Cystatin urinary biomarkers

Finn WF, Porter GA (1998) Urinary biomarkers and nephrotoxicity. In DeBroe ME, Porter GA, Bennett WM, Verpooten GA (eds) Clinical Nephrotoxins. Kluwer Academic Publishers, Dordrecht, Netherlands, pp 61-99 Finney H, Newman DJ, Gruber W, Merle P, Price CP (1997) Initial evaluation of cystatin C measurement by particle-enhanced immunonephelometry on the Behring nephelemeter systems (BNA, BN II). Clin Chem 43 1016-1022... 

Cystatin C is nearly completely metabolized by proximal renal tubular cells. As a consequence, under ordinary circumstances there is little to no detectable cystatin C present in the urine. Thus, a true clearance of cystatin C cannot be determined. However, in the presence of tubular damage, cystatin C may be detected in the urine [147,148] and may be more sensitive to early and mild changes of kidney function compared with creatinine [149,150]. In this regard, elevation in serum cystatin C consistent with AKI, defined by at least a 50% increase from baseline, was evident 1-2 days prior to changes in SCr [151]. Finally, in patients with AKI, elevated urinary cystatin C was highly predictive of subsequent need for acute renal replacement therapy and outperformed several other urinary biomarkers in some studies [152]., but not in others [152a]... 

Flerget-Rosenthal S, van Wijk JA, Brocker-Preuss M, Bokenkamp A. Increased urinary cystatin C reflects structural and functional renal tubular impairment independent of glomerular filtration rate. Clin Biochem 2007 27 April [Epub ahead of print].This study provides evidence for urinary cystatin C as a biomarker for tubular injury. 

Togashi Y, Sakaguchi Y, Miyamoto M, Miyamoto Y. (2012) Urinary cystatin C as a biomarker for acute kidney injury and its immunohistochemical localization in kidney in the CDDP-treated rats. Exp Toxicol Pathol. 64 797-805. 

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