Danger Dust

The UVA researchers, led by Jie Sun, Ph.D., found that COVID-19 infection can cause sweeping changes in immune cells inside the lung tissues, promoting scarring and driving ongoing inflammation even after the initial infection has passed. This ongoing inflammation, they believe, drives the lasting respiratory symptoms, such as cough and difficulty breathing, associated with long COVID.

The new research from Sun and his colleagues indicates that doctors may be able to halt this chronic inflammation using a class of drugs, including baricitinib, that are already used to treat rheumatoid arthritis. The anti-inflammatory drugs previously received emergency authorization from the federal Food and Drug Administration to treat the uncontrolled inflammation seen in severe COVID-19 infections.

The UVA researchers looked at cell samples collected from the lower airways of both lab mice and human patients.

In both cases, they found that immune cells known as 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 infection had passed.

The macrophages, the researchers found, had flooded into the lungs in abnormal numbers and were promoting tissue scarring. The T cells, meanwhile, were pumping out a substance called interferon that spurs continued inflammation.