The Clinical Significance of Exhaled Nitric Oxide in Asthma

Abstract

Asthma is an inflammatory disease of the airways, for which many therapeutic options are available. Guidelines for the management of asthma suggest a stepwise approach to pharmacotherapy based on assessment of asthma severity and control. However, the assessment of asthma control presently relies on surrogate measures, such as the frequency of symptoms or the frequency of use of short-acting beta2-adrenergic agonists. There is no simple, noninvasive technique for the assessment of severity of actual airway inflammation in asthma. The collection and analysis of nitric oxide (NO) levels in exhaled breath has recently become feasible in humans. Based on increased exhaled NO (eNO) levels in patients with asthma, eNO analysis has been proposed as a novel, noninvasive approach to the assessment and monitoring of airway inflammation, and as a basis for adjustments in asthma therapy. In the present paper, the relationship of elevated eNO levels in asthma with inflammatory, physiological and clinical markers of asthma in adults was reviewed. Use of eNO is a promising tool for diagnosing asthma, for monitoring asthma control and for guiding optimal anti-inflammatory asthma therapy. However, because of many unresolved questions, eNO cannot be recommended at present for routine clinical management of adults with asthma.

Single-dose desloratadine and montelukast and allergen-induced late airway responses

“…Relative to bronchial biopsy and bronchial lavage, eNO measurement is an attractive noninvasive procedure for assessing airway inflammation and therapeutic efficacy when incorporated into the allergen challenge model. However, the reported lack of specificity and selectivity may limit the validity and interpretation of the data [26]. It must also be acknowledged that the present study may not be appropriately powered to detect a significant change in eNO concentration.…”

Metabolomic profiling of asthma and chronic obstructive pulmonary disease: A pilot study differentiating diseases

“…This has not been demonstrated for previous single biomarkers (eg, exhaled nitric oxide [NO], urine leukotrienes, and eosinophil cationic protein). [12][13][14] Airway dysfunction, increased work of breathing, and hypoxemia will cause cellular stress inside and outside the lung. As such, we were not deterred from using urine as our biofluid of interest compared with using more invasive samples from the airway.…”

Therapeutic efficacy of chitosan against invasive candidiasis in mice

“…NO strongly promotes chemotaxis of inflammatory cells in the lung. In asthmatics, NO production is greatly enhanced due to the induction of iNOS by pro-inflammatory cytokines leading to elevated levels of exhaled NO (Pendharkar and Mehta, 2008). In Candidiasis, the production of NO is greatly increased due to the induction of iNOS by pro-inflammatory cytokines leading to elevated levels of exhaled NO (Karaman et al, 2011).…”