title: Cystatin C: why clinical laboratories should be measuring it.
abstract: Cystatin C is a 13-kDa cysteine protease inhibitor that satisfies many of the criteria required of a marker of glomerular filtration rate. It can be readily measured in laboratories using automated, standardised immunoassays. Hitherto there has been reluctance to adopt cystatin C measurement in the assessment of kidney function, despite demonstrated superiority compared to the current standard of practice, serum creatinine. This may be due to increased direct reagent costs. Recent strong evidence has confirmed the superior ability of cystatin C compared to creatinine to predict risk of a range of poor outcomes (including kidney failure, cardiovascular events and mortality) among patients with chronic kidney disease. On the back of this, national and international guidelines including those of the National Institute for Health and Clinical Excellence have recommended the use of cystatin C to risk stratify individuals with mild to moderately reduced glomerular filtration rate and no albuminuria. Cystatin C presents an opportunity for laboratories to engage with their users in developing clinical pathways which will usefully focus chronic kidney disease management on those most likely to benefit while reassuring patients at low risk.
authors.affiliation: Clinical Biochemistry, East Kent Hospitals University NHS Foundation Trust, Canterbury, UK elamb@nhs.net.
authors.forename: Edmund J
authors.initials: EJ
authors.lastname: Lamb
mesh_terms: D001774:Blood Chemical Analysis; D055316:Cystatin C / Q000097:blood*; D005919:Glomerular Filtration Rate; D006801:Humans; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000503:physiopathology; D018570:Risk Assessment
chemical_list: D055316:Cystatin C
keywords: Creatinine; cystatin C; glomerular filtration rate; kidney disease; morbidity; mortality