Coronavirus: Kidney Damage Caused by COVID-19

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COVID-19 — the disease caused by the coronavirus that’s led to the global pandemic —is known to damage the lungs. But, as more people become infected, more understanding of the disease emerges.

Doctors and researchers are finding that this coronavirus — officially called SARS-CoV-2—can also cause severe and lasting harm in other organs, including the heart and kidneys. C. John Sperati, M.D., M.H.S., an expert in kidney health, discusses how the new coronavirus might affect kidney function as the illness develops and afterward as a person recovers.

COVID-19 Kidney Damage: A Possible Complication

Some people suffering with severe cases of COVID-19 are showing signs of kidney damage, even those who had no underlying kidney problems before they were infected with the coronavirus. Early reports say that up to 30% of patients hospitalized with COVID-19 in China and New York developed moderate or severe kidney injury. Reports from doctors in New York are saying the percentage could be higher.

Signs of kidney problems in patients with COVID-19 include high levels of protein in the urine and abnormal blood work.

The kidney damage is, in some cases, severe enough to require dialysis. Some hospitals experiencing surges of patients who are very ill with COVID-19 have reported they are running short on the machines and sterile fluids needed to perform these kidney procedures.

“Many patients with severe COVID-19 are those with co-existing, chronic conditions, including high blood pressure and diabetes. Both of these increase the risk of kidney disease,” Sperati says.

But Sperati and other doctors are also seeing kidney damage in people who did not have kidney problems before they got infected with the virus.

How does COVID-19 damage the kidneys?

The impact of COVID-19 on the kidneys isn’t yet clear. Here are some possibilities doctors and researchers are exploring:

Coronavirus might target kidney cells

The virus itself infects the cells of the kidney. Kidney cells have receptors that enable the new coronavirus to attach to them, invade, and make copies of itself, potentially damaging those tissues. Similar receptors are found on cells of the lungs and heart, where the new coronavirus has been shown to cause injury.

Too little oxygen can cause kidneys to malfunction

Another possibility is that kidney problems in patients with the coronavirus are due to abnormally low levels of oxygen in the blood, a result of the pneumonia commonly seen in severe cases of the disease.

Cytokine storms can destroy kidney tissue

The body’s reaction to the infection may be responsible as well. The immune response to the new coronavirus can be extreme in some people, leading to what is called a cytokine storm.

When that happens, the immune system sends a rush of cytokines into the body. Cytokines are small proteins that help the cells communicate as the immune system fights an infection. But this sudden, large influx of cytokines can cause severe inflammation. In trying to kill the invading virus, this inflammatory reaction can destroy healthy tissue, including that of the kidneys.

COVID-19 causes blood clots that might clog the kidneys

The kidneys are like filters that screen out toxins, extra water and waste products from the body. COVID-19 can cause tiny clots to form in the bloodstream, which can clog the smallest blood vessels in the kidney and impair its function.

Johns Hopkins nephrologists Chirag Parikh and Derek Fine

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Coronavirus Kidney Damage: A Serious Sign

Organ systems like the heart, lungs, liver and kidneys rely on and support one another's’ functions, so when the new coronavirus causes damage in one area, others might be at risk. The kidneys’ essential functions have an impact on the heart, lungs and other systems. That may be why doctors note that kidney damage arising in patients with COVID-19 is a possible warning sign of a serious, even fatal course of the disease.

Can kidneys recover after COVID-19?

As of yet, Sperati says, it’s uncertain how many people with COVID-19-related kidney damage regain their kidney function.

He says, “Patients with acute kidney injury due to COVID-19 who do not require dialysis will have better outcomes than those who need dialysis, and we have seen patients at Johns Hopkins who recover kidney function. We have even had patients in the ICU with acute kidney injury who have required dialysis, and subsequently regained their kidney function. How often that occurs is still not known, but without question, the need for dialysis is a worrisome development in patients with COVID-19.”

Should I keep taking my high blood pressure medication?

Hypertension (high blood pressure) is a common cause of kidney problems. Hypertension damages the blood vessels of the kidneys and affects their ability to filter the blood. Kidneys also help to regulate blood pressure, so kidney damage can make hypertension worse. Over time, hypertension can cause kidney failure.

If you are living with hypertension, you might take medication for the problem. You may be reading news reports questioning the safety of taking certain prescription medicines to manage their condition: ACE inhibitors and angiotensin receptor blockers (ARBs).

Sperati says that patients should stay on their medications and discuss concerns with their doctors.

“Right now there are two sides debating this issue. One side is saying, based on animal studies, that these medications might be harmful, increasing risk of infection. The other says these same drugs might protect against lung damage and other problems associated with COVID-19.

“But all of the professional societies have published articles recommending that you not change your medications,” he says. Staying the course with your prescriptions, he adds, can lower the risk of heart and kidney damage from unchecked high blood pressure.

Sperati does recommend that patients with kidney issues stay away from non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen. These can raise blood pressure and increase fluid volume in the body, which puts strain on the kidneys.

Research is revealing more about SARS-CoV-2 kidney damage

While kidney damage in COVID-19 is still not well understood, more data will reveal how this occurs. Sperati, who also conducts research on kidney disease, says the Johns Hopkins Division of Nephrology is exploring exactly how SARS-CoV-2 — and the body’s response to it — is affecting kidney health.

He says that patients with COVID-19-related kidney damage should follow up with their doctors to ensure kidney function is returning to normal. Lasting kidney damage might require dialysis or other therapies even after recovery from COVID-19.

Mostly, Sperati stresses the importance of adhering to guidelines around physical and social distancing and hand-washing, the basics of prevention. “For everyone, especially people with underlying chronic disease, avoiding infection with COVID-19 for as long as you can is crucial,” he says.

“Right now, we don’t have a treatment or vaccine for this disease. The longer a person can go without getting infected, the better chance they have of benefiting from a future therapy.”

Scientist carefully insets a pipette into a test tube.

Coronavirus (COVID-19)

What you need to know from Johns Hopkins Medicine.

Updated: May 14, 2020