Moderate Lung Clots May Protect Against Sepsis

A new preclinical study shows that moderate blood clotting in the lungs may actually help protect against sepsis-related acute respiratory distress syndrome (ARDS).

Researchers created lung clots in adult mice using tiny beads and then caused acute lung injury with either lipopolysaccharide or cecal ligation and puncture, common methods to study sepsis and lung damage.

They found that severe lung clots and low platelet counts made sepsis-related lung injury worse and increased death rates. But mild, controlled lung clots reduced lung cell death, lessened lung damage, and improved survival.

This protective effect depended on a protein called Alox15, an enzyme in the blood vessel lining (endothelium). When Alox15 was removed specifically from the endothelium, the benefit of mild clots disappeared, and lung injury became worse.

Conversely, increasing Alox15 in the endothelium using targeted nanoparticles helped reduce the extra damage caused by severe clots, suggesting that boosting this pathway could protect the lungs from serious clot-related injury.