Relevance of nasal potential difference in diagnosis of cystic fibrosis among children

Objective. To estimate significance of nasal potential difference (NPD) for the diagnosis of cystic fibrosis (CF) in children with clinical symptoms relevant to the disease, positive sweat test results, and/or supported by genetic analysis. Material and methods. Basal NPD measurement according to E. Alton’s modification was performed in 50 children with CF clinical symptoms supported by positive sweat test results, in 50 children with other obstructive lung diseases, and in 50 healthy children volunteers. A subgroup of 17 children with diagnosis confirmed by detected both mutations in the CF transmembrane regulatory gene was analyzed individually. Results. Basal NPD medium value recorded in 50 children with clinical symptoms of CF, supported by positive sweat test results and/or genetic analysis was -28.0±10.2 mV. Basal NPD medium value in the subgroup of children with detected both CF gene mutations (n=17) was higher than in the subgroup of children with undetected both CF gene mutations (n=33) (-37.1±7.0 mV vs. -23.4±8.3 mV, P<0.001). Basal NPD medium value in patients with other obstructive lung diseases and in healthy children was significantly lower than in the group of children with clinical symptoms of CF, who had positive sweat test results and/or CF gene mutations (consequently -18.1±3.6 mV and -15.5±4.3 mV vs.-28.0±10.2 mV, P