title: Incidence of C4d stain in protocol biopsies from renal allografts: results from a multicenter trial.
abstract: C4d staining of renal allografts is regarded as an in situ marker of active humoral rejection. Few data are available about the incidence of C4d deposition in protocol biopsies compared to indication biopsies. To evaluate whether center-specific factors influence the incidence of C4d detection, we performed a multicenter study. From three European centers, 551 protocol and 377 indication biopsies were reclassified according to the updated Banff criteria and stained for C4d. C4d results were recorded as diffuse or focal positive and statistically correlated to clinical parameters, morphology and graft survival. In the protocol biopsies, a diffuse C4d stain was found in 2.0%, and a focal stain in 2.4%. In indication biopsies, 12.2% were diffusely and 8.5% focally C4d positive (protocol:indication p < 0.0001). The incidence of C4d deposition varied significantly between centers, attributable to variable numbers of presensitized patients with more C4d positive indication and protocol biopsies. Diffuse and focal C4d stain correlated with morphology of humoral rejection in protocol as well as in indication biopsies. Protocol biopsies show a significantly lower incidence of C4d deposition than indication biopsies. Subclinical C4d detection in protocol biopsies had no significant impact on allograft survival in our series.
authors.affiliation: Institut fuer Pathologie, Medizinische Hochschule Hannover, Germany. mengel.michael@mhhannover.de
authors.forename: Michael
authors.initials: M
authors.lastname: Mengel
authors.forename: Johannes
authors.initials: J
authors.lastname: Bogers
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bosmans
authors.forename: Daniel
authors.initials: D
authors.lastname: Serón
authors.forename: Francesc
authors.initials: F
authors.lastname: Moreso
authors.forename: Marta
authors.initials: M
authors.lastname: Carrera
authors.forename: Wilfried
authors.initials: W
authors.lastname: Gwinner
authors.forename: Anke
authors.initials: A
authors.lastname: Schwarz
authors.forename: Marc
authors.initials: M
authors.lastname: De Broe
authors.forename: Hans
authors.initials: H
authors.lastname: Kreipe
authors.forename: Hermann
authors.initials: H
authors.lastname: Haller
mesh_terms: D001706:Biopsy; D015935:Complement C4b / Q000378:metabolism*; D006084:Graft Rejection; D006085:Graft Survival; D006801:Humans; D016030:Kidney Transplantation / Q000379:methods / Q000473:pathology*; D015233:Models, Statistical; D015337:Multicenter Studies as Topic; D010446:Peptide Fragments / Q000378:metabolism*; D013194:Staining and Labeling
chemical_list: D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d