London, Aug 17 (IANS): Patients with Long Covid syndrome continue to have higher measures of blood clotting, which may help explain their persistent symptoms, such as reduced physical fitness and fatigue, finds a research.

While the dangerous clotting has been observed in patients with severe acute Covid-19, 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.

Researchers from RCSI University of Medicine and Health Sciences in Ireland, 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. These clotting markers were higher in patients who required hospitalisation with their initial 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.

In the study, published in the Journal of Thrombosis and Haemostasis, the team 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 the Long Covid patients.

"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," said lead author Dr Helen Fogarty, doctoral student at the Irish Centre for Vascular Biology in the RCSI School of Pharmacy and Biomolecular Sciences.

In a separate study, a team from the University of Cambridge, in the UK, found that small protein molecules called cytokines could have a link to the Long Covid condition, the Daily Mail reported.

Cytokines, which are produced by the body in response to infections, are often found to be lingering in a person's body for months after infection.

They developed a simple new blood test that may determine whether or not Covid-19 survivors will experience long-term symptoms.