3018316
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Cystatin and Creatinine With eGFR

GFR CYS
Example Reports
Abnormal
Normal
Pediatric

Ordering Recommendation

Use to calculate glomerular filtration rate when serum creatinine may be misleading, e.g., in individuals who are elderly, have severe obesity, or are malnourished.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube, plasma separator tube, K2EDTA, K3EDTA, or lithium heparin

Specimen Preparation

Allow serum tube to clot completely at room temperature. Separate serum or plasma from cells within 2 hours of collection. Transfer 1 mL plasma or serum or plasma to an ARUP standard transport tube. (Min: 0.2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Blood collected in capillary blood collection tubes is unsuitable for use in this assay.

Remarks

Patient age and sex are required for calculation.

Stability

After separation from cells: Ambient: 7 days; Refrigerated: 7 days; Frozen: 3 months

Methodology

Quantitative Enzymatic Assay

Performed

Sun-Sat

Reported

Within 24 hours

Reference Interval

Refer to Report

Calculated GFR - >= 60 mL/min / 1.73 square meters

Interpretive Data

The estimated glomerular filtration rate (eGFR) was calculated using the 2021 CKD-EPI eGFR creatinine-cystatin equation. This equation is validated in individuals 18 years of age and older. Accurate estimation of GFR requires stable day-to-day filtration markers (creatinine and cystatin C). Filtration markers are influenced by non-GFR determinants, including generation from cells and diet, tubular secretion and reabsorption, and extra-renal elimination. These determinants may affect eGFR accuracy. The eGFR is normalized to a body surface area of 1.73 square meters.


GFR Categories in Chronic Kidney Disease (CKD)
GFR Category GFR (mL/min/1.73 square meters) Interpretation
G1 90 or greater Normal to high*
G2 60-89 Mild decrease*
G3a 45-59 Mild to moderate decrease
G3b 30-44 Moderate to severe decrease
G4 15-29 Severe decrease
G5 14 or less Kidney failure
*In the absence of evidence of kidney damage, neither GFR category G1 nor G2 fulfill the criteria for CKD (Kidney Int Suppl 2013;3:1-150)

Compliance Category

FDA

Note

Hotline History

View Hotline History

 

Hotline History

Date of Change
Test Name Change
Methodology
Performance/Reported Schedule
Specimen Requirements
Reference Interval
Interpretive Data
Note
CPT Code
Component Change
Other Interface Change
New Test
Inactive
10/21/2024
X
N/A

CPT Codes

82610; 82565

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Components

Component Test Code* Component Chart Name LOINC
0020025 Creatinine, Serum or Plasma 2160-0
3018317 Cystatin C 33863-2
3018318 eGFR by CKD-EPI Creatinine-Cystatin 2021 98980-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.

Aliases

Cystatin and Creatinine With eGFR