Nasal mucosal expression of nitric oxide synthases in patients with allergic rhinitis and its relation to asthma.
BACKGROUND
Nitric oxide (NO) has contradictory roles in the pathophysiology of allergic inflammation in both allergic rhinitis (AR) and asthma. Small amounts of NO produced by constitutive NO synthase (NOS) is anti-inflammatory, whereas large amounts produced by inducible NOS (iNOS) are proinflammatory.


OBJECTIVE
To investigate the difference in constitutive endothelial NOS (eNOS) and iNOS expression in nonallergic and allergic mucosa and the possible relation of this to the coexistence of asthma in seasonal AR.


METHODS
Seventeen patients (10 women and 7 men) with seasonal AR and 9 nonallergic patients (5 women and 4 men) with nasal septum deviation were enrolled. Inferior turbinate nasal biopsy specimens were obtained in all. Levels of eNOS and iNOS expressed as immunohistochemical scores (HSCOREs) were determined immunohistochemically from the specimens.


RESULTS
The mean +/- SD HSCOREs for eNOS in patients with seasonal AR were not significantly different from those of the nonallergic controls (1.85 +/- 0.78 vs 1.63 +/- 0.54; P = .12). On the other hand, the mean +/- SD HSCOREs for iNOS were significantly higher in patients with seasonal AR (1.75 +/- 0.75 vs 0.71 +/- 0.6; P = .004). Furthermore, although eNOS expression was not different between seasonal AR patients with and without asthma, the mean +/- SD HSCOREs for iNOS were significantly higher in the patients with asthma (1.93 +/- 0.78 vs 1.65 +/- 0.55; P = .01).


CONCLUSIONS
Increased expression of iNOS might have a role in the development of allergic inflammation in upper and lower airways and in comorbidity of AR and asthma.
Yuksel
Hasan
H
Department of Pediatric Allergy and Pulmonology, Celal Bayar University, Manisa, Turkey. hyukselefe@hotmail.com
Kirmaz
Cengiz
C
Yilmaz
Ozge
O
Pinar
Ercan
E
Vatansever
Seda
S
Degirmenci
Papatya Bayrak
PB
Ozbilgin
Kemal
K
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000201:enzymology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009297:Nasal Mucosa / Q000201:enzymology* / Q000473:pathology; D009300:Nasal Septum / Q000201:enzymology / Q000473:pathology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D006255:Rhinitis, Allergic, Seasonal / Q000201:enzymology*
D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III