Researchers around the world have been puzzled by a deadly COVID-19 complication. Swollen legs, rashes and sudden death are a result of large and small blood clots. More than 30 percent of COVID-19 patients suffer from blood clots which create lethal blockages in the lungs, kidneys, heart and brain.

Hadassah Prof. Abd Higazi, who heads the Division of Laboratories and Department of Clinical Biochemistry, has revealed the mechanism that causes them. Last year, Higazi and colleagues published a seminal paper in the leading medical journal Blood about Alpha-defensin, a peptide (an amino-acid chain) also called cryptdins.

Dr. Abd Al-Roof Higazi, right, and lab manager Suhair Abdeen at Hadassah University Medical Center.

Higazi discovered that this peptide speeds up the creation of blood clots and prevents their disintegration. This is crucial in understanding what was happening to COVID-19 patients, because existing anticoagulant drugs don't impact Alpha-defensin.

“We took blood samples from patients in Hadassah’s Outbreak Department and found a high concentration of Alpha-defensin,” says Higazi. “The sicker the person, the higher the concentration of this peptide."

Higazi and lab manager Suhair Abdeen are working on a new way to dissolve the blood clots. They are testing colchicine, an oral medication used for gout and Familial Mediterranean Fever. It has succeeded in reducing Alpha-defensin levels and blood clots in mice. They are waiting approval to begin human trials.

Higazi believes if the drug works to reduce blood clots in COVID-19, it will vastly reduce the numbers of patients needing respirators.

“These patients have numerous blood clots in their lungs, preventing normative blood flow,” he explains. “We can also give it to those with mild symptoms to prevent the development of blood clots.”