Ultrasonic nebulization of hypertonic solution: a new method for obtaining specimens from nasal mucosa for morphologic and biochemical analysis in allergic rhinitis

Various techniques are used to collect specimens from the nasal mucosa for morphologic and biochemical analysis. The purpose of this study was to devise a method that overcomes some of the disadvantages (e.g., invasive procedure, samples not suitable for cytologic and biochemical analysis, lack of standardization, and poor reproducibility) of these techniques. The new method requires subjects, with neck extended, to inhale an ultrasonic nebulization of a hypertonic (3% NaCl) solution (UNHS) for 5 min. They then blow their nose into a Petri dish, one nostril at a time with the other one blocked. The secretions are dispersed with 0.1% dithiothreitol in phosphate buffer solution for 20 min. Total cell count (TCC) is evaluated, and the cellular suspension is divided into two aliquots: one is centrifuged and the supernatants are collected for eosinophil cationic protein (ECP) measurements; the other is cytocentrifuged and the slides, stained with Diff-Quik, are used for differential cell count. The results obtained with the UNHS and nasal lavage (NL) methods were compared. Eleven nonatopic healthy subjects and 19 allergic rhinitic patients were studied. Total cell count (x10(5)) was significantly higher with UNHS than with NL (13.0+/-12.3 vs 1.9+/-1.6; P<0.01) The differential cell count was similar with the two procedures. ECP levels (microg/l) were higher with UNHS than with NL (39.1+/-38.2 vs 16.7+/-41.2; P<0.01). For evaluation of reproducibility, four healthy and six rhinitic subjects underwent UNHS on two occasions within 5 days, and the results of two samples (sample 1 vs sample 2) were analyzed. Reproducibility was good as to TCC, differential cell count, and ECP.