Use of Cystatin C to Assess Kidney Function
This slide clearly demonstrates both the utility and problems with using serum creatinine alone to estimate GFR. Serum creatinine numbers are plotted against measured GFR in a large number of individuals with and without kidney disease. In general, it is quite true that serum creatinine increases as GFR falls. However, creatinine does not increase very much until GFR is well below 60 mL per minute per 1.73 m2. Such a person already would have stage 3 chronic kidney disease. The dotted line corresponds to a serum creatinine of 1.2 milligrams per deciliter, the upper limit of the reference range. Such a serum creatinine could correspond to a GFR as low as 25 or as high as 130 mL per minute per 1.73 m2.
Creatinine as a Marker of GFR: It Works But...
Jump to section:
- A Case
- What do the kidneys do?
- Why Measure Renal Function?
- How Is Chronic Kidney Disease (CKD) Defined?
- Stages of Chronic Kidney Disease
- Laboratory Assessment of Kidney Function: What Can We Measure?
- Creatinine as a Marker of GFR
- Creatinine as a Marker of GFR: It Works But...
- How Can We Turn the Serum Creatinine Into a Better Estimate of GFR?
- Revised eGFR Equation (ID-MS version)
- eGFR Equation Works, But it's Not Perfect
- What About Cystatin C?
- Mayo Renal Laboratory Cystatin C By Particle Enhanced Turbidometric Immunoassay (PETIA)
- Comparison To Current Nephelometric Assay (PENIA) Reveals 23% Bias
- Cystatin C PENIA Assay Shift (19%)
- Cystatin C eGFR Using Published Equation* Performs Well3
- Cystatin C Equations Categorize Patients Slightly Better Than MDRD eGFR
- Cystatin C Reference Range
- PETIA Cystatin C Reference Range
- Cystatin C: Useful To Confirm Those At Risk Of CKD Progression And Its Complications (REGARDS)4
- Cystatin C: CKD Progression and Complications (MESA and CHS)5
- Cystatin C in the Acute Hospitalized Setting6
- Back to Our Patient
- Potential Interventions