title: Repeat true surveillance biopsies in kidney transplantation.
abstract: BACKGROUND
  Protocol biopsies are assigned to fixed points in time after transplantation irrespective of renal function. Usually, it is not known whether there is graft dysfunction at the time of biopsy. This study analyzes repeat protocol biopsies in the absence of any clinical signs of graft dysfunction at the time of biopsy (i.e., "true surveillance biopsy").
  
  
  METHODS
  Observational single center study. Kidney transplant recipients with protocol biopsies after 3 and 6 months were analyzed.
  
  
  RESULTS
  Three hundred seventy patients had protocol biopsies after 3 and 6 months. One hundred forty-eight patients (40%; 296 biopsies) with a median follow-up of 3.4 years (range, 0.95-7.7 years), fulfilled the criteria of repeat true surveillance biopsies. Graft survival censored for death was 100% at 1 year, 96% at the end of follow-up. One hundred eighty-four biopsies (62%) revealed pathological findings, mainly subclinical rejection (3/6 months: 41% vs. 45%; P = 0.2) and chronic lesions (3/6 months: 22% vs. 44%; P<0.001). Grafts with repeat pathological findings at 3 and 6 months had a significant decline in graft function at end of follow-up compared with grafts with no or only singular pathology (median delta estimated glomerular filtration rate: -10.24 vs. -0.19; P = 0.005). Ninety-three of 148 patients (63%) had a therapeutic intervention as a consequence of the biopsy.
  
  
  CONCLUSIONS
  Less than 50% of protocol biopsies were performed in the absence of any clinical signs of graft dysfunction. A high proportion of these biopsies revealed pathological findings that were associated with a significant decrease in long-term graft function.
authors.affiliation: Clinic for Transplantation Immunology and Nephrology, University Hospital Basel, Basel, Switzerland.
authors.forename: Thomas N
authors.initials: TN
authors.lastname: Buchmann
authors.forename: Thomas
authors.initials: T
authors.lastname: Wolff
authors.forename: Alexander
authors.initials: A
authors.lastname: Bachmann
authors.forename: Lorenz
authors.initials: L
authors.lastname: Guerke
authors.forename: Juerg
authors.initials: J
authors.lastname: Steiger
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mihatsch
authors.forename: Michael
authors.initials: M
authors.lastname: Dickenmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000473:pathology* / Q000503:physiopathology; D006085:Graft Survival; D006801:Humans; D016030:Kidney Transplantation / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult