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Test Code LABCYCR Cystatin C and Creatinine with estimated GFR

Clinical Information

This test includes serum/plasma measurements of cystatin C and creatinine and reports an estimated GFR based on the 2021 CKD-EPI equation refit without a race variable.

Synonym

  • CYSC

Profile Information

Reporting Name Available Separately Always Reported
Cystatin C No Yes
Creatinine Yes Yes
eGFR No Yes

Specimen Required

Preferred Container/Tube: Mint Green Top
Acceptable Container/Tube: Mint Green Top, Gold SST Top
Specimen Volume: 3 mL
Specimen Minimum Volume: 1 mL

Specimen Stability Information

Ambient: 5 days
Refrigerated: 5 days

Rejection Due To

  • Gross hemolysis
  • Gross icterus
  • Quantity not sufficient
  • Quality not acceptable

Reference Values

FEMALE MALE

Cystatin C
0.51-1.05 mg/L

 

Creatinine
0-30 days: 0.50-0.90 mg/dL
31-365 days: 0.40-0.60 mg/dL
1-3 years: 0.40-0.70 mg/dL
4-6 years: 0.50-0.80 mg/dL
7-9 years: 0.50-0.90 mg/dL
10-12 years: 0.60-1.00 mg/dL
13-15 years: 0.70-1.10 mg/dL
16-18 years: 0.80-1.20 mg/dL
19+ years: 0.50-1.20 mg/dL

 

eGFR
≥60 mL/min/1.73m2

Cystatin C
0.51-1.05 mg/L

 

Creatinine
0-30 days: 0.50-1.20 mg/dL
31-365 days: 0.40-0.70 mg/dL
1-3 years: 0.40-0.70 mg/dL
4-6 years: 0.50-0.80 mg/dL
7-9 years: 0.60-0.90 mg/dL
10-12 years: 0.60-1.00 mg/dL
13-15 years: 0.60-1.20 mg/dL
16-18 years: 0.80-1.40 mg/dL
19+ years: 0.70-1.30 mg/dL

 

eGFR
≥60 mL/min/1.73m2

 

Cautions

Creatinine results may be falsely decreased in icteric samples. In some cases of monoclonal gammopathies (especially Waldenstrom's macroglobulinemia with very high concentrations of IgM), creatinine results may be unreliable.

Method Description

CYSTATIN C

Turbidometric

 

CREATININE

Kinetic Jaffe

 

CKD-EPI 2021 Calculation. eGFRcr-cys = 135 x min(Scr/κ, 1)α x max(Scr/κ, 1)-0.544 x min(Scys/0.8, 1)-0.323 x max(Scys/0.8, 1)-0.778 x 0.9961Age x 0.963 [if female]

 

where   κ = 0.7 (females) or 0.9 (males)
a = -0.219 (female) or -0.144 (male)
Scr = serum creatinine in mg/dL
Scys = serum cystatin C in mg/L
Age (years) 

 

The “min (Scr/κ, 1)” factor indicates the minimum of Scr/κ or 1.0, “max(Scr/κ, 1)” indicates the maximum of Scr/κ or 1.0, “min(Scys/0.8, 1)” indicates the minimum of Scys/0.8 or 1.0, and “max(Scys/0.8, 1)” indicates the maximum of Scys/0.8 or 1.0.

Performing Lab

Clinical Lab UH

Day(s) Performed

Monday through Sunday

Report Available

Same day/1 day

Reporting Name

Cystatin C and Creatinine with estimated GFR

CPT Code Information

82565
82610

LOINC Code Information

2160-0
98980-6