title: Decreased Kidney Graft Survival in Low Immunological Risk Patients Showing Inflammation in Normal Protocol Biopsies.
abstract: BACKGROUND
  The pros and cons for implementing protocol biopsies (PB) after kidney transplantation are still a matter of debate. We aimed to address the frequency of pathological findings in PB, to analyze their impact on long-term graft survival (GS) and to analyze the risk factors predicting an abnormal histology.
  
  
  METHODS
  We analyzed 946 kidney PB obtained at a median time of 6.5 (±2.9) months after transplantation. Statistics included comparison between groups, Kaplan-Meier and multinomial logistic regression analysis.
  
  
  CONCLUSIONS
  PB diagnosis were: 53.4% normal; 46% IFTA; 12.3% borderline and 4.9% had subclinical acute rejection (SCAR). Inflammation had the strongest negative impact on GS. Therefore we split the cases into: "normal without inflammation", "normal with inflammation", "IFTA without inflammation", "IFTA with inflammation" and "rejection" (including SCAR and borderline). 15-year GS in PB diagnosed normal with inflammation was significantly decreased in a similar fashion as in rejection cases. Among normal biopsies, inflammation increased significantly the risk of 15-y graft loss (P = 0.01). Variables that predicted an abnormal biopsy were proteinuria, previous AR and DR-mismatch.
  
  
  CONCLUSIONS
  We conclude that inflammation in normal PB is associated with a significantly lower 15-y GS, comparable to rejection or IFTA with inflammation.
authors.affiliation: Helsinki University Hospital, Nephrology, Helsinki, Finland.
authors.forename: Fernanda
authors.identifier: http://orcid.org/0000-0003-0462-4833
authors.initials: F
authors.lastname: Ortiz
authors.affiliation: Bellvitge University Hospital, Department of Nephrology, Barcelona, Spain.
authors.forename: Rosana
authors.initials: R
authors.lastname: Gelpi
authors.affiliation: Helsinki University Hospital, Transplantation and liver surgery, Helsinki, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Helanterä
authors.affiliation: Bellvitge University Hospital, Department of Nephrology, Barcelona, Spain.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Melilli
authors.affiliation: Helsinki University Hospital, Nephrology, Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Honkanen
authors.affiliation: Bellvitge University Hospital, Department of Nephrology, Barcelona, Spain.
authors.forename: Oriol
authors.initials: O
authors.lastname: Bestard
authors.affiliation: Bellvitge University Hospital, Department of Nephrology, Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Grinyo
authors.affiliation: Bellvitge University Hospital, Department of Nephrology, Barcelona, Spain.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Cruzado
mesh_terms: D000328:Adult; D001706:Biopsy / Q000379:methods*; D005260:Female; D006084:Graft Rejection / Q000175:diagnosis* / Q000276:immunology; D006085:Graft Survival / Q000276:immunology; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007668:Kidney / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000175:diagnosis; D012189:Retrospective Studies