By Kate Kelland
LONDON (Reuters) – A study of the lungs of people who have died from COVID-19 found persistent and widespread lung damage in most cases and could help doctors understand what is behind an the syndrome is called a ‘long COVID’, in which the patient endures symptoms continuously for many months.
The scientists leading the study said they also found some specific characteristics of SARS-CoV-2, the virus that causes COVID-19, which may explain why it can be as harmful as so.
Mauro Giacca, a professor at King University, said: “The findings indicate that COVID-19 is not simply a disease caused by the death of infected cells, but likely a consequence. of these abnormal cells that persist for a long time inside the lungs. London, co-lead the work.
The research team analyzed tissue samples from the lungs, heart, liver and kidneys of 41 patients who died from COVID-19 at Trieste University Hospital in Italy between February and April 2020.
In a phone interview, Giacca said that, while his team found no clear signs of a viral infection or persistent inflammation in other organs, they did find out. “really large damage to the architecture of the lungs”, with healthy tissues “almost completely replaced by tissue scarring”.
“It is highly predictable that one of the reasons why there are persistent COVID infections is because the lungs (tissue) are so badly damaged,” he told Reuters. “Even if someone recovers from COVID, the damage caused can be enormous.”
There is increasing evidence from around the world that a small proportion of people who have already been infected with COVID-19 and recover from their initial infection may experience a persistent range of symptoms including fatigue. fatigue, brain fog and difficulty breathing. This is commonly referred to as a “long COVID”.
Giacca said that nearly 90% of the 41 patients had some specific characteristics of COVID-19 compared with other forms of pneumonia.
One is a patient with a blood clot in the pulmonary and venous arteries. Another cause is that a number of lung cells are abnormally large and have multiple nuclei – the result of fusing different cells into single large cells in a process called syncytium.
Research published in the Lancet eBioMedicine also found that the virus itself persisted in many types of cells.
“The presence of these infected cells can cause important structural changes in the lungs that can persist for several weeks or months and may eventually account for ‘COVID pulls,'” Giacca said. long’.
(Reported by Kate Kelland, edited by Gareth Jones)