eGFR Creatinine-Cystatin C Calculation With Albumin:Creatinine-Protein:Creatinine Ratios, Urine
Use
An estimated 37 million U.S. adults have chronic kidney disease (CKD). In addition to cardiovascular-associated events, they are at risk for kidney failure or end-stage kidney disease(ESKD) requiring dialysis or kidney transplant. In the 2015-2016 National Health and Nutrition Examination Survey, prevalence of CKD stages G1-4 was 14.2% among adult participants. One in three U.S. adults is at risk for CKD due to prevalent risk factors such as diabetes and/or high blood pressure. The incidence of CKD is projected to increase during the next 20 years because of increasing obesity rates and an aging U.S. population.1
Special Instructions
Asymptomatic individuals with risk factors such as diabetes, hypertension, family history of kidney disease, and cardiovascular disease are recommended to undergo this testing routinely, at least annually. It is important to consider multiple urine protein measurements to detect other CKD etiologies.
Limitations
Cystatin C values are not influenced by muscle mass and nutrition but are instead affected by factors different from those impacting creatinine values. Creatinine levels may not increase until GFR reduces by roughly 50%, highlighting the necessity for multiple markers for precise evaluation.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
Result Turnaround Time
2-5 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.5 mL
Minimum Volume
1 mL
Container
Gel-barrier tube
Collection Instructions
If green-top (heparin) tube is used, separate plasma from red blood cells and transfer plasma to a transfer tube.
Storage Instructions
Room temperature
Causes for Rejection
Specimen other than serum or heparinized plasma; grossly hemolyzed (>1,000 mg/dL Hgb) samples; excessive turbidity and clots in samples or bloody urine
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days at 15°C to 25°C |
| Refrigerated | 7 days at 2°C to 8°C |
| Frozen | 14 days at -25°C |