NIH report details how severe forms of COVID-19 cause lung failure and death

A recent report from the National Institutes of Health published on May 11 details how severe COVID-19 is unlike most respiratory illnesses and why it can cause lung failure and death. 

The report cites two NIH-funded studies that were both published in the scientific journal Nature. The NIH says these studies provide some of the most detailed analyses of COVID-19 on the human body. 

Researchers explained how SARS-CoV-2, the disease that causes COVID-19 "unleashes a devastating series of host events in the lungs prior to death." 

These "events" include irreparable tissue damage and severe inflammation. 

In both studies, scientists analyzed tissue samples gathered from COVID-19 patients shortly after their deaths. After implementing a rapid autopsy program on the tissue samples, researchers found that the lungs of the people who died of severe COVID-19 were filled with immune cells known as macrophages. 

Macrophages are a type of white blood cell that typically help fight off viruses, however, in the case of these deceased COVID-19 patients, the macrophages produced severe inflammation that further damaged the lung tissue. 

COVID-19 has been known to cause the body’s immune system to have an overreaction to the virus, causing severe inflammatory responses which can cause organ and tissue damage. 

Researchers also noted that in cases of a typical respiratory infection, like the seasonal flu, the lung usually repairs the damage. Both NIH studies found that this isn’t always the case with severe forms of COVID-19. 

Both studies noted that lung tissue from patients with severe forms of the novel coronavirus contained unusually large numbers of fibroblast cells, a type of cell that is responsible for tissue repair but when overworked can cause damage. 

Researchers say the high numbers of fibroblast cells indicate rapid lung scarring. 

Researchers not only identified devastating impacts from COVID-19 on the lungs but damage to other parts of the body including the liver, kidney, and heart tissue of patients who have died from the virus. 

"A closer look heart tissue revealed widespread damage, documenting that many different coronary cell types had altered their genetic programs," the NIH wrote in the report. 

Since the onset of the pandemic, the novel coronavirus has exhibited an array of ever-evolving symptoms and long-term effects. 

Several studies have shown that while COVID-19 was originally thought to be like any other respiratory illness impacting the lungs, researchers have begun to realize that this deadly virus also harms other parts of the body including the heart and brain. 

One study published on June 25 in the journal Cell Reports Medicine, found that while COVID-19 is commonly known as a respiratory illness, the disease has also been known to instigate inflammatory responses in the body which can negatively affect the function of one’s heart and brain.

According to the study, researchers observed SARS-CoV-2 infecting human heart cells that were grown from stem cells in a lab. Within 72 hours of infection, the virus managed to spread and replicate, killing the heart cells. 

The researchers brought up the particularly alarming possibility that if COVID-19 can infect the heart cells in a laboratory setting, it could possibly infect those specific organs, prompting the need for a "cardiac-specific antiviral drug screen program."

And those concerns are not unwarranted, according to doctors and other researchers who have been observing and studying the wide range of health problems and negative outcomes that appear to come with the not-yet-fully-known territory of the novel virus.

The most common coronavirus symptoms are fever, a dry cough, and shortness of breath — and some people are contagious despite never experiencing symptoms. But as the virus continues to spread, less common symptoms are being reported, including loss of smell, vomiting, and diarrhea, along with a variety of skin problems and harmful neurological effects.

A recent report from Dr. Robert Stevens, M.D., the associate director of the Johns Hopkins Precision Medicine Center of Excellence for Neurocritical Care, said that coronavirus patients are continuously experiencing a wide range of disconcerting effects on the brain.

Some of the neural symptoms, according to Johns Hopkins, include: 

  • Confusion
  • Loss of consciousness
  • Seizures
  • Stroke
  • Loss of smell and taste
  • Headaches
  • Trouble focusing
  • Changes in behavior

"Patients are also having peripheral nerve issues, such as Guillain-Barré syndrome, which can lead to paralysis and respiratory failure," wrote Stevens. "I estimate that at least half of the patients I’m seeing in the COVID-19 units have neurological symptoms."

While medical experts have continuously repeated that more is still being discovered about the virus, Stevens listed some possibilities on how COVID-19, a respiratory illness, is making its way to the brain.

"The first possible way is that the virus may have the capacity to enter the brain and cause a severe and sudden infection. Cases reported in China and Japan found the virus’s genetic material in spinal fluid, and a case in Florida found viral particles in brain cells," Stevens wrote.

He added that viral particles in the brain and spine may occur when the virus enters the body through a patient’s bloodstream or nerve endings.

The second possibility is that the body’s immune system has an overreaction to the virus, causing severe inflammatory responses that cause organ and tissue damage.

The third theory is the erratic physiological changes the disease causes in the body, which involve extremely high fever and low oxygen levels in the blood, result in harmful effects to the brain.

Stevens added that there has been an abnormal observance of blood clotting that has caused some coronavirus patients to suffer strokes. "A stroke could occur if a blood clot were to block or narrow arteries leading to the brain," he said.