Northwestern Medicine investigators have created a novel blood test that identifies adults who may be at increased risk of developing severe respiratory illnesses, including chronic obstructive pulmonary disease (COPD), according to a recent study published in the American Journal of Respiratory and Critical Care Medicine.
“If we can identify biologic pathways that could be interfered with in patients who show risk factors for future bad respiratory events, we could change the game and intercept lung disease before it’s clinically apparent,” said Ravi Kalhan, MD, ‘06 MS, the Louis A. Simpson Professor of Pulmonary Medicine and associate dean of faculty affairs, who was senior author of the study.
COPD is the third-leading cause of death worldwide, according to the World Health Organization. The disease is commonly caused by a history of smoking and increases a person’s risk of developing additional health problems, including lung cancer and cardiovascular issues.
While COPD isn’t curable, treatments may help improve quality of life, however there are no established methods for detecting lung function decline early to prevent potential severe disease, according to Kalhan.
“We know that people who are experiencing accelerated decline in their lung function are at risk of developing severe COPD or having other health problems in the long run. If we could figure out who those people are, it would open the doors of possibilities for how we can think about blocking this unfavorable trajectory in their lung function,” said Kalhan, who is also a professor of Preventive Medicine in the Division of Epidemiology.
Using blood sample data from more than 2,400 participants enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study, the investigators used a technique called discovery proteomics to identify 32 unique protein expression levels in the blood samples from individuals with lung function decline compared to those without.
These 32 proteins were then compiled into a proteomic risk score created by Kalhan’s team. The investigators then tested this risk score in two other patient cohorts, one from the COPDGene Study and the other from the U.K. Biobank, to examine associations with future respiratory morbidity and mortality.
Overall, adults with higher risk scores had a 17 percent increased risk of requiring hospital care for respiratory illness, an 84 percent increased risk of developing COPD, and an 81 percent increased risk of dying from a respiratory disease.
Adults with higher scores also had a 10 percent increased risk of experiencing respiratory exacerbations, such as a cough, mucus, or shortness of breath, that required additional treatment.
“We think this is step one to finding out what causes COPD in the long run. It’s innovative in the sense that it takes a super-important clinical measure that no one can actually determine easily and synthesizes it into a blood test that now we know predicts bad outcomes,” said Kalhan, who is also co-director of the Northwestern University Clinical and Translational Sciences (NUCATS) Institute’s Center for Education and Career Development.
Kalhan said his team is currently validating their method to better identify patients at risk for COPD and medically attended respiratory illnesses that require healthcare contact or intervention.
“If we can do the hard work of figuring out what the causal roles of those proteins are and how they function and how this risk is conveyed, we can actually think about targets for interception of chronic lung disease before it becomes a problem,” Kalhan said.
Co-authors of the study included Xiaoning Huang, PhD, research assistant professor of Medicine in the Division of Cardiology; Shaina Alexandria, PhD, assistant professor of Preventive Medicine in the Division of Biostatistics; Anthony Esposito, MD, assistant professor of Medicine in the Division of Pulmonary and Critical Care; and Sadiya Khan, ‘09 MD, ‘14 MSc, ’10, ’12 GME, the Magerstadt Professor of Cardiovascular Epidemiology.
This work was supported in part by National Heart, Lung, and Blood Institute grant R01 HL122477 (CARDIA Lung Study).
