Researchers May Have Discovered the Root Cause of Long COVID Syndrome

New evidence shows that patients with Lung COVID syndrome still have higher blood clotting readings, which may help explain their lingering symptoms, such as decreased physical fitness and fatigue.

The study, led by researchers at RCSI University of Medicine and Health Sciences, is published in the Journal of Thrombosis and Haemostasis.

Previous work by the same group studied the dangerous clotting observed in patients with severe acute COVID-19. However, much less is known about Lung COVID syndrome, where symptoms can persist for weeks to months after the initial infection has cleared, affecting an estimated millions of people worldwide.

The researchers examined 50 patients with symptoms of lung COVID syndrome to better understand whether there is abnormal blood clotting.

They found that coagulation markers were significantly elevated in the blood of patients with lung COVID syndrome compared to healthy controls. These clotting markers were higher in patients requiring hospitalization with their first COVID-19 infection, but they also found that even those who were able to manage their disease at home still had persistently high clotting markers.

The researchers noted that higher clotting was directly linked to other symptoms of Lung COVID syndrome, such as decreased physical fitness and fatigue. Although the markers of inflammation had all returned to normal levels, this increased clotting potential was still present in lung COVID patients.

“Since coagulation markers were elevated while inflammatory markers returned to normal, our results suggest that the coagulation system may be involved in the cause of Lung COVID syndrome,” said Dr. Helen Fogarty, lead author of the study, ICAT Fellow and PhD student at the Irish Center for Vascular Biology in the RCSI School of Pharmacy and Biomolecular Sciences.

This work was funded by the Welcome Trust, the Health Research Board (HRB) Irish Clinical Academic Training (ICAT) program and the HRB-funded Irish COVID-19 Vasculopathy Study (ICVS). The work was also supported by a philanthropic grant from the 3M Foundation to RCSI University of Medicine and Health Sciences in support of COVID-19 research.

“Understanding the cause of a disease is the first step to developing effective treatments,” said Professor James O’Donnell, director of the Irish Center for Vascular Biology, RCSI and consultant hematologist at the National Coagulation Center at St James’s Hospital. , Dublin.

“Millions of people are already dealing with the symptoms of Lung COVID syndrome, and more people will develop Lung COVID as infections continue to occur among the unvaccinated. It is imperative that we continue to study this condition and develop effective treatments.”

Reference: “Persistent Endotheliopathy in the Pathogenesis of Long-Term COVID Syndrome” by Helen Fogarty, Liam Townsend, Hannah Morrin, Azaz Ahmad, Claire Comerford, Ellie Karampini, Hanna Englert, Mary Byrne, Colm Bergin, Jamie M. O’Sullivan, Ignacio Martin -Loeches, Parthiban Nadarajan, Ciaran Bannan, Patrick W. Mallon, Gerard F. Curley, Roger JS Preston, Aisling M. Rehill, Dennis McGonagle, Cliona Ni Cheallaigh, Ross I. Baker, Thomas Renné, Soracha E. Ward, James SO’ Donnell, investigators of the Irish COVID-19 Vasculopathy Study (iCVS), Aug 10, 2021, Journal of Thrombosis and Haemostasis.
DOI: 10.1111/jth.15490