The human kidneys filter about 1,500 litres of blood daily and control the water and mineral balance of the body to a large extent. Without them, our body would very quickly poison itself. Even limited kidney performance can lead to complaints such as swelling of the legs or face, fatigue, nausea, weight loss or muscle cramps.
Approximately 850 million people worldwide have kidney disease. According to the German Kidney Foundation, four to six million people in Germany are affected by impaired kidney function. Approximately eight million suffer from chronic kidney disease, 80,000 patients are treated with dialysis in the long term, and about 8,000 of them are waiting for a kidney transplant. According to figures from the Robert Koch Institute, persons under 50 years of age are rarely affected, whereas in the age group between 70 to 79, every eighth person is affected, with women suffering from kidney disease more frequently than men.
Diabetes mellitus and high blood pressure are the most important risk factors for chronic kidney disease. If the dysfunction is so advanced that the kidneys fail completely, patients can be treated with dialysis (blood washing); in the long term, often only a kidney transplant will help.
Cause-and-Effect Research Using Huge Mountains of Data
Scientists from more than 270 research departments worldwide have evaluated data from 1.05 million study participants under the leadership of the University Hospital Freiburg in order to identify new risk genes for kidney diseases. In this multi-year project, they were able to identify 166 gene sites for the first time. According to the scientists, eleven of these genes harbor particularly relevant risk variants that might be important for drug development.
“Our study helps to understand how kidney damage occurs and provides urgently needed approaches for new therapies”, said first author Dr. Matthias Wuttke, physician and scientist at the Institute of Genetic Epidemiology at the University Hospital Freiburg. “Chronic kidney disease is one of the most rapidly increasing cause of death in the last ten years. However, they are hardly noticed by the public.”
In order to prove that the occurrence of certain gene variants is related to kidney disease, the researchers evaluated data sets from the international “Chronic Kidney Disease Genetics (CKDGen) Consortium” and the U.S. “Million Veteran Program”. “Only the enormous size of our study enabled us to find so many new gene sites that are very likely to favour kidney diseases”, said Prof. Dr. Anna Köttgen, Director of the Institute of Genetic Epidemiology at the University Hospital of Freiburg.
Hope for the New Treatment Methods
So far, 166 of the total of 264 gene mutations found had no known effect on kidney function. “Eleven of the identified genes seem particularly promising for a therapeutic approach. We hope that on this basis of this, new ways can be found to treat kidney diseases”, said co-author Dr. Yong Li from the Institute of Genetic Epidemiology.
In their study, the researchers focused in particular on genes that influence the ability of the kidneys to free the blood of harmful substances by filtration. In addition, they compared the gene activity of 46 tissue types of the entire body. It was found that many relevant gene alterations lead to a change in gene activity in the tissue of the kidneys and the urogenital tract. “This strongly suggests that new therapies should also start directly in these tissues”, says Wuttke.
The study was published on 31 May 2019 in the journal Nature Genetics.