Research suggests safer, effective way to improve stroke treatments

A team of researchers has demonstrated that a drug in combination with an enzyme that helps dissolve clots may improve stroke outcomes by reducing these complications and increasing its efficacy in opening blood vessels.

The standard of care for treating strokes caused by blood clots involves the therapeutic infusion of tissue plasminogen activator (tPA) -- an enzyme that helps dissolve clots, which can help to dissolve the clots and restore blood flow.

The study was published in the journal Blood.

Working with animal models, the researchers at Joslin Diabetes Center in Massachusetts, United States have demonstrated the potential of giving a drug in combination with tPA that might improve stroke outcomes.

"Drugs that target a protein called plasma kallikrein, as well as an activator protein called factor XII, "may provide the opportunity to make tPA safer by reducing these complications and increasing its efficacy in opening blood vessels," said study author Edward Feener.

About 8, 00,000 people in the United States suffer a stroke each year, and about 87% are ischemic strokes, in which blood flow is blocked by a clot.

Lead author Fabrício Simao with his colleagues demonstrated that tPA boosts the activity of plasma kallikrein in both human and mouse plasma.

They experimented with mouse models in which blood clots were induced in the brain and then treated with tPA.

Animals were also given a plasma kallikrein inhibitor and were genetically modified to produce lower amounts of the protein.

It showed significantly less bleeding, brain swelling and damaged brain areas than control animals without plasma kallikrein blockade.

Plasma kallikrein is known to activate the kallikrein kinin system, a pathway that has been implicated in stroke complications including brain swelling and breakdown of the blood-brain barrier.

These new findings suggest additional potential therapeutic opportunities for plasma kallikrein inhibitors in thrombolytic therapy.