Basic report
Influence of secretor and non-secretor phenotypes on the solubilization of pulmonary mucus by three common medicines in cystic fibrosis patients assessed using photoacoustic analysis

Introduction: Cystic fibrosis is caused by a mutation of the gene CFTR producing increased viscoelasticity of pulmonary secretions. Affected patients are required to use therapeutic aerosols. The enzyme a-2-L-fucosiltransferase (FUTII) coded by FUT2 gene controls the expression of ABH glycoconjugates in the exocrine secretions as allowing the classification of individuals into secretor and non secretor phenotypes. The aim of our study was to determine the influence of secretor and non secretor phenotypes by means of photoacoustic analysis, analysing both the typical interaction time (t0) and the solubilization interval (Dt) of the sputum of secretor and non secretor cystic fibrosis patients nebulized with therapeutic aerosols.

Material and methods: Sputum samples were obtained by spontaneous expectoration from 6 positive and 4 negative secretor cystic fibrosis patients. Each sample was nebulized with the following drugs: tobramycin, alpha dornase, and N-acetylcysteine in a photoacoustic cell with t0 and Dt being determined using the Origin 7.5® computer program (Microcal Software Inc.). The t-test was employed using the GraphPad Instat computer program to calculate the mean and standard deviation for each parameter.

Results: The mean values of t0 or Dt were statistically significant between the groups for tobramycin (t0: P=0.03; Dt: P=0.88) and dornase alpha (t0: P=0.35; Dt: P=0.04) but not for N-acetylcysteine (t0: P=0.35; Dt: P=0.99).

Conclusions: The results show that the secretor and non secretor phenotypes influence the in vitro solubilization of pulmonary mucus of cystic fibrosis patients nebulized with tobramycin and alpha dornase, but not with N-acetylcysteine.