Glomerular Filtration Rate, Estimated (eGFR)
Also known as: eGFR, Estimated Glomerular Filtration Rate, GFR, Estimated
Use
The estimated glomerular filtration rate (eGFR) provides an assessment of the filtering capacity of the kidney. Measuring serum creatinine along with an estimated glomerular filtration rate (eGFRcr) is recommended as the first step in GFR evaluation by current clinical practice guidelines.2,3 The eGFR is calculated from a serum creatinine using the CKD-EPI 2021cr equation, which does not include a race coefficient. The National Kidney Foundation and the American Society of Nephrology's Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Diseases recommends calculating estimated glomerular filtration rate (eGFR) without a race coefficient using the CKD-EPI 2021cr equation since it does not include race in the calculation and reporting, includes diversity in its development, and has acceptable performance characteristics and potential consequences that do not disproportionately affect any one group of individuals.4
Special Instructions
Not provided.
Limitations
Estimates of GFR based on serum creatinine may be less accurate for patients at the extremes of muscle mass, those with unusual diets, and those with conditions associated with reduced secretion or extrarenal elimination of creatinine. KDIGO guidelines recommend using additional tests, such as cystatin C, for confirmation when eGFR based on serum creatinine is less accurate.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
Creatinine, serum
AnalyteeGFR
Analyte
LOINC Codes
- 45066-8 - Creatinine + eGFR Pnl SerPlBld
- 2160-0 - Creat SerPl-mCnc
- 98979-8 - eGFRcr SerPlBld CKD-EPI 2021
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.
Collection Instructions
If a red-top tube or plasma is used, transfer the separated serum or plasma to a plastic transport tube.
Storage Instructions
Maintain specimen at room temperature
Causes for Rejection
Hemolysis; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
Other tests from different labs that may be relevant