O. Duperrex et al., A NEW DEVICE FOR IN-VIVO MEASUREMENT OF NASAL TRANSEPITHELIAL POTENTIAL DIFFERENCE IN CYSTIC-FIBROSIS PATIENTS AND NORMAL SUBJECTS, The European respiratory journal, 10(7), 1997, pp. 1631-1636
Measurement of transepithelial potential difference (PD) on the nasal
mucosa bar, been proposed to test for defective ion transport in cysti
c fibrosis (CF), and its possible correction after gene therapy or oth
er treatments, The ''classical'' method records nasal PD under the inf
erior turbinate, with the disadvantage that the tip of the electrode i
s not seen by the operator, We have developed a purpose-designed perfu
sion electrode for PD recording on the visible, medial/posterior aspec
t of the turbinate, We wanted to determine whether such PD recordings
adequately discriminate between CP patients and normal subjects,Measur
ements of baseline PD and response to a standardized perfusion protoco
l were performed in 20 normal subjects and 12 CP patients, Solutions o
f amiloride, with or without low chloride buffer were applied for 3 mi
n. Increased baseline PD and depolarization after amiloride discrimina
ted CF patients from normal subjects. Only one CF patient overlapped w
ith the normal range, Superfusion of low chloride buffer with amilorid
e and terbutaline caused repolarization in 18 out of 20 normal subject
s (90%), consistent with physiological Cl- secretion process, but in n
one of the CP patients. We conclude that measurements of potential dif
ference on the medial/posterior aspect of the turbinate can discrimina
te between cystic fibrosis patients and normal subjects, At this site,
visual control of the measurement is possible, and the mucosa is easi
ly accessible for subsequent cytological sampling or biopsy.