Module CC-17 · Version 1.0
Creatinine, Cystatin C, and Estimated GFR
Creatinine and cystatin C are filtration markers, not direct measurements of glomerular filtration rate. Each marker is generated and handled by the kidney differently, the current race-free CKD-EPI equations require specific inputs, and a single eGFR is likely to mislead during acute kidney change, extremes of muscle mass, diet, pregnancy, in children, and during transplant evaluation. A paired creatinine-only and creatinine-cystatin C calculation walks through to a bench decision.
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Who this module is for
Clinical laboratory scientists and laboratory trainees who release chemistry results and need to interpret or explain an eGFR
Learning objectives
- Explain how creatinine and cystatin C relate to filtration and to non-GFR determinants
- Identify the equation, units, age limits, and population assumptions associated with an eGFR
- Recognize when combined creatinine-cystatin C estimation or measured clearance may better answer the question
How completion works
Mark every required section done and answer every knowledge check in those sections correctly. The final save completes the module automatically.
Sources
15 sources
1. KDIGO. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117-S314.
Source note · professional society guidance
2. KDIGO. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl. 2012;2(1):1-138.
Source note · professional society guidance
3. KDIGO. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation. 2017;101(8S):S1-S109.
Source note · professional society guidance
4. National Kidney Foundation. CKD-EPI Creatinine Equation (2021).
Source note · professional society guidance
5. National Kidney Foundation. CKD-EPI Creatinine-Cystatin C Equation (2021).
Source note · professional society guidance
6. National Kidney Foundation. Recommendations for Implementing the CKD-EPI 2021 Race-Free eGFR Calculation: Guidelines for Clinical Laboratories.
Source note · professional society guidance
7. NIDDK. eGFR Calculators for Adults and Pediatrics.
Source note · federal guidance
8. Inker LA, Eneanya ND, Coresh J, et al. New Creatinine- and Cystatin C-Based Equations to Estimate GFR without Race. N Engl J Med. 2021;385(19):1737-1749.
Source note · peer-reviewed literature
9. Myers GL, Miller WG, Coresh J, et al. Recommendations for Improving Serum Creatinine Measurement: A Report from the Laboratory Working Group of the National Kidney Disease Education Program. Clin Chem. 2006;52(1):5-18.
Source note · peer-reviewed literature
10. Wu CK, et al. Cystatin C is a disease-associated protein subject to multiple regulation. Immunol Cell Biol. 2015. PMCID: PMC7165929.
Source note · peer-reviewed literature
11. Association Between Serum Cystatin C and Thyroid Diseases: A Systematic Review and Meta-Analysis. PMCID: PMC8639734.
Source note · peer-reviewed literature
12. Roche Diagnostics. Tina-quant Cystatin C Gen.2 (CYSC2) Method Sheet, cobas c 701/702, V6.0, October 2023.
Source note · manufacturer labeling
13. 42 CFR 493.1253 - Standard: Establishment and verification of performance specifications (with related 493.1255, calibration and calibration verification). Electronic Code of Federal Regulations.
Source note · federal regulation
14. Nair S, et al. Effect of a Cooked Meat Meal on Serum Creatinine and Estimated Glomerular Filtration Rate in Diabetes-Related Kidney Disease. Diabetes Care. 2014;37(2):483-487.
Source note · peer-reviewed literature
15. College of American Pathologists. Chemistry and Toxicology Checklist, CHM.15225 eGFR and LDL Cholesterol Calculated Test Results (Phase I). CAP Accreditation Program, 12.09.2025 edition.
Source note · accreditation standard