title: In kidney transplant recipients with BK polyomavirus infection, early BK nephropathy, microvascular inflammation, and serum creatinine are risk factors for graft loss.
abstract: BACKGROUND
  Little information is available on the risk factors for graft loss in kidney transplant recipients with BK polyomavirus (BKPyV) nephropathy (BKVN) in the presence or absence of antibody-mediated rejection (AMR).
  
  
  METHODS
  We examined the risk factors for graft loss in consecutive kidney allograft recipients with biopsy-confirmed BKVN, with or without concomitant AMR.
  
  
  RESULTS
  A total of 1904 kidney transplants were performed at our institution during 2005-2011. Of these, 330 (17.33%) were diagnosed with BKPyV viremia, and 69 were diagnosed with BKVN (3.6%). Eleven patients had a concomitant diagnosis of AMR. Patients with AMR were characterized by significantly higher peak panel-reactive antibody, retransplant rates, and desensitization preconditioning at the time of transplantation, as well as microvascular inflammation (MVI = glomerulitis + peritubular capillaritis), C4d score, and donor-specific antibody at the time of diagnosis (P ≤ 0.01). Treatment with plasma exchange, intravenous immunoglobulin, and cidofovir was more prevalent in this group (P ≤ 0.02). Univariate analyses assessing the risk factors for graft loss in all patients with BKVN, identified an independent association of African-American race, deceased-donor transplantation, serum creatinine (Scr), MVI, and early disease (BKVN within 6 months of transplant) with poor outcomes. Multivariate analyses retained only 3 variables: Scr >2 mg/dL (hazard ratio [HR] = 4.3, 95% confidence interval [CI] 1.9-9.7, P = 0.0004), early BKVN (HR = 2.7, 95% CI 1.3-5.3, P = 0.004), and MVI (HR = 1.8, 95% CI 1.2-2.8, P = 0.008).
  
  
  CONCLUSIONS
  These observations suggest that, in patients with BK infection, early BKVN, Scr >2, and MVI are predictors of poor outcomes. Further studies are needed to determine effective treatment strategies for BKVN, with or without AMR.
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: M
authors.initials: M
authors.lastname: Mohamed
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: S
authors.initials: S
authors.lastname: Parajuli
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: B
authors.initials: B
authors.lastname: Muth
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Astor
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Panzer
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: D
authors.initials: D
authors.lastname: Mandelbrot
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: W
authors.initials: W
authors.lastname: Zhong
authors.affiliation: Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: A
authors.initials: A
authors.lastname: Djamali
mesh_terms: D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use; D001739:BK Virus / Q000235:genetics / Q000302:isolation & purification*; D000077404:Cidofovir; D003404:Creatinine / Q000097:blood; D003596:Cytosine / Q000031:analogs & derivatives / Q000627:therapeutic use; D005260:Female; D006084:Graft Rejection / Q000517:prevention & control*; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D007166:Immunosuppressive Agents / Q000009:adverse effects; D007668:Kidney / Q000473:pathology / Q000601:surgery / Q000821:virology; D007674:Kidney Diseases / Q000453:epidemiology* / Q000601:surgery / Q000821:virology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D063065:Organophosphonates / Q000627:therapeutic use; D010951:Plasma Exchange; D027601:Polyomavirus Infections / Q000453:epidemiology* / Q000821:virology; D011379:Prognosis; D012307:Risk Factors; D014412:Tumor Virus Infections / Q000453:epidemiology* / Q000821:virology; D014766:Viremia
chemical_list: D000998:Antiviral Agents; D016756:Immunoglobulins, Intravenous; D007166:Immunosuppressive Agents; D063065:Organophosphonates; D003596:Cytosine; D003404:Creatinine; D000077404:Cidofovir
keywords: BK nephropathy; BK virus; kidney transplantation; risk factors