Cystatin C

0-1 years old: 0.59-1.97 mg/L

>1 year old: 0.64-1.23 mg/L

• An estimated Glomerular Filtration Rate (eGFR) by Cystatin C calculation (eGFR CysC) will be calculated and reported along with the Cystatin C result using the eGFR_cys (CKD-EPI 2012) calculation for patients 18 years and older. In accordance with NFK recommendations, calculated eGFR CysC values ≤90 are reported as a whole numbers and values calculated above this cutoff for adults will be reported as >90 mL/min/1.73 m².
• An eGFR CysC <18Y for patients <18 years of age will be calculated when a cystatin C value is resulted using the CKiD U25 calculation in accordance with the National Kidney Foundation and American Society of Nephrology Task Force recommendations.
  • For patients <18 yrs, if both a cystatin C value eGFR and creatinine eGFR are reported, and average (mean) of each will be reported as the eGFR Average <18y.
• ^{The eGFR CysC or eGFR CysC <18Y values should be interpreted based on clinical context.}