DNA Explainer: All you need to know about source of life-threatening blood clots in COVID-19 patients

Even as people have been fighting the COVID-19 virus, the after-effects of the disease even after fully recovering from it has sometimes proved more fatal. In India, we saw some patients suffering from black or white fungus after recovering from COVID-19 but losing their battle or organs to the fungus.

Now scientists in the European country of Ireland have identified how some COVID-19 patients can develop life-threatening clots. The researchers from RCSI University of Medicine and Health Sciences, however, said the findings could lead to therapies that prevent it from happening.

Dr Jamie O'Sullivan, the study's author and research lecturer within the Irish Centre for Vascular Biology at RCSI, said that the research helps provide insights into the mechanisms that cause severe blood clots in patients with COVID-19. It is critical to developing more effective treatments, she said.

Previous research has established that blood clotting is a significant cause of death in patients with COVID-19. The work has been published in the Journal of Thrombosis and Haemostasis. 

Why clotting happens?

The researchers analysed blood samples that were taken from patients with COVID-19 in the Beaumont Hospital Intensive Care Unit in Dublin.

They found that the balance between a protein that causes clotting, called von Willebrand Factor (VWF), and its regulator, called ADAMTS13, is severely disrupted in patients with severe COVID-19.

When compared to control groups, the blood of COVID-19 patients had higher levels of the pro-clotting VWF molecules and lower levels of the anti-clotting ADAMTS13.

The researchers also identified other changes in proteins that caused the reduction of ADAMTS13.

VWF is a large, sticky adhesive-like protein that helps to bind platelets within the blood, preventing people from bleeding excessively.

The researchers found in patients with COVID-19, VWF was really elevated, five to six fold above normal levels.

The researchers then looked at why the levels were so elevated and could they reduce it or use it as a therapeutic for patients.

There was also a reduced level of another protein or enzyme in the blood that would usually help to regulate blood clotting, know as ADAMTS13.

The level of this anti-clotting is low in the blood of patients with COVID-19 creating clotting complications in patients with severe infection.