Use of Cystatin C to Assess Kidney Function
Serum creatinine is a tried and true marker of GFR. Creatinine is a byproduct of muscle turnover. In general, production of creatinine is very constant from day-to-day in any given individual. Exceptions would include situations where muscle is rapidly damaged such as rhabdomyolysis, or individuals that greatly increase or decrease muscle mass over time. Creatinine is a very small molecule that is freely filtered in the kidney. Hence, clearance of creatinine is proportionate to GFR. However, it is well established that a small amount of creatinine is also secreted by kidney tubules. Therefore, creatinine clearance will always overestimate GFR to some extent. Furthermore muscle mass varies greatly between individuals depending on their age, gender, and size.
Creatinine as a Marker of GFR
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- 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