Correlation of results obtained from immunocytochemical, electrophysiological, and molecular studies in patients with cystic fibrosis

In 13 cystic fibrosis (CF) patients from 5 to 23 years of age with a known mutation spectrum of gene CFTR, sweat chloride values and nasal-potential d ifferences (NPD) were measured and localization characteristics of the prot ein product of gene CFTR in the cells of nasal epithelium were studied. Swe at Chloride values were normal or boundary (24 to 62 mM/l) in six CF patien ts. In seven CF patients, these values were significantly above the estimat es for the control group. On average, the NPD values were -44.7 +/- 2.2 mV (from -32.5 to -68.9 mV) and -17.2 +/- 1.8 mV (from -6.8 to -30.2 mV) in CF patients and the control group, respectively. Immunohistochemical studies clearly revealed the localization of the CFTR protein on the apical membran e of the nasal epithelium. Depending on the type of mutation, the protein p roduct of gene CFTR was either absent or regularly distributed in the cytop lasm in CF patients; it was not detected in the apical membrane. Thus, NPD measurements and the analysis of the localization of the protein product of gene CFTR in scrapes of nasal epithelium were shown to be additional, high ly informative methods of CF diagnostics.