Timing of dornase alfa inhalation for cystic fibrosis

Dornase alfa in Cystic Fibrosis: indications, comparative studies and effects on lung clearance index

Cystic fibrosis (CF) is the most common inherited disease in Caucasian populations, affecting around 50,000 patients in Europe and 30,000 in United States. A mutation in CF trans-membrane conductance regulator (CFTR) gene changes a protein (a regulated chloride channel), which is expressed in many tissues. Defective CFTR results in reduced chloride secretion and an overage absorption of sodium across the epithelia, leading to thickened secretions in organs such as pancreas and lung. Gradually, there have been considerable improvements in the survival of people with CF, thanks to substantial changes in specialized CF care and the discovery of new CFTR modulators drugs. Nevertheless, lung disease remains the most common cause of death. For these reasons improvement of sputum clearance is a major therapeutic aim in CF. So far, symptomatic mucolytic therapy is mainly based on inhalation of dornase alfa, hypertonic saline or mannitol, in combination with physiotherapy. The major component of mucus in CF is pus including viscous material such as polymerized DNA derived from degraded neutrophils. Dornase alfa cleaves the DNA released from the neutrophils and reduces mucous viscosity, and further prevent airway infections and damage to the lung parenchyma. In this review we will summarize the current knowledge on dornase alfa in the treatment of CF lung disease, especially highlighting the positive effect on lung clearance index, a sensitive measure of ventilation inhomogeneity.

Hypertonic saline in people with cystic fibrosis: review of comparative studies and clinical practice

Cystic fibrosis (CF) is a multisystem disorder, caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. These cause a reduced secretion of chloride, a marked absorption of sodium and, therefore, of water, through the epithelium, resulting in the formation of thickened secretions in organs such as lung or pancreas. These viscous secretions lead to airway obstruction, chronic infection and inflammation resulting in progressive lung damage, bronchiectasis and eventual respiratory failure. Although the average life expectancy has increased over the last 30 years, lung disease is the most common cause of death in people with CF. For these reasons, the improvement of sputum clearance is a major therapeutic aim in CF and early initiation of airway clearance is widely recommended and implemented. Symptomatic mucolytic therapy today is mainly based on inhalation of DNase, hypertonic saline or mannitol, in combination with physiotherapy. Mucolytic agents break down the gel structure of mucus and therefore decrease its elasticity and viscosity, reducing the pulmonary exacerbation frequency and to improve and stabilize lung function. Nevertheless, high quality studies comparing these mucolytic drugs are still few, and the individual experiences of patients and caregivers explain the high variability of their use globally. This review will summarize the current knowledge on hypertonic saline in the treatment of CF lung disease. Furthermore, we report the real-world prescription of inhaled mucolytic agents in CF.