Autopsies performed on people who died from Covid-19 have revealed "peculiar and unexpected" lung damage caused by SARS-CoV-2. The new study, reported in the Lancet's journal eBioMedicine today, could help to explain why people who recover from the disease still suffer from lingering symptoms long after first falling sick with the disease, a phenomenon dubbed “long-Covid.”
Researchers from King’s College London, the University of Trieste, and the International Centre for Genetic Engineering and Biology in Italy analyzed the organs of 41 patients who died of Covid-19 at the University Hospital of Trieste in Italy between February and April 2020.
They found that just under 90 percent of the patients showed unusual characteristics in the lungs that were different from the ones you’d typically see in a straight-forward pneumonia death. For starters, the blood vessels of the lungs were riddled with extensive blood clotting. A study released earlier this week also revealed why blood clots are a common feature of Covid-19, suggesting the disease triggers the release of autoimmune antibodies that cause blood clotting.
Secondly, they also noticed many of the lung cells were abnormally large and had many nuclei. They argue this is the result of the fusion between different cells into single large cells, caused by a process known as syncytia.
Finally, the autopsies revealed that the genetic material (RNA) of the virus could still be found lurking in the single-celled layer that lines the blood vessels and the surface epithelial cells in the lung. When it comes to understanding long-term complications of Covid-19, this could be an important piece of the puzzle, say the researchers.
“The findings indicate that Covid-19 is not simply a disease caused by the death of virus-infected cells, but is likely the consequence of these abnormal cells persisting for long periods inside the lungs,” Mauro Giacca, a professor at King’s College London who co-led the work, said in a statement.
Scientists and medical practitioners are still struggling to come to grips with the exact nature of "long-Covid," but an increasing amount of evidence suggests how and why some people continue to suffer from a wide array of side effects of Covid-19 even weeks or months after the initial phase of the illness, including tiredness, a lack of concentration, loss of smell and taste, so-called "brain fog,” and difficulty breathing.
The researchers conclude with a discussion about how their study could help pave the wave for new treatments for Covid-19. For example, they say that they are searching for a possible drug that could block the viral spike protein that causes cells to fuse, which could stop the formation of unusually clumped large cells. They’re also investigating whether or not these abnormal cells affect blood clotting and inflammation.