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Test Code CSTCE Cystatin C with Estimated Glomerular Filtration Rate (eGFR), Serum


Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and serum aliquoted into a plastic vial within 2 hours of collection.


Secondary ID

614154

Useful For

Assessing kidney function in patients suspected of having kidney disease

 

Monitoring treatment response in patients with kidney disease

 

An index of glomerular filtration rate (GFR), especially in patients where serum creatinine may be misleading (eg, very obese, older adults, or malnourished patients)

 

Calculation of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) cystatin C estimated GFR for patients where serum creatinine may be misleading (eg, very obese, older adults, or malnourished patients)

Method Name

Immunoturbidimetric

Reporting Name

Cystatin C with Estimated GFR, S

Specimen Type

Serum

Specimen Minimum Volume

0.25 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  30 days
  Ambient  7 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus Reject

Reference Values

CYSTATIN C:

18-49 years: 0.63-1.03 mg/L

≥50 years: 0.67-1.21 mg/L

0-17 years: Reference values have not been established. Refer to estimated glomerular filtration rate (eGFR).

 

ESTIMATED GFR:

>60 mL/min/BSA (body surface area)

Adult eGFR: Estimated GFR calculated using CKD-EPI Cystatin C equation.(1)

Pediatric eGFR: Estimated GFR calculated using Schwartz Cystatin C equation.(12)

Method Description

Cystatin C:

Serum samples from patients are mixed with latex particles coated with anti-cystatin C antibodies. Human cystatin C agglutinates with latex particles coated with the anti-cystatin C antibodies. The aggregate is determined turbidimetrically at 546 nm.(Package insert: Tina-quant Cystatin C Gen.2. Roche Diagnostics; 01/2017)

 

Estimated GFR is calculated in the laboratory information system, SCC Soft, using the Schwartz Cystatin C equation for patients under 18 years old and the CKD-EPI Cystatin C Equation (2012) for patients 18 years of age and older (Salvador CL, Tondel C, Rowe AD, et al: Estimating glomerular filtration rate in children: evaluation of creatinine- and cystatin C-based equations. Pediatr Nephrol. 2019 Feb;34(2):301-311. doi: 10.1007/s00467-018-4067-3; Inker LA, Schmid CH, Tighiouart H, CKD-EPI Investigators, et al: Estimating glomerular filtration rate from serum creatinine and cystatin C. N Engl J Med. 2012 Jul;367(1):20-29; National Kidney Foundation: CKD-EPI Cystatin C Equation (2012). Accessed March 25, 2021. Available at: www.kidney.org/content/ckd-epi-cystatin-c-equation-2012)

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

82610

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CSTCE Cystatin C with Estimated GFR, S 87430-5

 

Result ID Test Result Name Result LOINC Value
GFRC eGFR by Cystatin C 50210-4
CSTNC Cystatin C, S 33863-2

Forms

If not ordering electronically, complete, print, and send one of the following forms with the specimen:

-General Test Request (T239)

-Cardiovascular Test Request Form (T724)

-Renal Diagnostics Test Request (T830)