title: Risk factors for Banff borderline acute rejection in protocol biopsies and effect on renal graft function.
abstract: BACKGROUND
  The interpretation and handling of Banff borderline acute rejection observed in protocol biopsies from patients with stable renal function continues to be controversial. Our objective was to identify the risk factors for borderline acute rejection on 1-year protocol biopsies and to evaluate their effect on renal graft function after 2 years' follow-up.
  
  
  METHODS
  We included 82 kidney transplant recipients (KTR), who underwent 1-year protocol biopsies with normal or stable graft function. All KTR had follow-up of at least 2 years posttransplantation. We formed three groups: (1) KTR with a normal biopsy, (2) KTR with borderline changes, and (3) KTR with interstitial fibrosis/tubular atrophy (IF/TA). We searched for risk factors related to borderline injury. The main outcome to evaluate was renal function at 1 month, at protocol biopsy, and 2 years posttransplant.
  
  
  RESULTS
  The 82 patients included in this study showed no differences in immunosuppression, gender, etiology of renal failure, or percentage of panel-reactive antibodies. The risk factors associated with borderline lesions were: at least one biopsy due to allograft dysfunction and acute rejection events during the first year posttransplant (P = .011 and P = .021, respectively). Increased serum creatinine and estimated glomerular filtration rate decline were greater among the borderline lesion than the normal group, but similar to patients with IF/TA.
  
  
  CONCLUSIONS
  Renal function decline was greater among borderline and IF/TA groups. However, the sum of insults, and not only the borderline injury itself, produces greater declines in renal function with greater risk for graft loss.
authors.affiliation: Department of Nephrology and Mineral Metabolism, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Mexico City, DF, Mexico.
authors.forename: E H
authors.initials: EH
authors.lastname: Espinoza
authors.forename: C
authors.initials: C
authors.lastname: González-Parra
authors.forename: D M
authors.initials: DM
authors.lastname: Macías-Díaz
authors.forename: N O
authors.initials: NO
authors.lastname: Uribe-Uribe
authors.forename: J
authors.initials: J
authors.lastname: Alberú
authors.forename: L E
authors.initials: LE
authors.lastname: Morales-Buenrostro
mesh_terms: D000208:Acute Disease; D001284:Atrophy; D001706:Biopsy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000453:epidemiology / Q000473:pathology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation / Q000276:immunology / Q000473:pathology* / Q000502:physiology; D008297:Male; D012307:Risk Factors; D013997:Time Factors
chemical_list: D006680:HLA Antigens