Inhaled Hypertonic Saline Eases CF Symptoms and Helps Infants Breathe Easier, Trial Finds

Inhalation of hypertonic saline can help babies with cystic fibrosis to breathe better and relieve CF symptoms, according to a new trial. Researchers safely measured lung airflow in infants and observed an improved lung clearance after one year of treatment.

Trial results were published in the American Journal of Respiratory and Critical Care Medicine, in an article titled “Preventive Inhalation of Hypertonic Saline in Infants with Cystic Fibrosis (PRESIS): A Randomized, Double-blind, Controlled Study.”

CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, causing the loss of CFTR protein, which is a chloride ion transporter. Chloride ion transportation is important to maintaining the balance between water and salt on the cell surface; CFTR loss disturbs this balance and results in thickening of the cell-surface mucus that may cause airway obstruction and increase the risk of infections.

Previous studies in mice have shown hypertonic saline to be of benefit, reducing the thickness of mucus in the cell surface of the lungs. Of note, a hypertonic saline is a solution containing salt concentrations that are greater than the physiologic concentration (0.9%) found in cells.

In fact, inhalation of 6% hypertonic saline is considered an effective maintenance therapy for CF adults and children (older than 6), as it improves mucociliary clearance and lung function, and reduces pulmonary exacerbations.

This study, funded by the German Federal Ministry of Education and Research and the Dietmar Hopp Foundation, assessed if hypertonic saline inhalation is an effective preventive treatment in infants with CF, and if existing measurement strategies are safe.

The double-blinded Phase 2 trial PRESIS (NCT01619657) enrolled 42 newborns and infants (up to 4 months of age) who inhaled either hypertonic saline (6% sodium chloride) or isotonic saline (0.9% sodium chloride; a control solution), twice daily for one year.

Lung airflow and lung structure were assessed through the lung clearance index (that measures how well air is flowing through the lungs) and chest magnetic resonance imaging (MRI), respectively.

Results showed that both saline solutions were safe and well-tolerated by the infants.

At one year, the change in the lung clearance index was greater in CF infants treated with hypertonic saline (a decrease of 0.6), suggesting improved airflow in the lungs compared with isotonic saline treatment (a decrease of 0.1).

Poor weight gain and growth are common to CF patients, due to thicker mucus in the intestines. The researchers found that infants treated with hypertonic saline also experienced significant weight gain (500 grams, or 1.1 pounds) and height gains (1.5 centimeters or just under an inch) compared with controls. These results confirmed previous studies, showing increased weight gain in mice treated with hypertonic saline.

Of note, pulmonary exacerbations, adverse events, and MRI scores were similar between the two study groups.

“[P]reventive treatment with inhaled hypertonic saline is safe and well tolerated, and has therapeutic benefits on lung function and thriving in the first year of life” in infants with CF, the researchers wrote.

“CF lung disease starts in the first months of life, leaving only a narrow window of opportunity for preventive therapeutic interventions,” Mirjam Stahl, MD, the study’s lead author and pediatric pulmonologist at the Translational Lung Research Center at the University of Heidelberg, said in a press release.

“Prevention, or at least delay, of the onset and progression of CF lung disease may be a promising therapeutic strategy,” Stahl added.

The study also showed that the lung clearance index is a safe and adequate approach to assess the benefits of treatment in CF infants.

“We demonstrated that early studies are feasible in this challenging age group using innovative, sensitive outcome parameters such as lung clearance index,” Stahl concluded, adding that “treatment with hypertonic saline in infants with CF is safe from diagnosis onwards, and our results suggest this preventive therapy benefits lung function and improves thriving.”