Intestinal current measurement and nasal potential difference to make a diagnosis of cases with inconclusive genetics and sweat test.

Background: Nasal potential difference (NPD) and intestinal current measurements (ICM) are cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers recommended to make a diagnosis in individuals with inconclusive sweat test and genetics and a clinical suspicion for cystic fibrosis (CF) or CFTR-related disorder (CFTR-RD).

Methods: NPD and ICM were measured according to standard operating procedures of the European Cystic Fibrosis Society Diagnostic Network Working Group.

Results: We assessed 219 individuals by NPD or ICM who had been referred to our laboratory due to clinical symptoms suggestive of CF, but inconclusive sweat test and genetics (median age: 16.