Cystatin C,Serum

Cystatin C, Serum

Test Name: Cystatin C, Serum

Sample Type: Serum
Method: Immunoassay / Particle-enhanced immunoturbidimetric assay (method may vary by laboratory)

What is the Cystatin C Test?

Cystatin C is a small protein produced by almost all nucleated cells and filtered by the kidneys. Measuring Cystatin C in blood helps assess kidney filtration and can be used to estimate the glomerular filtration rate (eGFR).

Why is this test done?

• To assess kidney function
• To detect early reduction in kidney filtration
• To help estimate eGFR
• To monitor patients with known kidney disease
• When creatinine-based kidney assessment may be less reliable

Clinical Significance

Cystatin C levels generally increase when kidney filtration decreases. It may detect changes in kidney function earlier than serum creatinine in some situations.

Sample Required

Serum – blood sample

Patient Preparation

Usually no special preparation is required, unless advised otherwise by the healthcare provider.

Important Note

Cystatin C results should be interpreted along with serum creatinine, eGFR, clinical history, and other kidney function tests. Reference ranges may vary between laboratories.