US EPA

2266457 

Journal Article 

Abstract 

Inducible nitric oxide synthase and 3-nitrotyrosine are expressed in alveolar eosinophils in chronic eosinohpilic pneumonia 

Nakaji, H; Matsumoto, H; Niimi, A; Ito, I; Handa, T; Nomura, M; Tabata, H; Iwata, T; Tajiri, T; Inoue, H; Oguma, T; Otsuka, K; Takeda, T; Mochizuki, Y; Mishima, M 

2010 

Yes 

American Journal of Respiratory and Critical Care Medicine
ISSN: 1073-449X
EISSN: 1535-4970 

181 

A2788 

English 

10.1164/ajrccm-conference.2010.181.1_MeetingAbstracts.A2788 

WOS:000208771001701 

is part of a larger document 3452678 Proceedings of the American Thoracic Society 2010 International Conference, May 14-19, 2010, New Orleans

RATIONALE: Inducible nitric oxide synthase (iNOS) that mediates nitric oxide (NO) synthesis in inflamed airways is thought to be expressed in epithelial cells and inflammatory cells such as macrophages. However iNOS expression in eosinophils in respiratory diseases including chronic eosinophilic pneumonia (CEP) has been rarely reported. Since NO promotes eosinophil migration into the airways and initiates nitrative stress, we hypothesized that iNOS and 3-nitrotyrosine (3NT), a metabolite of peroxynitrate, may be consistently expressed in eosinophils in CEP,resulting in eosinophil accumulation by NO leading to self-perpetuating and augment tissue damage in CEP.

METHODS: We examined lung tissues from three patients with CEP. In all cases surgical biopsy was necessary to exclude other possible diagnosis such as cryptogenic organizing pneumonia, and final diagnosis of CEP was established on the basis of eosinophil accumulation in the alveolar lumen and septa. Immunostaining was performed to examine whether eosinophils expressed iNOS and 3NT. In one case exhaled NO levels were measured at multiple flows with a chemiluminescence analyzer and bronchial and alveolar fractions of NO levels were calculated using a two-compartment model (Tsoukias et al, J Appl Physiol 1998).

RESULTS: In all cases, eosinophils in the alveolar lumen and septa clearly expressed iNOS and 3NT. After initiation of oral prednisolone, bronchial and alveolar NO levels determined in one case decreased in parallel with the improvement of symptoms and radiological lung infiltrates.

CONCLUSION: Expression of 3NT, possibly resulting from iNOS expression and NO formation in eosinophils, may play an important role in the pathophysiology of CEP. 

American Thoracic Society 2010 International Conference 

New Orleans, LA 

May 14-19, 2010