Test Updated: 07/13/2022
Test Overview
Test Methodology

Particle Enhanced Immunoturbidimetric Assay (PENIA)

Test Usage

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).

Reference Range *

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.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Analytic Time

2 hours.

Soft Order Code
MiChart Code
Cystatin C, Serum
  • CYSC
  • Cystatin C
  • eGFR
  • GFR (Glomerular Filtration Rate)
  • Glomerular Filtration Rate (GFR)
Chemical Pathology
Specimen Requirements
Collection Instructions

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.

Alternate Specimen
Red top, Green top tube (lithium heparin )or Lavender (EDTA).
Normal Volume
0.5 mL serum
Minimum Volume
0.25 mL serum
CPT Code
Fee Code