title: Positive C4d in kidney transplantation biopsy: clinical impact.
abstract: BACKGROUND
  Deposition of C4d in peritubular capillaries of renal graft is normally associated with the presence of antibody-mediated rejection. The clinical impact of its presence in patients with renal transplant in Colombia is uncertain, as well as the association in acute rejection and the response to the management and survival of the graft. The aim of this study was to determine the risk of having positive C4d in biopsies of patients with episodes of acute cellular rejection.
  
  
  METHODS
  We retrospectively reviewed 226 biopsies of kidney transplantation, all of them with acute rejection and histopathological findings classified according to Banff criteria 2009 and performed between January 2005 and December 2012 for graft dysfunction. C4d staining was performed by immunohistochemistry.
  
  
  RESULTS
  C4d staining was positive in 25 of 226 biopsies. Rejection time in patients with positive C4d was 15 months in average vs 8 months with negative C4d.
  
  
  CONCLUSIONS
  With the use of a multivariate analysis, we found that the unique risk for C4d in our population was the positive panel reactive antibodies and elapsed time between transplant and the rejection (odds ratio: 2.12, P = .034) and that the other variables analyzed are not related to the expression of C4d.
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia. Electronic address: npedraza@colombianadetrasplantes.com.
authors.forename: N
authors.initials: N
authors.lastname: Pedraza
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia.
authors.forename: F
authors.initials: F
authors.lastname: Girón
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia.
authors.forename: Y
authors.initials: Y
authors.lastname: Baez
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia.
authors.forename: A
authors.initials: A
authors.lastname: Niño
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia.
authors.forename: J
authors.initials: J
authors.lastname: Rodriguez
authors.affiliation: Colombiana de Trasplantes, Departament: Kidney Transplant Service, Bogotá, Colombia.
authors.forename: C
authors.initials: C
authors.lastname: Orozco
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001706:Biopsy; D003105:Colombia; D015935:Complement C4b / Q000378:metabolism*; D005260:Female; D006084:Graft Rejection / Q000276:immunology* / Q000473:pathology; D006085:Graft Survival / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000276:immunology / Q000473:pathology*; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d