cystatin C


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cystatin C

(sĭs′tăt-ĭn)
A cysteine proteinase inhibitor found in the bloodstream in elevated concentrations in patients with impaired kidney function. It is a small protein composed of 120 amino acids (mass 13 kD) that is produced by nucleated cells throughout the body and easily filtered by the glomeruli of the kidneys. It is reabsorbed and catabolized by proximal tubular cells. Because levels of cystatin C do not depend on a patient's age, height, muscle mass, or weight, it is thought to be a better measure of kidney function than the creatinine clearance test, which is most often used to assess renal health.
References in periodicals archive ?
Objective: To compare e-GFR estimated by creatinine or cystatin C based and combined creatinine and cystatin C based equations in type 2 diabetics in different stages of albuminuria.
A blood test of kidney function known as cystatin C has been shown to be an alternative, better marker of creatinine, compared with GFR, and is supported by the Kidney Disease: Improving Global Outcomes CKD work group's 2012 clinical practice guidelines for the evaluation and management of CKD.
Today, there are three primary measured biomarkers used in CKD diagnosis and management: creatinine, urine albumin (UAlb), and cystatin C.
The previous studies have suggested that serum cystatin C concentration is a better indicator of GFR than the serum creatinine concentration in patients with spine injury, liver cirrhosis, diabetes, mild-to-moderate impaired kidney function and in elderly patients.
We would like to comment on the article "Performance in Measurement of Serum Cystatin C by Laboratories Participating in the College of American Pathologists 2014 CYS Survey" reporting substantial method-specific biases for cystatin C measurements.
The major inhibitor of cathepsin S in extracellular fluids including plasma is cystatin C which is expressed by alveolar macrophages, bronchioepithelial cells, and endothelial cells [10-12].
It is produced by all nucleated cells and freely filtered by the glomerular membrane, entirely catabolized by proximal tubule, without secretion, and serum concentration of cystatin C is determined by GFR.
Aims and Objectives: To evaluate serum cystatin C and its correlation with biochemical, clinical, and anthropometric parameters in patients with type 2 diabetes and healthy controls.
Cystatin C is a 13-kDa cysteine protease inhibitor produced at a constant rate by most nucleated cells.