title: BK virus-associated nephropathy: neutrophil gelatinase-associated lipocalin as a new diagnostic tool?
abstract: BACKGROUND
  BK nephropathy has emerged as an important cause for allograft failure in renal transplant patients. The kidney tubules are the main target of BK virus infiltration. Neutrophil gelatinase-associated lipocalin (NGAL) has been proven to be a powerful biomarker for tubular damage. Therefore, we investigated the suitability of plasma NGAL as new diagnostic tool in patients with BK infection.
  
  
  METHODS
  We retrospectively analyzed 240 renal transplant recipients. Systematic BKV screening by plasma PCR was performed one month after transplantation and every three month thereafter for two yr. Plasma NGAL concentration was investigated using a commercial ELISA. Medical records and electronic databases were reviewed for clinical parameters.
  
  
  RESULTS
  BK viremia (BKV+) was diagnosed in 5.0% (12/240) and BK nephropathy in 3.3% (8/240) of our patients. BKV+ patients received more induction therapy (p = 0.03) and experienced a higher rate of biopsy-proven rejections compared to 13 control patients with similar graft function but negative BKV PCR. Contrary to our hypothesis, there was no difference in plasma NGAL expression between both groups (128.6 vs. 172.2 ng/mL; p = 0.68).
  
  
  CONCLUSIONS
  Intensified immunosuppressive therapy is associated with an increased risk for BK nephropathy. Plasma NGAL is neither suitable for diagnosing BK nephropathy nor helpful in predicting the individual course of patients with BKV infection.
authors: Medizinische Klinik und Poliklinik IV, Nephrologisches Zentrum, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany. Simon.Rau@med.uni-muenchen.de
authors: Simon
authors: S
authors: Rau
authors: Ulf
authors: U
authors: Schönermarck
authors: Gundula
authors: G
authors: Jäger
authors: Manfred
authors: M
authors: Stangl
authors: Markus
authors: M
authors: Guba
authors: Bruno
authors: B
authors: Meiser
authors: Michael
authors: M
authors: Fischereder
authors: Antje
authors: A
authors: Habicht
mesh_terms: D000209:Acute-Phase Proteins; D000328:Adult; D001739:BK Virus; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D016030:Kidney Transplantation; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D027601:Polyomavirus Infections / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D011518:Proto-Oncogene Proteins / Q000097:blood*; D012189:Retrospective Studies; D014412:Tumor Virus Infections / Q000097:blood / Q000175:diagnosis* / Q000209:etiology
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins