title: The impact of C4d-negative acute antibody-mediated rejection on short-term prognosis among kidney transplant recipients.
abstract: OBJECTIVE
  We aimed to investigate the clinical and pathological features of C4d-negative acute antibody-mediated rejection (aAMR), and examined the impact of C4d-negative aAMR on short-term prognosis.
  
  
  METHODS
  From 2005 to 2011, 626 kidney transplantations were performed in our institution and related hospitals. We excluded 174 ABO-incompatible transplantations, and analysed clinical and pathological data from the remaining 452 until December 2013.
  
  
  RESULTS
  During the follow-up period, 39 patients underwent aAMR. We divided them into two groups. According to C4d positivity in each patient's first AMR, we divided the cohort into a C4d-positive aAMR group and a C4d-negative aAMR group, using the new Banff 2013 classification. We compared each aAMR patient's features to controls. Clinical and pathological characteristics were similar in both groups and the short-term outcomes of the two groups were similar, but both were worse than control.
  
  
  CONCLUSIONS
  C4d-negative aAMR resembles C4d-positive aAMR in terms of clinical and pathological features, and that C4d positivity has no influence on short-term outcome.
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Sai
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Omoto
authors.affiliation: Department of Transplant Surgery, Toda Central General Hospital, Saitama, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Pathology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazuho
authors.initials: K
authors.lastname: Honda
authors.affiliation: Department of Urology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tanabe
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D015935:Complement C4b / Q000032:analysis*; D005260:Female; D006084:Graft Rejection / Q000145:classification / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007518:Isoantibodies / Q000032:analysis*; D007668:Kidney / Q000276:immunology* / Q000473:pathology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007518:Isoantibodies; D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d
keywords: C4d-negative; antibody-mediated rejection; kidney transplant