Researchers at Washington University School of Medicine in St. Louis have identified a gene that limits damage to the lung during acute stress from illness, trauma, or transplant. The findings, published in the Journal of Clinical Investigation, show that defects in the bcl3 gene likely leave some patients more vulnerable to lung injury. The researchers also demonstrated that this critical gene, which is active in bone marrow cells, can prevent lung injury in mice.

Lung injury is a common cause of death among patients with pneumonia, sepsis, or trauma and in those who have had lung transplants. The damage often occurs suddenly and can cause life-threatening breathing problems and rapid lung failure. There are no effective treatments. Patients usually are put on ventilators to give their lungs a chance to heal, but there is little else doctors can do but wait and hope for the best.

According to the researchers, the discovery of this gene lays the groundwork for developing therapies to reduce complications of pneumonia, trauma, and lung transplants.

Infection-fighting white blood cells called neutrophils are the real culprits underlying acute lung injury. When the body makes too many neutrophils, however, they begin to attack healthy tissue, causing even more damage and sometimes even death.

The researchers found that in mice, the bcl3 gene is responsible for how many neutrophils the body produces when the lung is under acute stress. The same gene exists in people.

Mutations in bcl3 have long been associated with the development of leukemia and lymphoma. Only recently has it been found to play a role in inflammation.

Source: Washington University in St. Louis