title: Kidney injury molecule-1 correlates with kidney function in renal allograft recipients.
abstract: BACKGROUND
  KIM-1 (kidney injury molecule-1) is responsible for the clearance of debris from damaged renal tubules. KIM-1 can be expressed and excreted in urine within 12 hours after the initial ischemic insult and before regeneration of the epithelium, persisting over time thereafter. Urinary KIM-1 has been reported to be a noninvasive, rapid, sensitive, and reproducible biomarker of experimental nephrotoxic and ischemic acute kidney injury. Renal KIM-1 expression is significantly increased in human kidney tissue among patients with a wide range of kidney diseases, including various types of glomerulonephritis, chronic allograft nephropathy, acute rejection, hypertension, and Wegener's granulomatosis. Both renal and urinary KIM-1 correlate with kidney damage and negatively with renal function, but not with proteinuria. The aim of this study was to assess whether urinary KIM-1 correlated with kidney function in kidney allograft recipients.
  
  
  METHODS
  Serum NGAL, creatinine and estimated glomerular filtration rate (eGFR) were evaluated in 170 kidney allograft recipients on therapy with a calcineurin inhibitor plus mycophenolate mofetil or azathioprine and prednisone as well as in healthy volunteers. KIM-1 was estimated in urine using a commercially available kit.
  
  
  RESULTS
  Kidney transplant recipients showed significantly higher KIM-1 values than the control group. Normotensive kidney allograft recipients displayed significantly lower NGAL results than hypertensive subjects. Urinary KIM-1 was significantly higher among diabetic than nondiabetic subjects, whereas creatinine did not differ significantly between them. Upon univariate analysis urinary KIM-1 strongly correlated with serum creatinine (r = .64) and eGFR (r = -.71), and only weakly with other parameters. Upon multiple regression analysis, the best predictor of urinary KIM-1 was eGFR (beta -0.61), which explained 61% of KIM-1 concentrations.
  
  
  CONCLUSIONS
  Even a successful kidney transplantation is associated with kidney injury as reflected by elevated urinary KIM-1 and lower eGFR. Therefore, KIM-1 needs to be investigated as a potential early marker for impaired renal function/kidney injury, especially in patients with other risk factors for damage such as hypertension or diabetes.
authors.affiliation: Department of Nephrology and Transplantology, Medical University, Bialystok, Poland. jolmal@poczta.onet.pl
authors.forename: J
authors.initials: J
authors.lastname: Malyszko
authors.forename: E
authors.initials: E
authors.lastname: Koc-Zorawska
authors.forename: J S
authors.initials: JS
authors.lastname: Malyszko
authors.forename: M
authors.initials: M
authors.lastname: Mysliwiec
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000503:physiopathology*; D016030:Kidney Transplantation; D008297:Male; D008562:Membrane Glycoproteins / Q000502:physiology*; D008875:Middle Aged; D011991:Receptors, Virus / Q000502:physiology*; D014184:Transplantation, Homologous; D055815:Young Adult
chemical_list: C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D011991:Receptors, Virus; D003404:Creatinine