Managing asthmatic airway inflammation: What is the role of expired nitric oxide measurement?
✍ Scribed by Benjamin Gaston
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 968 KB
- Volume
- 28
- Category
- Article
- ISSN
- 1538-5442
No coin nor oath required. For personal study only.
✦ Synopsis
U
he use of available preventive strategies can make hospital admission rare for patients established to have asthma. These strategies have been augmented by the application of recent advances--such as expired nitric oxide (NO) measurement--that are likely to decrease further the morbidity of both asthma and asthma therapy. The following outline reviews both current recommendations for pediatric asthma management and the role of expired NO measurement as a guide to the use of antiinflammatory therapy. Clinical implications are summarized.
Asthma is an Inflammatory Disease
Fundamentally, asthma is not caused by smooth muscle contraction but rather by airway inflammation. 1-3 Lung specimens from patients who have died of asthma-and sputum and airway biopsies from living patients-consistently show the presence of eosinophils. 2,4 Mast cells, epithelial cells, and lymphocytes, particularly Thelper type 2 (Th2) cells, 3,5 are activated, and chemokines and cytokines such as interleukin 4 and interleukin 5 are produced. These molecules in turn promote immunoglobulin E production and recruit and further activate cells capable of excreting cytotoxic, bronchoconstricting, and fibrosing products. 6-u In this regard, increased airway, blood, or urine levels have been measured in subjects with asthma of histamine, eosinophilic cationic protein, leukotrienes, platelet activating factor, neurokinins, transforming growth factor 13, and a variety of other secretory/degranulation products. These cause the airway swelling, mucous hypersecretion, and airway smooth muscle narrowing that give rise to asthmatic expiratory airflow limitation and dyspnea.6-sj2-15