Infants with cystic fibrosis may breathe better by inhaling hypertonic saline, according to a randomized controlled trial conducted in Germany and published in the American Journal of Respiratory and Critical Care Medicine.
In “Preventive Inhalation of Hypertonic Saline in Infants with Cystic Fibrosis (PRESIS): A Randomized, Double-blind, Controlled Study,” Mirjam Stahl, MD, and co-authors describe a study of 40 young infants (average age three months at enrollment) with CF. The babies were randomly assigned to receive hypertonic saline (saline with a 6% salt concentration) or isotonic saline. They were followed for 12 months.
Previous studies in mice found that the salt content of hypertonic saline decreased mucus plugging that leads to airway obstruction and repeated infections. Other studies found hypertonic saline benefited older children and adults with CF.
“Several studies from teams worldwide investigating infants and preschool children with CF diagnosed early by newborn screening revealed that CF lung disease starts in the first months of life, leaving only a narrow window of opportunity for preventive therapeutic interventions,” said Dr. Stahl, lead study author and a pediatric pulmonologist at the Cystic Fibrosis Centre and the Translational Lung Research Center at the University of Heidelberg. “Our results show that treatment with hypertonic saline in infants with CF is safe from diagnosis onwards and suggest this preventive therapy benefits lung function and improves thriving.”
The researchers also tested whether lung clearance index and chest magnetic resonance imaging (MRI) could be safely performed on the infants and serve as quantitative outcome measures of early lung disease.
Lung clearance index measures how well air is flowing through the lungs. Mucus obstruction of the smallest airways is one of the earliest features of CF lung disease, and lung clearance index can detect changes in breathing caused by mucus plugging. MRI can detect early abnormalities in lung structure.
The authors report that both procedures could be safely performed in the infants and were well tolerated, though lung clearance index in this particular study provided a better yardstick to measure the benefits of this treatment.
After one year, the infants receiving the hypertonic saline had a better lung clearance index. Furthermore, they gained significantly more weight (500 grams higher mean weight after one year of treatment) and height (1.5 centimeters higher mean height after one year of treatment). The weight gain confirmed previous studies of hypertonic saline in a mouse model for CF lung disease.
Pulmonary exacerbation rates and adverse events between the treatment groups were similar.
Study limitations include the fact that isotonic saline (sodium chloride concentration: 0.9%) is not a true placebo because it may, itself, have therapeutic benefits. The authors added that the infants were followed for only one year, so whether hypertonic saline therapy is beneficial long term is unknown.
The study is believed to be the first randomized controlled trial in infants with CF using innovative, sensitive outcome parameters such as lung clearance index and MRI in this challenging age group.
“This study paves the way for controlled testing of novel treatment strategies in infants,” said senior study author Marcus A. Mall, MD, director of the Department of Pediatric Pulmonology and the Cystic Fibrosis Centre at the Charité University Medical Center Berlin of Heidelberg. “It may prove to be a breakthrough in the development of therapies that may prevent, or at least delay, the onset of lung damage in people with CF.”