Enzyme may help dissolve blood clots in stroke patients

blood clots

Cardiovascular scientists from the KU Leuven Laboratory for Thrombosis Research (Campus Kulak Kortrijk) have shown that the ADAMTS13 enzyme can dissolve blood clots that block the blood flow to the brain. Their discovery may open up new possibilities for the treatment of stroke patients.

For proper functioning of our brain, a continuous blood supply to the brain is essential. When a blood clot blocks an artery that supplies blood to the brain, an ischemic stroke occurs. This type of stroke often causes permanent brain damage. Ischemic strokes are among the leading causes of death and permanent disability in Western society.

Only one treatment is currently available to dissolve blood clots in the brain: administering the substance t-PA in time. Unfortunately, this treatment only works in a fairly limited number of patients.

Professor Simon De Meyer and Frederik Denorme from the KU Leuven Laboratory for Thrombosis Research have now discovered that stroke-causing blood clots can be significantly different in terms of composition, which explains why the t-PA doesn’t always work.

“The key is in the blood proteins”, Professor De Meyer explains. “Some blood clots are rich in fibrin, and these clots can be broken down with t-PA. Others clots, however, contain relatively large amounts of a protein called von Willebrand Factor (VWF). This protein is insusceptible to t-PA.”

With this knowledge, the researchers went one step further by using ADAMTS13, an enzyme that, unlike T-PA, has an impact on von Willebrand Factor. “We administered ADAMTS13 to mice with VWF-rich blood clots”, Professor De Meyer continues. “We noticed that it made the clot in the brain dissolve quickly. The rapid breakdown of a blood clot can restore the blood flow to the brain and limit brain damage.”

Given the current limitations in the treatment of stroke patients, new insights into breaking down blood clots are particularly valuable. Further research will have to show whether the study can help improve therapies for patients who’ve had ischemic stroke.

Click here to read the study “ADAMTS13-mediated thrombolysis or t-PA resistant occlusions in ischemic stroke in mice” in Blood.