news.virginia.edu
“Our study identified a root cause of the respiratory complication of long COVID by performing comparative analysis of both clinical samples and a relevant animal model,” said Sun, of UVA’s Carter Center for Immunology Research and Division of Infectious Diseases and International Health. “We hope that the identification of the ‘driving’ mechanisms will help to rationally design clinical studies repurposing those FDA-approved drugs for respiratory long COVID soon.”
Long COVID is estimated to affect more than 60 million people globally. For these patients, a COVID-19 infection can become a prolonged ordeal, with symptoms lasting weeks, months or even years. Symptoms of long COVID can range from uncomfortable to debilitating; for example, respiratory symptoms can include shortness of breath, chest pain and even chronic lung scarring known as interstitial lung disease.
Prior research into long COVID has focused on patients’ blood, but Sun and his team investigated the changes occurring in the lung tissue. UVA researchers looked at cell samples collected from the lower airways of both lab mice and human patients. In both cases, they found immune cells – macrophages and T cells – had gone haywire and were having faulty, harmful interactions. These cells normally help the body fight off the disease, but, in this case, they never stopped fighting, even after the initial COVID-19 infection had passed.
The macrophages, the researchers found, flooded into the lungs in abnormal numbers and promoted tissue scarring. The T cells meanwhile, pumped out a substance called interferon that spurs continued inflammation.