Glomerular Filtration Rate, Estimated (eGFR)

Casandra

Casandra Test Code LC62509Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 100768CPT Code 82565

Glomerular Filtration Rate, Estimated (eGFR)

Also known as: eGFR, Estimated Glomerular Filtration Rate, GFR, Estimated

Clinical Use

Order Test

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

The CKD-EPI 2021cr equation does not include a race coefficient. Normal GFR in young adults is approximately 120−130 mL/minute/1.73 m2. A value of less than 60 mL/minute/1.73 m2 for three months or more is indicative of CKD.

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.

Test Details