Acute respiratory distress syndrome (ARDS) is associated with diffuse
inflammation, alveolar epithelial damage, and leakage of
plasma proteins into the alveolar space, which together contribute to inactivation of
pulmonary surfactant and
respiratory failure. Exogenous
surfactant delivery is therefore considered to hold potential for ARDS treatment, but clinical trials with natural derived
surfactant or synthetic
surfactant containing a
surfactant protein C (SP-C) analogue have been negative. Synthetic
surfactant CHF5633, containing analogues of SP-B and SP-C, may be effective against ARDS. The aim here was to compare treatment effects of
CHF5633 and animal-derived
surfactant poractant alfa in animal model of ARDS. ARDS was induced in adult New Zealand rabbits by mild lung lavages followed by injurious ventilation until
respiratory failure (P/F ratio <26.7 kPa). The animals were then treated with intratracheal bolus of 200 mg/kg
CHF5633 or
poractant alfa (Curosurf® ), or air as control. The animals were subsequently ventilated for an additional 4 hr and respiratory parameters were recorded regularly. Postmortem, histological analysis, degree of lung
edema, and levels of the
cytokines TNFα,
IL-6, and
IL-8 in lung homogenates were evaluated. Both
surfactant preparations improved lung function, reduced the levels of pro-inflammatory
cytokines, and degree of lung
edema to very similar degrees versus the controls. No significant differences in any of the analyzed parameters were observed between the CHF5633- and
poractant alfa-treated groups. This study indicates that single dose of
CHF5633 improves lung function and attenuates
inflammation as effectively as
poractant alfa in experimental ARDS caused by injurious ventilation.