Chronic kidney disease affects about 10 percent of the population and is often only detected at a relatively late stage. 'The early stages of kidney disease are without symptoms,' said De Borst. 'In addition, the kidneys have reserve capacity, so kidney function may still be normal despite extensive damage. As a result, kidney disease is often diagnosed at an advanced stage, regularly even when kidney failure is already present.'
Blood levels of the muscle waste product creatinine are now used to determine whether kidney damage is present. A higher creatinine level in the blood means the kidneys are working worse. De Borst: 'However, the amount of creatinine also depends on muscle mass and therefore differs per person. A bodybuilder has higher blood creatinine levels than someone who is very slim. I am therefore looking for a marker exclusively related to the extent of kidney damage.'
In this search, De Borst uses artificial intelligence (AI). 'From a large amount of data, I want to investigate as many substances as possible that can be found in blood and urine. By applying AI, I want to pinpoint a new single marker or a combination of them, that better reflects the degree of kidney damage than creatinine.'
De Borst will use samples that are already available: 'We have been collecting blood and urine samples from lots of people in our Transplantlines biobank for years. Those materials are waiting to be used for research. I want to analyse the data of about 1,000 people.' By collaborating with his colleagues at the Mayo Clinic (USA) and the Karolinska Institute (Sweden), among others, De Borst wants to expand this number to more than 3 000.
According to de Borst, this analysis can lead to earlier identification of kidney damage. 'In healthy kidneys, about a million filters, called nephrons, are active. I am looking for a marker that can check how many of these nephrons are still working. I hope that through such a marker we can identify kidney damage earlier at an earlier stage than we can now. But we can also develop new markers for early kidney damage by looking very closely at the kidney in biopsies, small pieces of tissue taken from our patients.'
The importance of this research for patients is huge. De Borst: 'Kidney failure is the end-stage of kidney disease, requiring a transplant or dialysis for patients to stay alive. If we can identify kidney damage earlier, that likely prevents a lot of suffering for patients.'
According to De Borst, the new marker can probably be used in combination with already existing methods, such as creatinine but also the amount of albumin in the urine (albuminuria). 'We aim to establish whether timely identification and treatment will reduce the risk of kidney failure and cardiovascular disease, a common complication of kidney disease. This new study can help in reaching those goals.'
Professor of nephrology Martin de Borst has received an ERC Consolidator Grant worth two million euros from the European Research Council (ERC) for this research. These Grants are awarded to excellent researchers with at least seven and up to twelve years of research experience. They must demonstrate the pioneering nature, ambition and feasibility of their scientific proposal. The funding has been provided for five years; this will allow De Borst to appoint several PhD students and postdoc researchers.
