title: Periostin as a tissue and urinary biomarker of renal injury in type 2 diabetes mellitus.
abstract: BACKGROUND
  Improving the early detection of diabetic nephropathy remains a great challenge in disease management. Periostin is a marker of renal tubular injury and related to progressive kidney injury in animal models of chronic kidney disease. The clinical implications of urinary periostin activities in patients with type 2 diabetes have not been evaluated.
  
  
  METHODS
  Urine samples were obtained from 30 healthy volunteers and 328 type 2 diabetic patients with normoalbuminuria (n=114), microalbuminuria (n=100) and macroalbuminuria (n=114). The excretion levels of urinary periostin were quantified with enzyme-linked immunosorbent assay. Immunohistochemical periostin expression was determined in kidney tissues from overt diabetic nephropathy.
  
  
  RESULTS
  Increased periostin expression in glomeruli and tubular epithelium in diabetic renal pathology was observed. Urinary periostin levels were significantly elevated in the patients of the normoalbuminuria [3.06 (IQR: 1.12, 6.77) ng/mgCr], microalbuminuria [8.71 (IQR: 5.09, 19.29) ng/mgCr] and macroalbuminuria [13.58 (IQR: 3.99, 16.19) ng/mgCr] compared with healthy controls [1.15 (IQR: 0.60, 1.63) ng/mgCr] (P<0.01).Increased urine periostin level significantly correlated with aging, high albuminuria and decline of GFR. Urine periostin ELISA also demonstrated high performance for the diagnosis of established normoalbuminuric, microalbuminuric and macroalbuminuric type 2 diabetes (AUC 0.78 (95%CI, 0.71 to 0.86), 0.99 (95%CI, 0.98 to 1.00) and 0.95 (95%CI, 0.91 to 0.98), respectively).
  
  
  CONCLUSIONS
  The study indicates that increased urine periostin levels can be detected in patients with type 2 diabetes before the onset of significant albuminuria. Urinary periostin is an associated renal derangement in patients with established diabetic nephropathy and it may be used as an early marker of diabetic renal injury.
authors.affiliation: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors.forename: Bancha
authors.initials: B
authors.lastname: Satirapoj
authors.affiliation: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors.forename: Surat
authors.initials: S
authors.lastname: Tassanasorn
authors.affiliation: Department of Pathology, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors.forename: Mongkon
authors.initials: M
authors.lastname: Charoenpitakchai
authors.affiliation: Division of Nephrology, Department of Medicine, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand.
authors.forename: Ouppatham
authors.initials: O
authors.lastname: Supasyndh
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000209:etiology / Q000473:pathology / Q000652:urine; D015415:Biomarkers / Q000032:analysis / Q000652:urine; D001706:Biopsy; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000652:urine*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000652:urine*; D003928:Diabetic Nephropathies / Q000175:diagnosis / Q000473:pathology / Q000652:urine*; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D007678:Kidney Glomerulus / Q000737:chemistry / Q000473:pathology; D007684:Kidney Tubules / Q000737:chemistry / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012494:Sampling Studies
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; C512835:POSTN protein, human