Abnormal electrochemical skin conductance in cystic fibrosis Dominique Hubert, Philippe Brunswick, Jean-Henri Calvet, Daniel Dusser, Isabelle Fajac  Journal of Cystic Fibrosis  Volume 10, Issue 1, Pages 15-20 (January 2011) DOI: 10.1016/j.jcf.2010.09.002 Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions

Fig. 1 General presentation of the device measuring electrochemical skin conductance. Hand and feet nickel electrodes and electronic board allowing voltage application, current and voltage measurements, recordings and data management. Journal of Cystic Fibrosis 2011 10, 15-20DOI: (10.1016/j.jcf.2010.09.002) Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions

Fig. 2 Individual current density–voltage curves for a control subject (Ct, black squares) and a patient with cystic fibrosis (CF, black circles). Electrochemical skin conductance is the slope of the curve, i.e. the ratio between the current measured (Y-axis) and the difference in voltages obtained (∆anode−cathode: X-axis). ESC is the electrochemical skin conductance when a voltage of 1.6V was applied on the anode (i.e. the slope of the curve obtained at the 4th step of increasing voltage, corresponding to the 4th point of each curve). dESC is the difference between the electrochemical skin conductance obtained at 3.6V (i.e. the slope obtained when a voltage of 3.6V was applied on the anode, which was the 14th step of increasing voltage corresponding to the 14th point of each curve) and ESC (obtained at 1.6V). dESC is shown on the figure by the up down arrow. Journal of Cystic Fibrosis 2011 10, 15-20DOI: (10.1016/j.jcf.2010.09.002) Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions

Fig. 3 Electrochemical skin conductance measurements (ESC) when a voltage of 1.6V is applied on the anode for hands (A) and feet (B) in control subjects and patients with cystic fibrosis (CF). (The line for each group is the mean value; **: p<0.01; ****: p<0.0001). Journal of Cystic Fibrosis 2011 10, 15-20DOI: (10.1016/j.jcf.2010.09.002) Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions

Fig. 4 dESC on hands (A) and feet (B) in control subjects and patients with cystic fibrosis (CF). dESC is the difference between the electrochemical skin conductance obtained at 3.6V (i.e. the ratio between the current measured and (∆anode−cathode) obtained when a voltage of 3.6V was applied on the anode) and ESC (obtained at 1.6V). (The dotted line represents the cut-off of 60μSi; the line for each group is the mean value; ****: p<0.0001). Journal of Cystic Fibrosis 2011 10, 15-20DOI: (10.1016/j.jcf.2010.09.002) Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions

Fig. 5 Relation between sweat chloride concentrations and dESC for hands (A) and feet (B) in control subjects (squares) and patients with cystic fibrosis (diamonds). Journal of Cystic Fibrosis 2011 10, 15-20DOI: (10.1016/j.jcf.2010.09.002) Copyright © 2010 European Cystic Fibrosis Society. Terms and Conditions