title: Single center experience of subclinical rejections and BK nephropathies by kidney allografts' surveillance biopsies.
abstract: OBJECTIVE
  Acute rejection of the kidney allograft remains the most important factor affecting the long-term graft outcome and is a major predictor of development of chronic damage and graft loss. Several studies have shown that early detection and treatment of subclinical rejection episodes may be beneficial for the graft outcome. The role of protocol (surveillance) biopsies and the value of donor specific antibodies (DSA) monitoring are still debatable.
  
  
  METHODS
  This is a prospective observational study involving seventeen kidney recipients transplanted in north-eastern part of Poland who underwent "zero", 3-month and 12-month allograft biopsies as well as DSA assessment.
  
  
  RESULTS
  Histologic analysis of the biopsies showed subclinical acute cellular rejection in 17.6% of patients (two tubulointerstitial, one vascular) at 3-months post transplantation, and additional case of borderline rejection at the 12-month point. Moreover, two cases (11.8%) of polyomavirus BK nephropathy were diagnosed (one at 3 and one at 12 month point). None of the patients developed de novo DSA.
  
  
  CONCLUSIONS
  Our protocol biopsies allowed us to detect significant proportion of patients with subclinical, but histologically relevant acute cellular rejection and BK nephropathy. Early therapeutic intervention had beneficial effects in a 4-year follow up.
authors.affiliation: 1st Department of Nephrology and Transplantation with Dialysis Unit, Medical University of Bialystok, Bialystok, Poland. Electronic address: bnaumnik@poczta.onet.pl.
authors.forename: Beata
authors.initials: B
authors.lastname: Naumnik
authors.affiliation: Department of Medical Pathology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kowalewska
authors.affiliation: 1st Department of Nephrology and Transplantation with Dialysis Unit, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Hryszko
authors.affiliation: Department of Vascular Surgery and Transplantology, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Glowiński
authors.affiliation: Department of Transplantation Medicine and Nephrology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Durlik
authors.affiliation: 1st Department of Nephrology and Transplantation with Dialysis Unit, Medical University of Bialystok, Bialystok, Poland.
authors.forename: Michal C
authors.initials: MC
authors.lastname: Myśliwiec
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D064591:Allografts; D001739:BK Virus / Q000472:pathogenicity*; D001706:Biopsy; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000209:etiology*; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology*; D007676:Kidney Failure, Chronic / Q000473:pathology / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D027601:Polyomavirus Infections / Q000209:etiology*; D011159:Population Surveillance; D011379:Prognosis; D011446:Prospective Studies
keywords: BKV nephropathy; Kidney transplantation; Subclinical rejection; Surveillance biopsy