COVID-19 can damage lungs so much that ‘only hope’ is transplantation

Case studies and autopsy results confirm that in some cases COVID-19 can cause lung damage so severe that patients need a lung transplant to survive.

In a new study, researchers in Chicago analyzed tissue rejected from patients with COVID-19 who underwent lung transplantation and patients who died from the disease. They found that COVID-19 can destroy the “fundamental framework” of the lungs, which means organs simply cannot recover.

And this means that a patient’s treatment options become very limited.

“We are providing explicit evidence that COVID-19 can cause permanent lung damage in some patients for whom lung transplantation is the only hope of survival,” said Dr. Ankit Bharat, principal investigator of the study. He is chief of thoracic surgery and surgical director of the Northwestern Medicine Lung Transplant Program in Chicago.

His team also discovered unique cells – called KRT17 epithelial cells – in the lung tissue of patients with COVID-19 with irreversible damage. These cells have also been found in patients with end-stage pulmonary fibrosis, a progressive fatal lung disease.

The results, the first of their kind on the issue, were published on November 30 in Scientific translational medicine. To date, eight patients with COVID-19 have received double lung transplants at Northwestern Medicine, the most widely performed health care system in the world.

Dr. Len Horovitz is a pulmonologist at Lenox Hill Hospital in New York. Reading the report, he said it was alarming that COVID-19 can damage the lungs so severely that lung transplantation – a treatment “only for very few patients” – becomes necessary.

Lung transplantation comes with its own dangers, Horovitz added.

“Complications from transplants include infection (maybe even with COVID-19 again), bacterial infection, and possible rejection from the transplanted lungs,” he said.

Speaking in a press release from the northwest, Bharat explained how COVID-19 is believed to be ravaging the lungs.

“Lung progenitor cells needed for healing can repopulate lung wounds by moving along the basic underlying structure of the lung matrix,” he explained. “But when the frame is destroyed, the progenitor cells have nowhere to go and the lungs develop large holes that serve to harbor infections, an observation we also made during difficult transplant surgeries in these patients,” Bharat said.

“Think of it this way: after an earthquake, if a building’s basic structure survives, it can still be renovated. However, if it is leveled, the only option is replacement,” he said. he declares.

According to lead author of the study, Dr. Scott Budinger, professor and chief of pulmonary medicine and critical care at Northwestern, lungs attacked by COVID-19 “also showed striking similarities to the lungs of patients with the disease. of a disease called idiopathic pulmonary fibrosis. “

In this condition, lung tissue becomes “thick and stiff, making it difficult for the body to absorb oxygen,” Budinger said in the press release.

“As in the case of pulmonary fibrosis, we found that COVID-19 led to the recruitment of circulating immune cells called monocytes, which are probably recruited into the lungs to kill the virus,” he added. “In the fibrous lung, these cells also promote the formation of fibrotic scar tissue. These cells can be easily and reliably sampled and could also help mark patients who fail to recover from COVID-19.

There was good news in the report: Researchers also found it safe to perform lung transplants on critically ill patients, even those with infectious causes of lung failure, such as COVID-19. This is new information in the field of transplantation, the Chicago team said.

And there was another silver lining: Despite the use of immunosuppressive drugs in lung transplant patients, the coronavirus responsible for COVID-19 did not appear to be returning.

The team also found that in patients with COVID-19 whose lungs are so damaged that they will not survive without a lung transplant, it is prudent to put them on ECMO (extracorporeal membrane oxygenation) – a machine of survival that does the work of the heart. and the lungs. ECMO can be used for an extended time while leaving the door open for a successful lung transplant, the team said.

The most recent transplant at Northwestern took place on Thanksgiving Day and involved a patient who spent 130 days on ECMO. This is the longest known period of time a patient has spent on ECMO in the world before receiving a transplant.

The best news from the study: Once patients are given new lungs, they tend to recover at a rapid rate, the researchers said.

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