Inflammation evident in nasal fluid of babies with CF, study suggests
Changes in levels of certain cytokines with infection seen in nostril swabs
Inflammatory molecules that serve as markers of infection or other problems can be measured in the nasal fluid of babies with cystic fibrosis (CF), collected using filter paper placed in a nostril.
Changes in the levels of some of these molecules, using this noninvasive method, were seen in infants “and are associated with intermittent exacerbations of lung disease, viral infections, and exposure to second-hand tobacco smoke,” the scientists wrote.
Their study, “Nasal airway inflammatory responses and pathogen detection in infants with cystic fibrosis,” which was published in the Journal of Cystic Fibrosis.
Potentially easier way of checking health, signs of inflammation in CF babies
People with CF characteristically have inflammation in the airways that can contribute to long-term lung damage. Since lung inflammation in early life can have lasting consequences, it’s important to be able to accurately assess lung inflammation in children with CF.
Current ways of measuring inflammation with CF include blood tests and bronchoalveolar lavage, a procedure where fluid is flushed through the lungs. But both are limited with infants, and bronchoalveolar lavage can be particularly invasive, the researchers noted.
Scientists recently developed an alternative method using filter paper gently inserted into a nostril to collect nasal fluid, which then can be analyzed for markers of inflammation.
Researchers in the U.S. examined this technique, collecting nasal fluid from 34 babies with CF being cared for at centers in Ohio or Indiana. Each child was followed from the first months of life until about one year of age.
Nasal fluid samples were collected at regular checkups and when the babies showed signs of illness or infection; over the course of follow-up, a total of 246 samples were collected. The researchers also collected nasal swabs to check for respiratory viruses, as well as hair samples to confirm chronic exposure to nicotine in cigarette smoke.
They measured levels of several inflammation-related molecules in the samples, then they conducted statistical analyses to look for patterns.
“Ours is the first study to demonstrate the feasibility of nasal cytokine measurement from nasal filter paper in infants with CF,” the researchers wrote. Cytokines are a class of signaling molecules that play a key role in inflammation.
Nasal fluid of CF infants with viral infections had significantly higher levels of inflammatory markers including TNF-alpha, neutrophil elastase (NE), IL-6, and IL-8, and lower levels of another inflammatory marker called IL-17A, results showed. Of note, the most common viral infections were with rhinovirus or enterovirus, viruses that typically cause cold-like symptoms in the general public.
During pulmonary exacerbations, a sudden worsening of lung function usually due to an infection, levels of NE were significantly elevated while IL-17A was significantly decreased. Statistical analyses also showed significant differences in some inflammatory markers based on rates of bacterial or viral infections, and antibiotic use.
Results also suggested that babies exposed to cigarette smoke had higher levels of NE and IL-6, as well as of the anti-inflammatory marker IL-10, in their nasal fluid.
Viral or bacterial infections, or antibiotics likely to alter inflammation
Although specific events like infections were associated with changes in inflammation markers, levels of these molecules in nasal fluid generally didn’t change much over time as the babies grew through infancy. The researchers noted that several of the inflammatory markers were present at high levels even in very young babies with CF.
“Our findings suggest that clinical conditions such as viral infection, antibiotic usage, bacterial infection, or [pulmonary exacerbations] can influence inflammation in infants with CF,” the scientists concluded. “However, pro-inflammatory signatures exist independent of these events,” supporting “prior studies that early inflammation is modified by environmental exposures such as tobacco smoke.”
These findings “may be useful in further studies to correlate inflammation measured non-invasively to lower airway inflammation and progression of CF lung disease,” the scientists concluded.
The lack of a control group without CF was noted as a study limitation by the team.