Inhalation of hypertonic saline improves lung function and growth in infants with cystic fibrosis (CF), according to the results of the PRESIS randomized controlled trial.

"Our study supports that a greater focus should be put on the development of preventive therapies in infants (beyond hypertonic saline) to exploit the window of opportunity created by CF newborn screening to improve life expectancy and quality of life of people with CF," Dr. Marcus A. Mall.  Potentially reversible abnormalities are already present in young infants with CF. Preventive interventions starting in early infancy could delay or prevent reversible lung damage in these infants.

Dr. Mall and colleagues explored the feasibility, safety and initial efficacy of preventive inhalation of hypertonic saline in 42 young infants (age range, 0.09-0.41 year) with CF, using lung clearance index (LCI), a sensitive measure of abnormal lung function , disease progression and response to therapy, and MRI, which detects early abnormalities in lung structure and perfusion, as outcome measures.

Chest MRI

Chest MRI was abnormal at baseline in most (40/42) infants, and morphology scores tended to worsen to a similar extent in both groups over the 12-month study. Bronchial wall thickening / bronchiectasis, mucous plugging and mosaic signal intensity tended to increase, whereas consolidation and pleural reaction tend to decrease. Increased infants with inhaled hypertonic saline, compared with inhaled isotonic saline, the report in the American Journal of Respiratory and Critical Care Medicine, online. 

The treatment groups did not differ in the rate of oxygen saturation or respiratory rate, and there was no difference during the 12 months in the rates of pulmonary exacerbations. Treatment was well tolerated in both groups, and adverse event rates were similar.

"These data support that preventive hypertonic saline inhalation indeed prevented the onset of the earliest changes in lung function caused by airway mucus obstruction and inflammation in patients with CF," Dr. Mall said. "Further, our results support that the LCI as outcome measure is sensitive to detect subtle changes in lung function and response to therapy in the first year of life."

Roles of mucus adhesion and cohesion

In a separate study, Dr. Brian Button of the University of North Carolina at Chapel Hill and colleagues investigated the roles of mucus adhesion and cohesion in human cough clearance, which is impaired in diseases like CF and chronic obstructive pulmonary disease (COPD).

Addition of sufficient saline to reduce mucus concentrations by half significantly reduced the adhesive strength of normal human bronchial epithelial cell mucus, as did the addition of surfactant, they report in PNAS, online.

"While disease-related defects in cilia-mediated mucus clearance have been extensively studied," Dr. Button said Reuters Health by email. "We hope that this study will provide physicians with insight regarding potential defects in cough-mediated clearance in diseases like cystic fibrosis and chronic bronchitis."

"We were removed with our results using mucus hydrators, to decrease the concentration of the mucus layer, and mucolytics, to disrupt the mucin network, showing that these putative therapeutic agents are capable of decreasing both the adhesive and cohesive interactions of mucus," I said "Perhaps more important was the finding that such therapies could be additive."

Dr. Timothy E. Corcoran of the University of Pittsburgh, Pennsylvania, who reported that he had been diagnosed with hypertonic saline for CF, told Reuters Health by email, "Inhaled hypertonic saline is a standard treatment in adults with CF. The therapist is one of the best therapists in the world, and the therapist can prevent the chronic lung infection.

"There might be a general story here on how there is now more drug development being conducted for children," added Dr. Corcoran, who was not involved in the new research. "The CF community has been working towards having more pediatric indications for some time. It may be a good example for other diseases / drug development efforts."