Nasal airway changes assessed by acoustic rhinometry and mediator release during immediate and late reactions to allergen challenge.
BACKGROUND
We have found that acoustic rhinometry is a reliable means of assessing nasal airway caliber changes during the immediate reaction to nasal allergen challenge of sensitive subjects. Comparison of such changes with symptoms and patterns of mediator release could help in the understanding of mechanisms of immediate and late-phase reactions after allergen challenge and their clinical relevance.


METHODS
Nasal minimal cross-sectional area (MCA) was assessed sequentially for 6 hours after two blinded challenges in random order with pollen antigens and buffer diluent in five sensitive human subjects. Comparisons were made with: (1) symptom scores; (2) olfaction changes; and (3) nasal secretion levels of histamine, tryptase, leukotriene C4, serum albumin (a marker of vascular permeability), lactoferrin (a marker of local glandular secretion), and inflammatory cells in nasal scrapings.


RESULTS
In four of five subjects there was a significantly greater decrease in MCA after antigen challenge than after diluent challenge, correlating with the degree of subjective nasal congestion. In two of these four subjects there was a prominent second late-phase decrease in MCA at 3 to 5 hours, whereas the MCA was persistently decreased in an additional subject with accompanying subjective congestion. No significant decrease in olfactory acuity occurred. Levels were significantly higher in nasal secretions obtained after antigen challenge than in those obtained after buffer challenge with histamine (9 +/- 2.7 ng/ml vs 1.2 +/- 0.5 ng/ml; p = 0.04); tryptase (95 +/- 83 ng/ml vs 3 +/- 0.9 ng/ml; p = 0.02), leukotriene C4 (5293 +/- 1385 ng/ml vs 578 +/- 183 ng/ml; p = 0.02), and albumin (123 +/- 9 ng/ml vs 19 +/- 1.6 ng/ml; p = 0.005) but not with lactoferrin (4.6 +/- 1.2 ng/ml vs 4.1 +/- 28 ng/ml; p = not significant). Granulocyte exudation was seen after antigen challenge but not after buffer diluent challenge. However, there was not a precise correlation between decreases in MCA with changes in levels of these mediators in individual subjects.


CONCLUSIONS
Acoustic rhinometry can quantitatively assess congestion during immediate and late-phase reactions after nasal challenge without significant correlation to the degree of individual inflammatory events assessed.
Zweiman
B
B
Department of Medicine, University of Pennsylvania Medical Center, Philadelphia 19104-6057, USA.
Getsy
J
J
Kalenian
M
M
Lane
A
A
Schwartz
L B
LB
Doty
R
R
Lanza
D
D
D000162:Acoustics; D000328:Adult; D000418:Albumins / Q000378:metabolism; D002559:Cerebrospinal Fluid Rhinorrhea / Q000503:physiopathology; D053818:Chymases; D004804:Eosinophils / Q000166:cytology; D006098:Granulocytes / Q000166:cytology; D006636:Histamine Release; D006801:Humans; D007781:Lactoferrin / Q000378:metabolism; D017997:Leukotriene C4 / Q000378:metabolism; D009296:Nasal Cavity / Q000033:anatomy & histology*; D009297:Nasal Mucosa / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D015508:Nasal Obstruction / Q000175:diagnosis*; D009299:Nasal Provocation Tests; D012697:Serine Endopeptidases / Q000378:metabolism; D013997:Time Factors; D053802:Tryptases
D000418:Albumins; D017997:Leukotriene C4; D007781:Lactoferrin; D012697:Serine Endopeptidases; C083294:chymase 2; D053818:Chymases; D053802:Tryptases