title: Hypertonic saline solutions do not influence the solubility of sputum from secretor and non-secretor cystic fibrosis patients.
abstract: BACKGROUND
  Functional alterations of the cystic fibrosis transmembrane conductance regulator gene (CFTR) increase the viscoelasticity of pulmonary secretions of cystic fibrosis (CF) patients and require the use of therapeutic aerosols. The biochemical properties of exocrine secretions are influenced by the expression of the FUT2 gene which determine the secretor and non-secretor phenotypes of the ABH glycoconjugates. The aim of this study was to determine the influence of secretor and non-secretor phenotypes by means of photoacoustic analysis, both the typical interaction time (t(0)) and the solubilization interval (Δt) of the sputum of secretor and non-secretor CF patients nebulized by hypertonic saline solutions at different concentrations.
  
  
  METHODS
  Sputum samples were obtained by spontaneous expectoration from 6 secretor and 4 non-secretor patients with CF. Each sample was nebulized with 3%, 6%, and 7% hypertonic saline solutions in a photoacoustic cell. The values of t(0) and Δt were determined using the Origin 7.5(®) computer program (Microcal Software Inc.). The t-test was employed using the GraphPad Instat 3.0(®) computer program to calculate the mean and standard deviation for each parameter.
  
  
  RESULTS
  For all hypertonic saline solutions tested, the mean values of t(0) and Δt do not show statistically significant differences between secretor and non-secretor patients.
  
  
  CONCLUSIONS
  The secretor and non-secretor phenotypes do not influence the in vitro solubilization of the sputum nebulized by hypertonic saline solutions at different concentrations when analysed by photoacoustic technique.
authors.affiliation: Neurological Science Department, Faculdade de Medicina de São José do Rio Preto, FAMERP, São José do Rio Preto, State of São Paulo, Brazil.
authors.forename: Marcelo A I
authors.initials: MA
authors.lastname: Barboza
authors.forename: Cinara C
authors.initials: CC
authors.lastname: Brandão de Mattos
authors.forename: Ana Iara C
authors.initials: AI
authors.lastname: Ferreira
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Barja
authors.forename: Newton
authors.initials: N
authors.lastname: Santos de Faria Junior
authors.forename: Luís Vicente F
authors.initials: LV
authors.lastname: de Oliveira
authors.forename: Luiz C
authors.initials: LC
authors.lastname: de Mattos