Von Willebrand Factor May Hold Key to COVID-19 Severity

The severe course of coronavirus disease 2019 (COVID-19) may be tied to the von Willebrand factor (VWF), according to a new hypothesis out of St. Petersburg University.

VWF is one of the main components of the blood coagulation system. Clotting is a significant part of the deaths from COVID-19. According to the press release, the virus stimulates the development of microdamage on vessel walls. When this happens, the body releases VWF into the blood, which tries to “patch” possible holes, potentially leading to clotting.

VWF may also be the reason why COVID-19 presents itself so differently in each individual, according to the study authors. Even individuals who are of the same age and comparable health may exhibit different symptoms and severity. For example, one patient may require a ventilator whereas another may not feel sick at all. According to the press release, this may be because of different levels of VWF in the blood.

“This protein is synthesized in endothelial cells and platelets, and its main function is to form a framework for platelet adhesion…To date, the way in which the level of VWF is regulated in the blood has not yet been fully studied. However, it is known to be stored in vascular endothelial cells in special organelles, where it secretes in the form of multimers. As soon as some damage to the vessel occurs, then in order to eliminate it, a cascade of blood coagulability is launched in the body, in which VWF takes an active part,” senior research associate at the Laboratory of Amyloid Biology at St Petersburg University Anna Aksenova, PhD, said in the press release.

Large scale research is still necessary, according to the press release. The study authors noted that VWF may explain why chloroquine, a malaria drug, is in preliminary trials as a potential COVID-19 treatment. According to the press release, chloroquine affects the process of autophagy in cells, which helps to regulate the secretion of VWF.

Reference

Complications from COVID-19 may depend on von Willebrand factor in the blood (Press Release), St. Peteresburg University, Russia, July 3, 2020, EurekAlert! Accessed July 7, 2020