[Correlation of results of immunocytochemical, electrophysiologic, and molecular studies in patients with cystic fibrosis].

In 13 cystic fibrosis (CF) patients of 5 to 23 years of age with a known mutation spectrum of gene CFTR, sweat chloride values and nasal-potential differences (NPD) were measured and localization characteristics of the protein product of gene CFTR in the cells of nasal epithelium were studied. Sweat Chloride values were normal or boundary (24 to 62 mM/l) in six CF patients. In seven CF patients, these values were significantly above the estimates 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. Histochemical studies clearly revealed the localization of the CFTR protein on the apical membrane of the nasal epithelium. Depending on the type of mutation, the protein product of gene CFTR was either absent or regularly distributed in the cytoplasm 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, highly informative methods of CF diagnostics.