New Post has been published on Preventive measures in Asthma
New Post has been published on http://the-asthma.com/differential-flow-analysis-of-exhaled-nitric-oxide-in-patients-with-asthma-of-differing-severity-introduction.html
Differential Flow Analysis of Exhaled Nitric Oxide in Patients With Asthma of Differing Severity: Introduction
Asthma is a complex, chronic inflammatory lung disease that is characterized by a specific pattern of airway inflammation airway smooth-muscle hypertrophy and hyperplasia and production of mucus.
The pathophysiology of asthma has traditionally been attributed to an inflammatory process that occurs predominantly in the large airways.
Pathology studies in patients who have died of asthma reveal extensive involvement of the peripheral airways with inflammatory and structural changes, with luminal occlusion with viscid mucus plugs. Transbronchial biopsies have confirmed peripheral airway involvement in severe asthma including the alveoli. On the basis of the physiologic and pathologic evidence, small or peripheral airways and lung parenchyma are clearly implicated in the pathogenesis of asthma, and this aspect seems to be an important feature of patients with asthma and has important implications for drug delivery.
Several tests have been proposed to measure the level of peripheral airway inflammation. Airway inflammation can be measured noninvasively by measuring the sputum eosinophil count and singleflow exhaled nitric oxide (NO) concentration, although these tests are limited to sampling the proximal airways. Two compartment models of pulmonary NO production have been described previously, and studies have shown that alveolar NO (Calv) is elevated in conditions associated with distal lung inflammation such as pulmonary fibrosis and COPD. Calv has been shown to be related to BAL eosinophil cationic protein levels in children and to BAL eosinophil counts in adults. Unlike bronchial NO (Jno), Calv production is not reduced by inhaled corticosteroids (ICS) in patients with asthma, suggesting that it may be derived from a site not accessed by the inhaled drug. In this study, we test whether it is possible to measure Calv concentration in patients with asthma, evaluating the reproducibility/repeatability and the effects of treatment relating to disease severity.