New biomarker may predict lung disease progression

Researchers have identified a new biomarker that may help identify patients at higher risk for a deadly lung disease and lead to better treatments.
A process initiated in white blood cells known as neutrophils may lead to worse outcomes for some patients with chronic obstructive pulmonary disease (COPD), researchers said.
The discovery may help identify patients at higher risk for COPD progression, who might also show little benefit from standard treatments, they said.
COPD is a type of obstructive lung disease characterised by long term poor airflow.
"Our study found that a recently identified form of neutrophil behaviour called neutrophil extracellular trap (NET) formation is present in the lungs of COPD patients, and may weaken their ability to eat and kill bacteria," said James D Chalmers from University of Dundee in Scotland.

Researchers found that when NET formation weakens neutrophils' bacteria-fighting capability, patients experience more frequent chest infections and worse lung function and quality of life.

"This marker may help us identify patients at higher risk of disease progression. And it identifies a subset of patients who may need treatments other than corticosteroids," said Chalmers.
"Our data show that inhaled steroids may even exacerbate NETs, so we need to identify new COPD treatments and discover whether inhibiting NET formation will result in improved clinical outcomes for patients with COPD," he said.
Researchers recruited 141 patients with stable COPD for the study. Sputum and blood were collected at the beginning of the study, during acute COPD exacerbations, and at the end of exacerbations.

NETs were measured using a validated enzyme-linked immunosorbent assay targeting specific DNA associated NET/protein complexes, researchers said.
The amount of NET complexes in the lungs of patients in the study was directly related to the severity of their COPD and the risk of exacerbations. NETs increased significantly during exacerbations that did not respond to corticosteroid treatment, they said.
Neutrophilic airway inflammation has been known for some time to be a characteristic feature of COPD, researchers said.
NETs were discovered as an essential part of innate immune response to infection approximately 10 years ago, and scientists are only beginning to understand how NETs impact disease outcomes, they said.