TUESDAY, March 19, 2024 (HealthDay News) -- Fears that Long COVID patients might end up with long-term, potentially deadly lung scarring are unfounded, a new study concludes.

The same team have come up with a blood test that could potentially spot those Long COVID patients whose lungs are likely to recover well, and those whose lungs may not.

According to researchers at the University of Virginia Health (UVA) System, about 30% of people who develop COVID-19 will go on to develop symptoms of Long COVID.

Some patients develop a stiffening or scarring of lung tissue as part of COVID or its aftermath.

Could this scarring tip over to become progressive pulmonary fibrosis -- a syndrome where lung scarring progresses relentlessly over time, impeding breathing?

To find out, the UVA Health team tracked the lung health of 16 people who'd been hospitalized with severe COVID-19. Fourteen of them had symptoms so severe that they'd needed a ventilator to breathe.

Some of these symptoms continued even after they'd been discharged from the hospital, a sign that Long COVID had set in.

Six months later, some patients' lungs had recovered, while others continued to suffer lung trouble, including pulmonary fibrosis.

Blood tests that tracked levels of immune cells called monocytes were found useful in predicting whose lungs would recover and whose wouldn't, the researchers said. The lungs of folks with low levels of monocytes in their blood samples took longer to bounce back from COVID-19.

These people also had worse symptoms, suggesting that a monocyte-focused blood test might help predict who'll develop Long COVID and who won't.

There was more good news from the study: The kind of damage that COVID and Long COVID appear to inflict on immune cells is very different from that seen among patients with pulmonary fibrosis, the researchers said.

The findings were published recently in the journal Frontiers in Immunology.

“Idiopathic pulmonary fibrosis is progressive and kills patients within three to five years,” noted lead researcher Dr. Catherine Bonham. She's a pulmonary and critical care expert who serves as scientific director of UVA Health’s Interstitial Lung Disease Program.

“It was a relief to see that all our COVID patients, even those with long-haul symptoms, were not similar" to people with idiopathic pulmonary fibrosis, she said in a UVA Health news release.

“We are excited to find that people with long-haul COVID have an immune system that is totally different from people who have lung scarring that doesn’t stop,” Bonham said. “This offers hope that even patients with the worst COVID do not have progressive scarring of the lung that leads to death.”

She stressed that the study's small size means more research needs to be done.

“We are only beginning to understand the biology of how the immune system impacts pulmonary fibrosis,” Bonham said.

More information

Find out more about idiopathic pulmonary fibrosis at the American Lung Association.

SOURCE: UVA Health, news release, Jan. 15, 2024