This video is part of “Innovations in: Kidney disease,” an editorially independent special report that was produced with financial support from Vertex.
Imagine it’s the first day of summer and you have a pool full of water so clear you can see right through it. You have big plans to splash around and cool off in it all summer.
But then the filter breaks. Everything that goes into the pool seems to stay there. Leaves, trash and mysterious dirt build up, and the pool quickly becomes unusable.
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Now imagine that the pool is your body, and the filters that failed are your kidneys. How long do you think you would last if the filters failed?
During a day, our kidneys take in around 150 liters of blood. If you had to drink that much liquid, you’d have to chug a liter and a half every hour, 24 hours a day, for the rest of your life.
Your kidneys do this automatically by passing your blood through millions of filtering units called nephrons, which have two main parts: the glomerulus and the tubule.
The glomerulus consists of small blood vessels whose thin walls filter waste and water through – while retaining blood cells and larger molecules.
The waste and water then enter the tubule, where it flows alongside a blood vessel that holds the filtered blood from the glomerulus. This allows the tubule to return the nutrients and water we need back to our blood, which will then return to our body. What is not returned to our blood is converted into our urine.
Your kidneys do the impossible for you every day of your life – keeping you alive by constantly filtering your blood so you can maintain the right balance of nutrients, salts and water that all our cells need to function properly. But in people with chronic kidney disease, the kidneys begin to lose function, disrupting the balance their body depends on and leading to complications such as anemia, nerve damage, and bone damage.
Around 10 percent of adults worldwide are affected by kidney disease, but the condition is difficult to diagnose. And the lack of a cure means that more than a million people will die each year from the condition. So what is kidney disease and why is it so challenging to treat?
The exact cause of a case of kidney disease is not always known, but it is often due to diabetes or high blood pressure.
With diabetes, high blood sugar levels can damage the filters in the kidneys, making it harder for the organs to perform their function and make them pass important proteins through the urine.
High blood pressure can cause blood to pass through the kidneys with such force that it damages their tissue. This damage can create a vicious cycle: declining kidney function allows more waste to remain in the blood, more waste increases blood pressure, and higher blood pressure causes more kidney damage.
Doctors can diagnose kidney disease using tests that assess the amount of waste or protein present in a patient’s blood or urine.
Diagnosed kidney disease has five stages. These range from stage 1, where the kidneys are still able to function normally, to stage 5, where the kidneys are close to failure or have failed.
Doctors determine the stage of a patient’s kidney disease by taking a blood test to measure eGFR, their estimated glomerular filtration rate. This reflects how much blood a person’s kidney is able to filter each minute. If less blood is filtered, more kidney function has been lost, indicating that the disease is further along.
Although there are diagnostic tests, one of the biggest challenges with kidney disease is that many people do not show symptoms until the disease is quite advanced. And there is no cure for chronic kidney disease.
As a result, treatments for kidney disease often revolve around managing the causes and complications of the disease, as well as slowing the decline of the kidneys.
For example, if a person’s kidney disease is linked to diabetes or high blood pressure, treatment will involve managing those conditions as well.
Even if a person’s high blood pressure is not the direct cause of the kidney disease, they may be prescribed medication to control their blood pressure to prevent the disease from worsening.
In addition, lifestyle changes such as reducing salt intake and increasing exercise can help manage kidney disease and the many complications it can cause.
When only 10 to 15 percent of a person’s kidney function remains, they have few options left. They must either rely on a treatment such as hemodialysis, which uses a machine to filter the blood, or receive a kidney transplant, either from a living or deceased donor.
Both dialysis and transplants are effective. It is also not a cure for kidney disease. And people who have had a kidney transplant must take immunosuppressants to make sure their bodies don’t attack the new organ.
But researchers are working on new treatments. Some have identified key genes involved in the disease that may provide targets for future therapies.
And a clinical trial is currently underway to test the use of a person’s own kidney cells to treat their disease.
Researchers take some tissue from the participants’ kidneys, grow larger batches of a subset of cells from that tissue, and then inject those cells back into the participants. The research team hopes that the cells will be able to repair the organs.
Kidney disease is a complex disease. Although we have the tools to diagnose it, it is difficult to catch the disease in time. And finding a cure will require the coordinated work of researchers, doctors and patients alike.
What we don’t have to wait for is respect for our kidneys—the humble, bean-shaped filters that keep our bodies as clean and refreshed every day as a well-managed pool in summer.
