title: C4d staining in post-reperfusion renal biopsy is not useful for the early detection of antibody-mediated rejection when CDC crossmatching is negative.
abstract: BACKGROUND
  Sensitized patients (pts) may develop acute antibody-mediated rejection (AMR) due to preformed donor-specific antibodies, undetected by pre-transplant complement-dependent cytotoxicity (CDC) crossmatch (XM). We hypothesized that C4d staining in 1-h post-reperfusion biopsies (1-h Bx) could detect early complement activation in the renal allograft due to preformed donor-specific antibodies.
  
  
  METHODS
  To test this hypothesis, renal transplants (n = 229) performed between June 2005 and December 2007 were entered into a prospective study of 1-h Bx and stained for C4d by immunofluorescence. Transplants were performed against a negative T-cell CDC-XM with the exception of three cases with a positive B-cell XM.
  
  
  RESULTS
  All 229 1-h Bx stained negative for C4d. Fourteen pts (6%) developed AMR. None of the 14 protocol 1-h Bx stained positive for C4d in peritubular capillaries (PTC). However, all indication biopsies-that diagnosed AMR-performed at a median of 8 days after transplantation stained for C4d in PTC.
  
  
  CONCLUSIONS
  These data show that C4d staining in 1-h Bx is, in general, not useful for the early detection of AMR when CDC-XM is negative.
authors.affiliation: Renal Transplantation Service of the Urology Division, School of Medicine, Sao Paulo University, Brazil. elias.david.neto@attglobal.net
authors.forename: Elias
authors.initials: E
authors.lastname: David-Neto
authors.forename: Daisa S R
authors.initials: DS
authors.lastname: David
authors.forename: Giordano F
authors.initials: GF
authors.lastname: Ginani
authors.forename: Helcio
authors.initials: H
authors.lastname: Rodrigues
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Souza
authors.forename: Maria Cristina R
authors.initials: MC
authors.lastname: Castro
authors.forename: Hideki
authors.initials: H
authors.lastname: Kanashiro
authors.forename: Fernando
authors.initials: F
authors.lastname: Saito
authors.forename: Renato
authors.initials: R
authors.lastname: Falci
authors.forename: Ioannis M
authors.initials: IM
authors.lastname: Antonopoulos
authors.forename: Afonso Celso
authors.initials: AC
authors.lastname: Piovesan
authors.forename: William C
authors.initials: WC
authors.lastname: Nahas
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D015935:Complement C4b / Q000276:immunology* / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D005260:Female; D006084:Graft Rejection / Q000209:etiology / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007518:Isoantibodies / Q000276:immunology*; D007668:Kidney / Q000473:pathology / Q000601:surgery; D007674:Kidney Diseases / Q000150:complications / Q000628:therapy; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism; D011446:Prospective Studies; D015424:Reperfusion
chemical_list: D007518:Isoantibodies; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d