Prolastin aerosol therapy and sputum taurine in cystic fibrosis.

BACKGROUND

Neutrophil elastase in the cystic fibrosis airways inhibits opsonophagocytosis and induces the expression of interleukin-8, a neutrophil chemoattractant. Prolastin is a therapeutic preparation of alpha-1 proteinase inhibitor (alpha1,-PI), a neutrophil elastase inhibitor. The objective of this study was to determine the effects of Prolastin aerosol therapy on airway inflammation in cystic fibrosis.

METHODS

The primary endpoint of this study was sputum taurine, an amino-acid present in high concentrations in neutrophils. Sputum taurine correlates with respiratory exacerbations of cystic fibrosis. Seventeen patients with cystic fibrosis were each assigned to three sequential 10-day periods including first, aerosol therapy of 5 ml saline solution bid; second, aerosol therapy of 250 mg Prolastin bid; third, no aerosol therapy. On days 8, 9 and 10 of each period, early morning sputum was collected for the quantification of alpha1-PI, neutrophil elastase activity, IL-8 and taurine.

RESULTS

During Prolastin therapy, a 3-fold increase in sputum alpha1-PI was observed (P = 0.002). Baseline values of sputum alpha1-PI correlated with the values obtained after Prolastin aerosol (R = 0.77, P < 0.01). Sputum neutrophil elastase activity remained unchanged but taurine decreased after Prolastin therapy (during therapy P = 0.052, after therapy P = 0.026). Prolastin aerosol therapy had no adverse effect on pulmonary function.

CONCLUSIONS

Aerosol therapy with Prolastin in patients with cystic fibrosis leads to a progressive decrease in sputum taurine. This suggests that even in the absence of sustained elastase inhibition, Prolastin aerosol therapy may have a beneficial effect on airway inflammation in patients with cystic fibrosis.