Service de Pneumologie, AP-HP, Hôpital Cochin, Paris, France.
J Cyst Fibros. 2011 Jan;10(1):15-20. doi: 10.1016/j.jcf.2010.09.002.
Electrochemical skin conductance measurement is an active electrophysiologic method in which incremental low direct voltage is applied on the skin. It generates a current due to reverse iontophoresis which previous studies suggested to be mostly related to chloride anion movements. As sweat chloride movements upon electric stimulation were likely to be impaired in cystic fibrosis (CF) patients, we designed a proof-of-concept study to measure electrochemical skin conductance in CF patients and control subjects and to test the ability of this method to discriminate CF from controls.
Electrochemical skin conductance was measured in 41 adult patients with classical CF and 20 healthy control subjects. Patients placed their hands and feet on nickel electrodes and an incremental low direct voltage was applied on the anode during 2min. The resulting voltage on the cathode and the current generated between anode and cathode were measured and from them, two electrochemical skin conductance variables were calculated: ESC, obtained when a low voltage of 1.6V was applied, and dESC which took into account electrochemical skin conductances obtained when low and high voltages were applied.
ESC measurements on hands and feet were significantly different in CF patients (on feet: 75±10μSi), as compared with control subjects (62±13μSi, p<0.0001); dESC was also significantly different and more discriminative in CF patients (on feet: 34±24μSi), as compared with control subjects (93±24μSi, p<0.0001). dESC measurement provided a diagnostic specificity of 1 and a sensitivity of 0.93.
These results show that electrochemical skin conductance which is easily and rapidly measured is abnormal in CF patients. Trial registry name in the European Clinical Trials Database (eudraCT): "EZSCAN MUCO1: Mesure de la conductance cutanée par chronoampérométrie", N°EUDRACT: 2007-A00221-52.
电化学皮肤电导测量是一种主动的电生理方法，其中在皮肤上施加递增的低直流电压。它会产生电流，这是由于逆向离子电渗作用，之前的研究表明这主要与氯离子阴离子运动有关。由于囊性纤维化 (CF) 患者的电刺激下的汗液氯离子运动可能受损，我们设计了一项概念验证研究，以测量 CF 患者和对照受试者的电化学皮肤电导，并测试该方法区分 CF 与对照的能力。
对 41 名成年 CF 患者和 20 名健康对照受试者进行了电化学皮肤电导测量。患者将手和脚放在镍电极上，并在阳极上施加 2 分钟的递增低直流电压。测量阴极上的电压和阳极和阴极之间产生的电流，并从这些测量值中计算出两个电化学皮肤电导变量：在施加 1.6V 低电压时获得的 ESC，以及考虑到施加低电压和高电压时获得的电化学皮肤电导率的 dESC。
CF 患者的手部和脚部的 ESC 测量值差异显著（脚部：75±10μSi），与对照组（62±13μSi，p<0.0001）相比；dESC 也在 CF 患者中差异显著，更具区分度（脚部：34±24μSi），与对照组（93±24μSi，p<0.0001）相比。dESC 测量提供了 1 的诊断特异性和 0.93 的敏感性。
这些结果表明，电化学皮肤电导测量值在 CF 患者中异常，该测量值易于快速测量。在欧洲临床试验数据库（EudraCT）中的试验注册名称：“EZSCAN MUCO1：通过 chronoamperometry 测量皮肤电导”，EudraCT 编号：2007-A00221-52。
