title: Relationship among C1q-fixing de novo donor specific antibodies, C4d deposition and renal outcome in transplant glomerulopathy.
abstract: BACKGROUND
  The C1q-binding properties of donor specific antibodies (DSA) may be related to antibody-mediated rejection and poor outcome.
  
  
  METHODS
  We retrospectively studied 35 kidney transplant recipients with transplant glomerulopathy (TG) and de novo DSA (dnDSA). C1q dnDSA were measured in the serum stored at renal biopsy and the association among C1q-fixing dnDSA, C4d deposition and graft loss was examined.
  
  
  RESULTS
  Of the 35 patients with dnDSA and TG, 15 (42.9%) had C1q-positive dnDSA and 20 (57.1%) had C1q-negative dnDSA. Ten out of 15 patients with C1q-positive dnDSA (66.6%) and 5 with C1q-negative dnDSA (25%) had C4d positive staining renal biopsies (P=0.02), being the C1q-negative dnDSA/C4d-negative TG 42.9% of the total. The C1q-positive dnDSA group has significantly higher IgG DSA Class II MFI than the C1q-negative dnDSA group (P=0.004). Patients with C4d deposits have significantly higher IgG DSA MFI for both Class I and Class II than those without C4d deposits (P=0.02). We found a trend toward higher graft loss in the C1q-positive dnDSA group (60%) versus the C1q-negative dnDSA group (40%) without a statistical significance (P=0.31).
  
  
  CONCLUSIONS
  Our study provides further characterization of TG associated with dnDSA. The major part of dnDSA-associated TG was C1q-negative and the presence of C1q-fixing dnDSA did not significantly correlate with graft outcome.
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Messina
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Ariaudo
authors.affiliation: Immunogenetics and Transplant Biology Service, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Loredana
authors.initials: L
authors.lastname: Praticò Barbato
authors.affiliation: Center for Experimental Medical Research (CeRMS), University of Turin, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Beltramo
authors.affiliation: Division of Pathology Transplantation, Department of Medical Sciences, University of Turin, Italy.
authors.forename: Gianna
authors.initials: G
authors.lastname: Mazzucco
authors.affiliation: Immunogenetics and Transplant Biology Service, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Amoroso
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ranghino
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy; Center for Experimental Medical Research (CeRMS), University of Turin, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cantaluppi
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fop
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy.
authors.forename: Giuseppe Paolo
authors.initials: GP
authors.lastname: Segoloni
authors.affiliation: Renal Transplantation Unit 'A. Vercellone', Division of Nephrology Dialysis and Transplantation, AOU Città della Salute e della Scienza di Torino and Department of Medical Sciences, University of Turin, Italy; Center for Experimental Medical Research (CeRMS), University of Turin, Italy. Electronic address: luigi.biancone@unito.it.
authors.forename: Luigi
authors.initials: L
authors.lastname: Biancone
mesh_terms: D000328:Adult; D000368:Aged; D015922:Complement C1q / Q000276:immunology*; D003181:Complement C4 / Q000276:immunology*; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000276:immunology* / Q000473:pathology; D006084:Graft Rejection / Q000276:immunology / Q000473:pathology; D006801:Humans; D007518:Isoantibodies / Q000276:immunology*; D007668:Kidney / Q000276:immunology* / Q000473:pathology; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003181:Complement C4; D007518:Isoantibodies; D015922:Complement C1q
keywords: Antibody mediated rejection; Complement; Donor specific antibodies; Kidney transplantation; Transplant glomerulopathy