Measurement of Chloride Concentrations of Insensible Sweat Collected From Thumb

This is the authors' abstract. We don't add key points for this paper.

To evaluate the dysfunction of cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel in patients with cystic fibrosis (CF) and chronic pancreatitis, we established a method to measure the sweat Cl− concentrations ([Cl−]) of insensible sweat from the thumb. The sweat rate from one thumb was measured by a perspiration meter and sweat during the period was collected from the other thumb by holding a small sampling tube containing 100 μL water. The Cl− content was measured either by capillary electrophoresis or by a highly sensitive Cl-selective electrode, both of which were sensitive enough to measure 0.06-1.2 mM Cl− in the sample. The sweat [Cl−] in healthy Japanese was 38.0 ± 20.9 mM (mean ± SD, n = 73) and was correlated with the age (p < 0.01). The sweat [Cl−] in a 2-year-old CF patient was 156 mM. Measurement of sweat [Cl−] from the thumb using a Cl-selective electrode is a simple and reliable tool to evaluate the CFTR function.