Test Code 1008
Test Details
Cystatin C
Cystatin C is a protein produced by all nucleated cells at a constant rate. It is the most reliable available serum marker of kidney function and is superior to creatinine in estimating glomerular filtration (eGFR) rate as it is much less affected by age, gender, muscle mass, and/or ethnic background.
Methodology
Immunoturbidimetric assay
Patient Preparation
None
Preferred Specimen
1.0 mL serum (0.5 mL minimum) collected in serum separator tube (Tiger Top)
Alternate Specimen
1.0 mL EDTA plasma (0.5 mL minimum) collected in plasma separator tube (Pearl Top)
Transport Temperature
Refrigerated (ship on frozen cold packs)
Stability
Refrigerated: 3 days
Lab Values
Cystatin C
- Normal: ≤1.20 mg/L
- High: >1.20 mg/L
Clinical Significance
Cystatin C
Cystatin C used to calculate estimating glomerular filtration rate (eGFR).
Treatment Options
Cystatin C
- Refer to Estimated Glomerular Filtration Rate (eGFR)/Cystatin C for treatment considerations.
