CYSTATIN C

Superior GFR marker for the diagnosis and therapeutic control of renal function and Chronic Kidney Disease (CKD)

Gentian Cystatin C Immunoassay – Test Kit

Cystatin C is a superior GFR marker for the diagnosis and therapeutic control of renal function¹ for patients of all ages . The Gentian Cystatin C Immunoassay (ERM-DA471/IFCC standardised) is an open channel turbidimetric test for quantitative determination of cystatin C in human serum and plasma.

The Gentian Cystatin C Immunoassay is FDA510(k) cleared since 2008 and CE-marked. Cystatin C is now certified by TüV SÜD as complying with the European In-Vitro Diagnostic Regulation (IVDR), EU 2017/746

cystatin C blood test for kidney function

Cystatin C in estimating GFR

Cystatin C is an established marker for estimating glomerular filtration rate (GFR). GFR calculations performed using cystatin C are independent of protein intake, ethnicity and muscle mass^2-5. Equations that include cystatin C predict GFR more accurately than serum creatinine in children⁶, adults⁷, and older adults⁸. Clinical use of cystatin C is recommended in guidelines published by KDIGO² and NICE³.

Cystatin C in clinical settings

While the clinical use of cystatin C can have far-reaching benefits across all patient groups, certain vulnerable patient populations may experience a greater benefit. Specifically, children, amputees and the elderly would receive more accurate eGFRs with cystatin C because its concentrations are independent of muscle mass and show less age and gender-related variation relative to creatinine^2-8.

Precise eGFR determination is also important in patients who are prescribed medications that are renally excreted. Drugs with a narrow therapeutic index or toxic range can be more accurately dosed when cystatin C is included in the evaluation of the patients’ kidney function. Cystatin C based dosing of pharmaceuticals such as Digoxin, Carboplatin and Vancomycin can lead to better patient outcomes, decreased length of stay and lower treatment cost⁹.

Insight and resources Cystatin C

Mini-webinar: Can cystatin C eGFR improve accuracy in kidney care?

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Mini-webinar: Disparities in kidney care

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Webinar: AKF webinar about cystatin C

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Webinar: Clinical value of cystatin C in drug dosing

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Webinar: FAQs about cystatin C

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Article: Cystatin C and Shrunken Pore Syndrome

Technical details


Assay Performance
Sample type	Serum, plasma
Assay type	PETIA
Format	Two reagents, ready to use
Measuring range	~ 0.4 - 8.0 mg/L
Precision¹	Total CV < 4 %
Limit of quantification¹	0.43 mg/L
Security zone¹	31.13 mg/L
Standardisation	Calibrated against the reference material ERM-DA471/IFCC
¹Instrument specific, validation results for Roche Cobas c501

The Gentian Cystatin C Immunoassay is FDA510(k) cleared and CE-marked. For more details on Gentian Cystatin C Immunoassay products and prices please contact us at marketing@gentian.com

The Gentian Cystatin C Immunoassay is a Particle-Enhanced Turbidimetric Immunoassay (PETIA) for in vitro diagnostic testing of cystatin C in human plasma and serum samples.

The Gentian Cystatin C Immunoassay is rapidly performed in only 10 minutes and can be applied on a wide range of clinical chemical analysers with documented high inter instrument accuracy.

Compatible with selected clinical chemistry instruments from:

ADVIA^®- Siemens Healthineers
ARCHITECT^®- Abbott Laboratories
- CLIA for Alinity c
AU^®-Beckman Coulter
- CLIA for AU480, AU 5800, AU 680, Immage 800, DxC 700AU
VITROS^®- Ortho Clinical Diagnostics
BS^®- Mindray
Cobas^®- Roche

The Gentian Cystatin C Immunoassay is FDA 510(k) cleared and CE-marked and IVDR certified. For more details on Gentian Cystatin C Immunoassay products and prices please contact us at marketing@gentian.com

The calibrator for the Gentian Cystatin C Immunoassay is available in two versions, one-level calibrator for auto-dilution or a 6-point pre-diluted calibrator kit.

Both types of calibrators are standardised against the international calibrator standard ERM-DA471/IFCC.

The Gentian Cystatin C Immunoassay is FDA510(k) cleared and CE-marked. For more details on Gentian Cystatin C Immunoassay products and prices please contact us at marketing@gentian.com

Product no.	Product	Content
1101	Gentian Cystatin C Reagent Kit	58 mL + 10 mL
1019	Gentian Cystatin C Control Kit	2 x 1 mL
1026	Gentian Cystatin C Control Kit	2 x 5 mL
1029 (USA only)	Gentian Cystatin C Single Use Control Low	100 x 150µL
1030 (USA only)	Gentian Cystatin C Single Use Control High	100 x 150µL
1051*	Gentian Cystatin C Calibrator Kit	6 x 1 mL
1012	Gentian Cystatin C Calibrator	1 mL

*Not for sale in the US

The Gentian Cystatin C Immunoassay is FDA510(k) cleared and CE-marked. For more details on Gentian Cystatin C Immunoassay products and prices please contact us at marketing@gentian.com

Turbidimetric test

Faster throughput

Open channel

10 minutes to result

Cost efficient

Avian antibodies

Contact us for more information and ordering

Gentian's cystatin C immunoassay is applied to turbidimetry-based clinical chemistry platforms. It is an open channel assay, meaning it can be added to all clinical chemistry analysers.

