Studies show that COVID-19 pneumonia is different from typical pneumonia

Bacteria that cause pneumonia and viruses like the flu can spread to large areas of the lungs within hours. In modern intensive care units, these bacteria and viruses are usually controlled by either antibiotics or the body’s immune system within the first few days of illness.

However, in a study published in Nature On January 11, researchers at Northwestern Medicine showed that COVID-19 pneumonia was different.

The virus that causes COVID-19 sets up stores in multiple smaller areas of the lung instead of rapidly infecting large areas of the lung. It then hijacks the lungs’ own immune cells and uses them to spread throughout the lungs over days or weeks, much like multiple wildfires that spread throughout the forest. As the infection slowly moves across the lungs, it continuously causes fever, hypotension, and damage to the kidneys, brain, heart, and other organs in COVID-19 patients.

The serious complications of COVID-19 compared to other pneumonia may be associated with long-term illness rather than more serious illness, the study authors said.

This is the first study in which scientists systematically analyzed immune cells in the lungs of patients with COVID-19 pneumonia and compared them with cells of patients with other viral and bacterial pneumonia.

Drug trials to treat newly discovered targets in COVID-19 pneumonia

As a result of detailed analysis, researchers have identified important targets for treating severe SARS-CoV-2 pneumonia and reducing its damage. Targets are immune cells: macrophages and T cells. This study suggests that macrophages (usually the cells responsible for lung protection) can be infected with SARS-CoV-2 and may contribute to the spread of lung-mediated infection. I will.

Northwestern Medicine will test drugs to treat these targets in patients with COVID-19 pneumonia in a clinical trial in early 2021. The drug being tested calms the inflammatory response of these immune cells and allows the process of repairing the damaged lung to begin. ..

Aiming to make COVID-19 like a terrible cold

Our goal is to make COVID-19 mild rather than severe and comparable to a severe cold. “

Dr. Scott Budinger, Study co-author, CNorthwestern University, Feinberg School of Medicine, Northwestern Medicine Lung and Emergency Medicine Director

“This effort truly represents the’moonshot’in the COVID-19 study,” said Feinberg, a professor of lung and emergency medicine, co-chief author of the study, and ICU medicine in Northwestern Medicine. Dr. Richard Wandalink, director, said.

It is unlikely that COVID-19 will disappear completely

COVID-19, like influenza, is unlikely to go away even if many of the population are vaccinated, senior professor of lung and emergency medicine in Feinberg and doctor of northwestern medicine. Co-author Dr. Bensinger said.

“Already, researchers at Northwestern University and elsewhere have predicted the mechanism by which this rapidly mutating RNA virus evades current vaccines,” Singer said. “This study helps develop treatments that reduce the severity of people who develop COVID-19.”

Mortality of COVID-19 patients on ventilator lower than that of normal pneumonia patients

The study also found why patients using a COVID-19 ventilator had a lower mortality rate than patients using a ventilator for normal pneumonia. A severe lung fire (normal pneumonia) increases the risk of death. Patients with COVID-19 pneumonia have been ill for a long time, but lung inflammation is less severe than normal pneumonia.

“Patients with COVID-19 are carefully managed and can be overcome if the health care system is not overwhelmed,” Budinger said. “These patients are very ill. It takes a really long time for them to get better. But with enough beds and health care providers, the mortality rate can be kept at 20%. When the system is overwhelmed, the mortality rate can increase up to 40 times.%. “

In this study, scientists performed a high-resolution analysis of lung fluid in 86 COVID-19 patients with mechanical ventilation and 256 patients with mechanical ventilation with other types of pneumonia. Compared with lung fluid. Due to safety concerns, only a handful of groups around the world analyzed the immune response in the lungs of COVID-19 patients. As a result, important information about what is killing patients with severe COVID-19 was missing.

Northwestern scientists who have been studying pneumonia for years are ready for COVID lung research

The work done at the Northwestern Medicine is unique because Wunderink and colleagues have been studying pneumonia for years before the pandemic. As a result, in the event of a COVID-19 pandemic, fluids are safely and systematically collected from the lungs of these patients and are ready to be compared with fluids collected from other ICU patients with pneumonia collected prior to the pandemic. It’s ready. This research infrastructure allowed us to show how pneumonia in patients with COVID-19 differs from other pneumonia and, more importantly, how it differs.

Scientists removed cells from the patient’s lung fluid and examined the RNA and proteins they express so that they could identify how these immune cells cause inflammation.

“This level of resolution could not have been achieved without direct sampling of lung fluid,” said Feinberg, a co-lead author of the study, an assistant professor of lung and emergency medicine, and a physician in northwestern medicine. Dr. Alexander Michelin said.

The complex nature of the study, in which samples from patients were analyzed with the most sophisticated techniques available at Northwestern University’s state-of-the-art laboratory, required the collaborative efforts of more than 100 researchers.