Cystatin C test: Developing a rapid test to allow users to track kidney function

Working with Bloom Diagnostics, Global Access Diagnostics (GADx) developed a Kidney Test to measure cystatin C level, a well-established indicator of kidney function.

What is CKD?

Kidneys play a vital role in filtering blood; removing toxins, excess salt and waste products while maintaining a healthy balance of water, salts and minerals. Chronic kidney disease (CKD) is a gradual loss of kidney function which can eventually lead to kidney failure. 

An estimated 11% of the human population suffer from chronic kidney disease, with risk factors including diabetes (Type 1 and 2); high blood pressure; family history; older age, obesity, smoking and long term use of non-steroidal anti-inflammatory drugs.

Why Cystatin C?

Glomerular filtration rate (GFR) is the standard measure of kidney function, and can be accurately measured by inulin clearance, however this procedure is lengthy and complex. Cystatin C is a well-established alternative indicator for estimating GFR, widely used in clinical practice by healthcare professionals. Cystatin C is a small protein produced by cells that can easily be measured in blood. It is removed from the bloodstream by glomerular filtration in the kidneys, so if kidney function declines, the blood levels of Cystatin C will rise.

Developing a Cystatin C test

Bloom Diagnostics came to GADx with a clear and precise set of requirements for a Cystatin C test, for incorporation into their existing Bloom Lab platform. GADx was able to use its strong background in the development and optimisation of rapid diagnostic tests to produce a test that met all the required specifications. While Bloom Diagnostics maintained legal manufacturer status, a highly collaborative approach was taken in which GADx provided support in analytical verification testing and the preparation of documentation for the design history file. Finally, GADx has worked with Bloom to bring the test to market, supporting with device card manufacturing and QC.  

The result: Expansion of Bloom’s product portfolio to include a Kidney Test

Within a few minutes and using just a drop of blood, users can gain valuable insight into their kidney function and obtain personalized recommendations. Further details can be found here: Bloom Diagnostics

About the partners

Bloom Diagnostics was founded in 2018 by Dr. Angelica Kohlmann and Thomas Kupper and is ISO 13485 and ISO 9001 certified. The company’s product portfolio includes the Covid Antibody Test, Ferritin Test, Ovarian Reserve Test, Thyroid Test and Kidney Test. Bloom’s sophisticated system allows consumers to take control of their own health. Its innovative hardware and software can identify a range of medical conditions using a combination of advanced biotechnology, cloud computing and scientific research.

References

Zahran A, El-Husseini A, Shoker A (2007). “Can cystatin C replace creatinine to estimate glomerular filtration rate? A literature review”. American Journal of Nephrology. 27 (2): 197-205. doi:10.1159/000100907PMID17361076S2CID25523216.

Frequent testing is invaluable and so it is vital to find ways to drive down the cost of kits and increase production levels. As a social enterprise, GADx can transform this process because it ‘breaks the link’ of ‘having to make profit for shareholders’.

Paul Davis
Co-founder of Mologic and pioneer of lateral flow diagnostics.