How blood factors work together to prevent clotting

Factor V as a synergistic cofactor together with protein S in the inhibition of FXa by TFPI

Dr Josefin Ahnstrom and colleagues at Imperial College London have been awarded a 3-year grant to investigate the components that prevent blood from clotting, including Tissue Factor Pathway Inhibitor (TFPI), protein S and factor V. They aim to determine how protein S and factor V work together to make TFPI more active. TFPI helps stop blood clotting but it does not have a strong effect on its own, protein S improves its ability to stop blood clotting. Recent studies have suggested that factor V also enhances TFPI’s activity. However, the full extent of this enhancement and the processes are unknown. This research will define important anticlotting processes that when compromised will cause clotting. Blood clots can stick to the wall of a blood vessel such as those supplying the heart, and can restrict blood flow resulting in a heart attack. This group is researching a method for preventing blood clotting. This should help inform the development of treatments for those at risk of blood clotting and consequently help to reduce the risk of heart attack.