Cystatin C

Cystatin C is a protein produced by all nucleated cells that is filtered by the kidneys. It is used as an alternative to creatinine for estimating kidney function.

Category: Kidney Function

Also known as: cystatin c, cystatin-c, cys c, serum cystatin c

Reference range: 0.62–1.15 mg/L (Source: ABIM)

Standard unit: mg/L

High values may indicate

High cystatin C levels may indicate decreased kidney function, chronic kidney disease, or acute kidney injury.

Low values may indicate

Low cystatin C levels are uncommon and generally not clinically significant, though they may be seen with hyperthyroidism or corticosteroid use.

Source: MedlinePlus, U.S. National Library of Medicine

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