Use of Cystatin C to Assess Kidney Function
Another setting where cystatin C may have particular advantages over creatinine is in the acute hospitalized patient. Creatinine is produced in muscles, and muscle mass declines quickly with acute illness. Furthermore, blood levels of creatinine often decline acutely in the hospital due to dilutional effects of intravenous fluids. In this prospective study involving intensive-care-unit patients, cystatin C often increased before creatinine, at a threshold of either 50% or 25% over baseline. The average lead time for cystatin C elevation over creatinine was 4 to 6 hours, although larger in many individual patients. Therefore, cystatin C may be useful for detecting acute kidney injury earlier among hospitalized patients. It may also reflect overall GFR better in these acutely ill hospitalized patients, even without acute kidney injury, and help physicians initiate appropriate treatments earlier, and most importantly dose renally excreted drugs more accurately. This is a promising area for use of cystatin C testing that will require further and rigorous evaluation.
Cystatin C in the Acute Hospitalized Setting6
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