A potential biomarker for the detection of non-allergic, childhood asthma may offer new hope for clinicians and patients. A study of the protein urinary club cell 16’s (uCC16) role in the condition indicated that children with non-allergic asthma had lower levels of uCC16 compared to non-asthmatic children. The research is significant because there are currently no biomarkers for detecting this form of asthma.
The Vanderbilt University study, “Urinary Club Cell 16 as a Possible Biomarker for Childhood Asthma and Asthma Phenotypes,” was recently published in the journal, CHEST. Specifically, researchers found that urinary levels are inversely associated with recurrent wheeze after lower respiratory tract infections among infants.
“When we all think about allergic asthma, probably for most of us, we have a clear sense of what that is. A clinical image comes to mind. It goes hand in hand with biomarkers and a few different flavors,” said Kathleen Hiltz, MD, a clinical fellow in the department of medicine’s division of allergy, pulmonology and critical care medicine at Vanderbilt University Medical Center in Nashville.
Researchers analyzed urinary uCC16 levels in 150 children, including those with atopic asthma, non-atopic asthma and non-asthmatic controls. Adjusted median uCC16 levels were 76 ng for the atopic asthma group, 83 ng for the nonatopic group and 101 ng for the control group. UCC16 is a protein that can be detected in urine and is a potential biomarker for lung diseases. The study utilized data from the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure (INSPIRE) cohort, which included healthy term infants enrolled between 2012 and 2013. The cohort was designed to oversaturate for viral season, enrolling infants born from June to December to capture their first RSV season.
To date, non-allergic asthma has been defined by the absence of biomarkers, Dr. Hiltz said.
“We do not today have any real biomarkers for non-allergic asthma to identify clinically in a clinic setting, to identify for clinical trials or to potentially direct targeted therapeutics the way that the allergic asthma phenotype has,” Dr. Hiltz said. “A biomarker in the space would be very useful.”
Although the study did not find statistically significant differences between asthma phenotypes and uCC16 levels, the trend suggests a potential protective effect of higher urinary CC16 levels against developing allergic asthma. Dr. Hiltz noted that urinary biomarkers are practical for pediatric patients as they do not require blood draws.
“This is a protein that’s secreted in robust quantities by bronchial epithelial cells. It likely has anti-inflammatory, antioxidant, immunomodulatory roles,” Dr. Hiltz said. “It can be measured in bronchial washings, in sputum, in serum, and it’s renally excreted.”
Researchers plan to expand the study to include more data and refine asthma phenotype classifications with atopy assessments at age six. This expansion aims to address potential misclassifications from earlier assessments at age three.
