About Cystatin C Lab Test

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Cystatin C is a small protein produced by all the nucleated cells of the body and found in body fluids like blood. It is filtered by the glomeruli (tiny blood vessels) present in the kidney affecting its blood concentration and is evaluated by measuring the glomerular filtration rate (GFR is the rate at which kidneys filters the fluid). High or low glomerular filtration rate depends upon the functioning of the kidneys; low glomerular filtration rate may indicate disease related to kidney or its dysfunction.

Cystatin C acts as a sensitive marker for kidney related diseases. Since Cystatin C is filtered by the kidneys, its blood concentration is inversely proportional to GFR; meaning low GFR resulting in higher concentration of Cystatin C in blood. Whereas, high GFR results in a low concentration of blood Cystatin C levels.

Unlike creatinine, Cystatin C is not affected by age, diet, and body mass of an individual which may be beneficial for accurate assessment of GFR for old, obese or malnourished individuals. This test helps you in measuring the Cystatin C concentration in your blood.