Evaluation of nasal IgA secretion in normal subjects by nasal spray and aspiration.
OBJECTIVE
Nasal washing (NW) is a popular method for collecting human nasal lavage fluid. However, for NW the subject must be trained, and the method is unsuitable for field studies on untrained subjects. To overcome this problem, we have developed an easy and painless method, a nasal spray and aspiration (NSA) method.


METHODS
This method is different from NW in that the nasal cavity is misted over with saline, and the nasal lavage fluid is aspirated from the nostrils through a silicon tube. First, nasal lavage fluid was obtained twice by NSA with an interval of a week between lavages to evaluate intraindividual variability, and the IgA and protein levels in the nasal lavage fluid were measured by enzyme-linked immunosorbent assay and bicinchoninic acid assay, respectively. Next, the IgA value determined by NSA was compared with that by NW in another 12 normal subjects 2 days after NSA.


RESULTS
In 10 normal subjects, mean volume of saline sprayed into the nose was 0.46+/-0.15 ml (mean+/-S.D.). Mean volume of aspirated nasal lavage fluid containing both sprayed saline and nasal secretion was 0.44+/-0.37 ml. The mean IgA level/mg protein in the nasal lavage fluid determined by NSA was 112+/-18 microg/mg protein at the first and 99+/-20 at the second times of measurement, being highly reproducible. The mean value by NSA was 114+/-19 microg/mg protein, being almost the same as that by NW of 99+/-27.


CONCLUSIONS
These findings suggest that the IgA level/mg protein in nasal lavage fluid determined by NSA instead of NW might be useful for assessing the variability of nasal IgA secretion.
Fujimoto
Chisa
C
Department of Otolaryngology, Institute of Health Biosciences, The University of Tokushima Graduate School, 3-18-15 Kuramoto, Tokushima 770-8503, Japan. chisa0427@hotmail.co.jp
Kido
Hiroshi
H
Sawabuchi
Takako
T
Mizuno
Dai
D
Hayama
Masaki
M
Yanagawa
Hiroaki
H
Takeda
Noriaki
N
D000280:Administration, Inhalation; D000328:Adult; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D055556:Nasal Lavage; D009297:Nasal Mucosa / Q000187:drug effects* / Q000276:immunology*; D011804:Quinolines; D013396:Suction; D055815:Young Adult
D007070:Immunoglobulin A; D007202:Indicators and Reagents; D011804:Quinolines; C047117:bicinchoninic acid