Test Overview
Particle Enhanced Immunoturbidimetric Assay (PENIA)
Cystatin C is produced by all nucleated cells at a constant rate and the production rate in humans appears to be constant over the entire lifetime. Elimination from the circulation is almost entirely via glomerular filtration. The serum concentration of Cystatin C is independent of muscle and gender in the age range of 1 to 50 years. Cystatin C may be of value as a prognostic marker for acute heart failure.
It has been proposed that Cystatin C in serum or plasma is a more sensitive marker for GFR and superior to serum creatinine for estimation of GFR. Calculated eGFR cystatin C is an index of glomerular filtration rate that has particular utility in patients in whom serum creatinine and/or eGFR creatinine may be misleading (e.g. very obese, malnourished adults, older adult).
2-18 years: 0.50 - 1.25 mg/L; 18-60 years: 0.60 - 1.15 mg/L; >60 years: 0.60 - 1.25 mg/L.
2012 CKD-EPI >59 mL/min/1.73m2
Cystatin C – derived eGFR is NOT an appropriate test for patients <18 years old or to evaluate renal function in a patient with acute kidney disease.
Test Details
2 hours.
- CYSC
- Cystatin C
- eGFR
- GFR (Glomerular Filtration Rate)
- Glomerular Filtration Rate (GFR)
Specimen Requirements
Collect specimen in a SST tube. Centrifuge, aliquot serum into a plastic vial and refrigerate. Samples are acceptable for 7 days when stored refrigerated between 2 and 8C.