title: Urine periostin as a biomarker of renal injury in chronic allograft nephropathy.
abstract: BACKGROUND
  Chronic allograft nephropathy (CAN) represents the main cause of renal allograft failure after transplantation. Noninvasive CAN testing is required. Periostin promotes the expression of a mesenchymal phenotype in renal tubules and is a promising urine biomarker for progressive renal injury. Information regarding periostin expression in the setting of CAN remains scarce.
  
  
  METHODS
  Subjects were recruited from our outpatient transplantation clinic. Random urine samples were collected from CAN patients (n = 24) and renal transplant patients with normal renal function (transplant controls, n = 18). Control samples were collected from healthy volunteers (n = 18) who had normal renal function. Urine periostin was measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  The median urine periostin in CAN patients was significantly higher than in transplant and healthy controls (1.74 vs 0.00 vs 0.14 ng/mg creatinine, respectively; P < .001). Urine periostin enzyme-linked immunosorbent assay at a cutoff value of 0.152 ng/mg creatinine demonstrated the sensitivity, specificity, and accuracy for distinguishing CAN patients from transplant patients with normal renal function (91.7%, 77.8%, and 85.7%, respectively). In addition, urine periostin levels correlated directly with urine protein creatinine ratio (R = 0.566, P < .001) and serum creatinine (R = 0.522; P < .001), whereas inverse significant correlations were evidenced with estimated glomerular filtration rate (R = -0.431; P < .001).
  
  
  CONCLUSIONS
  The appearance of urine periostin in CAN patients but not in healthy and transplant controls underscores its value as a potential biomarker for chronic progressive renal injury in transplant recipients.
authors: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand. Electronic address: satirapoj@yahoo.com.
authors: B
authors: B
authors: Satirapoj
authors: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors: R
authors: R
authors: Witoon
authors: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors: P
authors: P
authors: Ruangkanchanasetr
authors: Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok, Thailand.
authors: P
authors: P
authors: Wantanasiri
authors: Department of Pathology, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors: M
authors: M
authors: Charoenpitakchai
authors: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors: P
authors: P
authors: Choovichian
mesh_terms: D000328:Adult; D064591:Allografts; D015415:Biomarkers / Q000378:metabolism / Q000652:urine*; D015992:Body Mass Index; D016022:Case-Control Studies; D015815:Cell Adhesion Molecules / Q000652:urine*; D003404:Creatinine / Q000652:urine; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D006084:Graft Rejection / Q000276:immunology; D006085:Graft Survival; D006801:Humans; D007150:Immunohistochemistry; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000652:urine*; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009393:Nephritis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; C512835:POSTN protein, human; D003404:Creatinine