FAQ: Advantages of measuring cystatin C in addition to creatinine?
28. Apr 2020 |
4 min read
In this segment we will answer questions our Product Manager for cystatin C and Product Specialist in the US get about cystatin C at exhibitions, conferences and client meetings. Today’s question is “What are the advantages of measuring cystatin C in addition to creatinine?”
What are the advantages of measuring Cystatin C in addition to Creatinine?
One advantage of measuring cystatin C in addition to creatinine stems from the fact that cystatin C is less susceptible to factors that affect muscle mass (age, diet, sex, physical activity, etc.).
Cystatin C is constitutively expressed in all nucleated cells resulting in similar serum concentrations among individuals with the same kidney function . By contrast, creatinine is released by skeletal muscles as a by-product of muscle metabolism. Consequently, individuals with varying muscle mass but the same kidney function have different serum concentrations of creatinine and therefore different creatinine-based eGFRs.
Another benefit of using cystatin C as a supplemental marker of renal function is that it allows for diagnosis of chronic kidney disease (CKD) in its early stages. Whereas serum creatinine concentrations are unresponsive to changes in GFR between 40 – 70 ml/min/1.73 m2 (“creatinine blind area”), cystatin C concentrations in blood correlate well with GFR changes within this range. In fact, individuals diagnosed with CKD by creatinine without confirmatory cystatin C testing have been found to be at similar risk of heart failure, end stage renal disease (ESRD) and death when compared with individuals with no CKD . Incorporating cystatin C into clinical practices could therefore improve prognostic risk stratification and improve clinical outcomes for CKD patients who make up more than 10% of the global population.
Gentian Cystatin C
Gentian’s cystatin C immunoassay was launched in 2006. It is a Particle-Enhanced Turbidimetric Immunoassay (PETIA) for in vitro testing of cystatin C in human plasma and serum samples. The test has documented high inter-instrument accuracy on a wide range of clinical chemistry analysers and can be performed in as little as 10 minutes.