 protein, human