Lexicon
Cystatin C
Definition
How it works
Glomerular filtration rate can be estimated from serum concentrations of endogenous filtration markers, and cystatin C-based equations are used as a confirmatory test for a more accurate GFR assessment than creatinine alone. [3] Serum creatinine is influenced by muscle-related and other non-renal factors, whereas serum cystatin C and its combination with creatinine may serve as an alternative because these factors do not affect it. [4]
Connected concepts
How it's measured
The 2012 KDIGO guidelines recommended using cystatin C to confirm the diagnosis of chronic kidney disease determined by creatinine-based eGFR and to estimate kidney function when accurate estimates are needed for clinical decision-making. [1] Transition of all reagents and estimated-GFR equations to the newly established International Standard is critical for developing generalizable cystatin C data. [2] Serum creatinine and serum cystatin C are the most widely used renal biomarkers for calculating the estimated glomerular filtration rate, which is used to estimate the severity of kidney damage. [5]
What levels mean
Lower eGFR based on creatinine combined with cystatin C is significantly associated with higher risk of adverse kidney outcomes, cardiovascular outcomes, and other health outcomes, including in the mildest categories of chronic kidney disease. [6] Among outpatients, a cystatin C-based eGFR at least 30% lower than the creatinine-based eGFR was associated with higher all-cause mortality (HR 1.69, 95% CI 1.57-1.82) and cardiovascular mortality (HR 1.61, 95% CI 1.48-1.76). [7] The creatinine to cystatin C (Cr/CysC) ratio is the most frequently used diagnostic biomarker for
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Highlighted the creatinine-to-cystatin C ratio as a practical, low-cost readout for emerging sarcopenia: when that ratio runs high, muscle…
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- 1.Chen DC, Potok OA, Rifkin D, Estrella MM. Advantages, Limitations, and Clinical Considerations in Using Cystatin C to Estimate GFR. Kidney360 · 2022
- 2.Benoit SW, Ciccia EA, Devarajan P. Cystatin C as a biomarker of chronic kidney disease: latest developments. Expert Rev Mol Diagn · 2020
- 3.Inker LA, Titan S. Measurement and Estimation of GFR for Use in Clinical Practice: Core Curriculum 2021. Am J Kidney Dis · 2021
- 4.Ávila M, Mora Sánchez MG, Bernal Amador AS, Paniagua R. The Metabolism of Creatinine and Its Usefulness to Evaluate Kidney Function and Body Composition in Clinical Practice. Biomolecules · 2025
- 5.Pottel H, Delanaye P, Cavalier E. Exploring Renal Function Assessment: Creatinine, Cystatin C, and Estimated Glomerular Filtration Rate Focused on the European Kidney Function Consortium Equation. Ann Lab Med · 2024
- 6.
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