Exhaled and Sputum Nitric Oxide in Bronchiectasis: Correlation With Clinical Parameters

Abstract

Although there has been tremendous attention on endogenous nitric oxide (NO) production in many respiratory and systemic diseases, little is known on NO production in bronchiectasis. We determined exhaled and sputum NO levels in 109 patients with stable bronchiectasis (71 women; mean +/- SD age, 58.2 +/- 14.1 years) and 78 control subjects (39 women; mean age, 56.7 +/- 12.1 years) by using an automatic chemiluminescence analyzer. There was no significant difference in exhaled NO between patients with bronchiectasis and control subjects (p = 0.11). Bronchiectasis patients with Pseudomonas aeruginosa infection had a significantly lower exhaled, but not sputum, NO levels than their counterparts and control subjects (p = 0.04 and p = 0.009, respectively). Exhaled NO correlated with 24-h sputum volume in P aeruginosa-infected patients (r = - 0.36; p = 0.002). After adjustment for sputum volume and number of bronchiectatic lung lobes, P aeruginosa-infected patients still had lower exhaled NO levels than their counterparts (p = 0.01). There was no correlation between exhaled NO with FEV(1), FVC, and the number of bronchiectatic lung lobes (p > 0.05). Sputum NO levels were not different between patients and control subjects (p = 0.64), and had no correlation with clinical parameters. Exhaled NO appears to be reduced among bronchiectasis patients with P aeruginosa infection independent of other clinical parameters, and further studies on the potential mechanisms and pathogenetic implications of this reduction should be pursued.