title: Utility of serum creatinine/cystatin C ratio in diagnosis of postrenal acute kidney injury.
abstract: BACKGROUND
  In obstructive uropathy, despite a severe increase in the serum creatinine (Cr) levels, only a mild cystatin C (CysC) increase was previously reported. Therefore, we aimed to determine the availability of serum Cr/CysC ratio in predicting postrenal acute kidney injury (AKI).
  
  
  METHODS
  This was a cross-sectional study involving 61-adult patients with heterogeneous AKI cases. Patients with bilateral pelvicalyceal dilatation in renal sonography were considered as postrenal AKI group (n = 15) and others were intrinsic AKI group (n = 46). Venous blood sampling for blood urea nitrogen, Cr and CysC measurements were performed on admission.
  
  
  RESULTS
  The mean age of study population was 66.3 ± 15.5 years; 38 (62%) of which were male. Two groups were similar regarding age, gender, and comorbidities. Cr/CysC ratio was significantly higher in postrenal AKI group (6.9 ± 3.1 vs. 4.4 ± 2.1, P = 0.007).
  
  
  CONCLUSIONS
  We suggest that serum Cr/CysC ratio seems to be a useful diagnostic tool for detection of postrenal AKI cases, especially for the cases without definite hydronephrosis.
authors: Department of Internal Medicine, Division of Nephrology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Salih
authors: S
authors: İnal
authors: Department of Internal Medicine, Division of Nephrology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Atila
authors: A
authors: Altuntaş
authors: Department of Internal Medicine, Division of Nephrology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Veysel
authors: V
authors: Kidir
authors: Department of Urology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Alper
authors: A
authors: Özorak
authors: Department of Internal Medicine, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Yusuf
authors: Y
authors: İlgin
authors: Department of Internal Medicine, Division of Nephrology, Suleyman Demirel University Faculty of Medicine, Isparta, Turkey.
authors: Mehmet Tugrul
authors: MT
authors: Sezer
keywords: Acute kidney injury; creatinine/cystatin C ratio; cystatin C; obstructive uropathy; postrenal acute kidney injury
references: J Am Soc Nephrol. 2004 Jun;15(6):1597-605
references: 15153571
references: Clin Chem. 2007 Mar;53(3):480-8
references: 17259236
references: Crit Care. 2007;11(2):R31
references: 17331245
references: Kidney Int. 2008 Oct;74(8):1059-69
references: 18650797
references: Intensive Care Med. 2012 Jan;38(1):170-1
references: 21965103
references: Clin Chem. 2001 Nov;47(11):2055-9
references: 11673383
references: Clin Rheumatol. 2011 May;30(5):601-5
references: 20957401
references: Kidney Int. 2004 Sep;66(3):1115-22
references: 15327406
references: Kidney Int. 2003 May;63(5):1944-7
references: 12675875
references: Clin Chem. 2003 Apr;49(4):680-1
references: 12651831
references: Crit Care. 2005 Apr;9(2):R139-43
references: 15774046
references: Clin Exp Nephrol. 2010 Dec;14(6):608-13
references: 20607577
references: Scand J Clin Lab Invest. 1999 Dec;59(8):587-92
references: 10691049
references: Clin Exp Nephrol. 2009 Dec;13(6):567-70
references: 19536607
references: Ann Clin Biochem. 2000 Jan;37 ( Pt 1):49-59
references: 10672373
references: JAMA. 1996 May 15;275(19):1489-94
references: 8622223
references: Intensive Care Med. 2011 Mar;37(3):493-501
references: 21153403
references: Crit Care Med. 2002 Sep;30(9):2051-8
references: 12352040
references: Intensive Care Med. 1991;17(7):387-91
references: 1774391
references: N Engl J Med. 2007 Aug 23;357(8):797-805
references: 17715412
references: Rinsho Byori. 2008 Feb;56(2):101-7
references: 18404824
references: Scand J Clin Lab Invest. 1985 Apr;45(2):97-101
references: 3923607