FDA510(k) cleared and CE-marked
IVDR certified
Developed and manufactured by Gentian
Manufactured according to ISO 13485:2016

Explore cystatin C in your laboratory - fill out the form or send an email to marketing@gentian.com for more information about the product and prices.

Frequently asked questions

Why can cystatin C provide an estimate of Glomerular Filtration Rate (GFR)?

Creatinine values are dependent on variables including age and body mass and you must correct for this in calculating GFR. Cystatin C GFR gives a direct and accurate measurement of GFR independent of age and muscle mass.

What is the advantage of using cystatin C for GFR estimation compared to creatinine?

What is the “creatinine-blind area”?

Serum creatinine values are not a direct measure of GFR. GFR can be reduced by as much as 50% while the serum creatinine value is still within the normal range – this is the “creatinine-blind area”.

Does cystatin C GFR have a blind area?

Cystatin C does not have a blind area and gives an immediate and true measurement of GFR.

How does cystatin GFR compare to gold standards for precise determination of GFR?

Gold standard methods include the use of intravenous injections of radio labelled substances such as Cr-51-EDTA and Tc-99m-DTPA, or iodinated agents such as iohexol. GFR determined as cystatin C GFR shows a direct relationship between the reciprocal of cystatin C concentration in serum/plasma and GFR. Correlation is very good and is not hampered by collection errors or errors introduced by multiple measurements of blood or urine samples.

What is the advantage of using cystatin C to estimate GFR compared to gold standard methods for determination of GFR?

The Gentian Cystatin C analysis can be carried out on one routine blood samples, which can conveniently be done together with other standard tests in clinical analysers. Patients do not have to be invaded specifically for the Gentian Cystatin C test. More importantly, Gentian Cystatin C can replace a range of unpleasant tests, including urine collection or radioactive measurements with repeated blood sampling. Especially for paediatricians, Cystatin GFR is the preferred test method.

How can we get access to the Gentian Cystatin C GFR test?

Please contact marketing@gentian.com for information on how to access the Gentian Cystatin C GFR test in your country.

Is the Gentian Cystatin C Immunoassay available on all clinical chemistry analysers?

The Gentian Cystatin C assay is available on most major clinical analyser. Please contact marketing@gentian.com for more information on availability on the clinical analyser in your laboratory.

Is the Gentian Cystatin C Immunoassay standardised?

The Gentian Cystatin C assay is standardised to the international reference material ERM-DA471/IFCC, and has been repeatedly proven to be aligned with the world standards for cystatin C measurement.

Is the Gentian Cystatin C Immunoassay FDA510(k)-cleared?

Yes, the Gentian Cystatin C Immunoassay is FDA510(k) cleared and CE-marked.

Beckman Coulter Customers

For customer service and technical support regarding Gentian products purchased via Beckman Coulter, please contact your local Beckman Coulter representative.If you are looking for package insert in your own language we have package inserts in a selection of languages.

References:

Dharnidharka VR et al. Serum cystatin C is superior to serum creatinine as a marker of kidney function: a meta-analysis. Am J Kidney Dis. 2002.
KDIGO - CKD Evaluation and Management - 2024 Guidelines. 2024
NCIC Clinical guideline (CG182) updated jan 2015 section 2.1 https://www.nice.org.uk/guidance/cg182/chapter/2-Implementation-getting-started.
Tangri N et al. Changes in dietary protein intake has no effect on serum cystatin C levels independent of the glomerular filtration rate. Kidney Int. 2011.
Grubb A. Cystatin C is Indispensable for Evaluation of Kidney Disease. EJIFCC. 2017.
Björk J et al. Validation of standardized creatinine and cystatin C GFR estimating equations in a large multicentre European cohort of children. Pediatr Nephrol. 2019.
Inker LA et al. Estimating glomerular filtration rate from serum creatinine and cystatin C [published correction appears in N Engl J Med. 2012.
Schaeffner ES et al. Two novel equations to estimate kidney function in persons aged 70 years or older. Ann Intern Med. 2012.
Frazee E et al. Cystatin C-Guided Vancomycin Dosing in Critically Ill Patients: A Quality Improvement Project. Am J Kidney Dis. 2017.

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