New evidence shows that patients with long Covid continue to have higher measures of blood clotting, which may explain persistent symptoms, including reduced physical fitness and fatigue.
The study, led by researchers from RCSI (Royal College of Surgeons in Ireland) 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, far less is known about long Covid syndrome, where symptoms can last weeks to months after the initial infection has resolved and is estimated to affect millions of people worldwide.
The work, led by @IrishCtrVascBio @RCSIPharmBioMol researchers, was funded by the @wellcometrust, @ICATProgramme, @hrbireland Covid-19 Rapid Response award and a philanthropic grant from the @3M Foundation.
The research is published in @JTHjournal.https://t.co/02oAtJebWNAdvertisement— RCSI (@RCSI_Irl) August 16, 2021
The researchers examined 50 patients with symptoms of long Covid syndrome to better understand if abnormal blood clotting is involved.
They discovered that clotting markers were significantly elevated in the blood of patients with long Covid syndrome compared with healthy controls.
Researchers said these clotting markers were higher in patients who required hospital admission following their Covid-19 infection, but they also found that even those who were able to manage their illness at home still had persistently high clotting markers.
The researchers observed that higher clotting was directly related to other symptoms of long Covid syndrome, such as reduced physical fitness and fatigue.
Even though markers of inflammation had all returned to normal levels, this increased clotting potential was still present in long Covid patients, they said.
Dr Helen Fogarty, the study’s lead author, and PhD student at the Irish Centre for Vascular Biology, said: “Because clotting markers were elevated while inflammation markers had returned to normal, our results suggest that the clotting system may be involved in the root cause of long Covid syndrome.”
Professor James O’Donnell, director of the Irish Centre for Vascular Biology, RCSI and consultant haematologist in St James’s Hospital in Dublin, said: “Understanding the root cause of a disease is the first step toward developing effective treatments.
“Millions of people are already dealing with the symptoms of long Covid syndrome, and more people will develop long Covid as the infections among the unvaccinated continue to occur.
“It is imperative that we continue to study this condition and develop effective treatments.”
The work was funded by the Wellcome Trust, the Health Research Board (HRB) Irish Clinical Academic Training (ICAT) programme as well as the HRB-funded Irish Covid-19 Vasculopathy Study (ICVS).