Title : Nasal potential measurements on the nasal floor and under the inferior turbinate : does it matter ?

Francois Vermeulen (1) , Nathalie Feyaerts (1) , Marijke Proesmans (1) , Kris de Boeck (1)

1 Pediatric Pulmonology

Aim : Measurement of nasal potential difference (NPD) is increasingly used as diagnostic test for cystic fibrosis (CF) and for in vivo evaluation of treatments aimed at correcting the defective function of the CFTR-protein. Several methods are used to measure NPD. This study explores the influence of the site of measurement and compares NPD results obtained on the nasal floor and under the inferior turbinate Methods : NPD was measured in 34 CF, 26 heterozygote and 61 control subjects. In every subject measurements were taken simultaneously under the inferior turbinate in one nostril , and on the nasal floor in the other nostril. Criteria for interpretable tracings were predefined. Repeat measurements were done in 57 persons. Results : More interpretable tracings were obtained under the turbinate (120/124) than on the nasal floor (109/124), p=0.015. Within each subject group, mean values obtained were similar for maximal basal potential, response to amiloride and total chloride response. Both techniques discriminate well between CF and controls. Repeatability was similar with both methods: mean differences between 2 measurements approximated zero for most values. Also after correction for different number of interpretable tracings, simulation of sample size calculation for use in CFTR corrective trials was slightly in favour of measurements obtained on the nasal floor. Conclusion : NPD measurements under the inferior turbinate and on the nasal floor have similar discriminative power for diagnostic use. Measurements under the turbinate result in a slightly higher proportion of interpretable tracings but sample size calculation slightly favours the nasal floor method.

Mots clés: Medicine

Francois Vermeulen, Nathalie Feyaerts, Marijke Proesmans, Kris de Boeck. Title : Nasal potential measurements on the nasal floor and under the inferior turbinate : does it matter ?. Pediatric Pulmonology, 2010, 46 (2), pp.145. ⟨10.1002/ppul.21333⟩. ⟨hal-00613785⟩