Cystatin C (Quantitative)

The cystatin-C quantitative serum test measures the level of cystatin-C, a protein produced by all nucleated cells in the body. It serves as a reliable marker for assessing kidney function, particularly glomerular filtration rate (GFR), and is often used as an alternative to creatinine-based tests.

The test is recommended for patients with chronic kidney disease (CKD), diabetes, hypertension, or other conditions that may affect kidney function. It is particularly useful for patients in whom creatinine-based tests may be unreliable, such as the elderly, obese, or those with reduced muscle mass.

A blood sample is collected, and cystatin-C levels are quantified using immunoassay techniques. The results help estimate GFR and evaluate kidney function more accurately, especially in early stages of kidney dysfunction.

Cystatin-C provides a more sensitive and accurate measure of kidney function, particularly in detecting mild to moderate renal impairment. Unlike creatinine, cystatin-C levels are less affected by muscle mass, age, and gender, making it a preferred marker in certain clinical situations.

Elevated cystatin-C levels suggest reduced kidney function or impaired GFR. Consistently high levels may indicate the presence of chronic kidney disease (CKD) or other conditions affecting the kidneys, warranting further evaluation and management.