Biomarkers of Neutrophilic Inflammation in Exhaled Air of Cystic Fibrosis Children with Bacterial Airway Infections

Abstract

Leukotriene B(4) (LTB(4)) and interleukin-8 (IL-8) are inflammatory mediators involved in the neutrophil response to pulmonary bacterial colonization in cystic fibrosis (CF). The aim of this study was to investigate whether the LTB(4) and IL-8 levels in exhaled breath condensate (EBC) could be related to the type of bacterial colonization in CF patients. The pH level in EBC was analyzed as an estimate of airway acidification. Forty children were evaluated: 10 CF patients with P. aeruginosa, 10 CF patients with S. aureus, 10 not colonized CF patients, and 10 healthy children. LTB(4) and IL-8 in EBC were analyzed by specific enzyme immunoassay kits (EIA). The pH of EBC was measured with a pH-meter after deareation by bubbling with argon. Exhaled LTB(4) was higher in CF children with P. aeruginosa compared to those with S. aureus (P < 0.01), not colonized (P < 0.001), and healthy children (P < 0.01). Exhaled IL-8 was elevated in CF patients colonized by P. aeruginosa compared with other subgroups (vs. not colonized, P < 0.05; vs. healthy children, P < 0.001). IL-8 levels were higher in CF children with S. aureus than in healthy children (P < 0.05). There was an increase in IL-8 levels in not colonized CF patients compared with healthy children (P < 0.05). EBC pH was higher in healthy children compared to CF patients not colonized (P < 0.05). Our data suggest that EBC is suitable for evaluating neutrophil inflammatory mediators (LTB(4), IL-8, and pH) involved in the response to pulmonary bacterial colonization in CF children.

Exhaled breath condensate adenosine tracks lung function changes in cystic fibrosis

“…Many obstacles to assessing airway disease biomarkers can be overcome through use of exhaled breath condensate (EBC) as an airway sample because EBC can be collected simply and noninvasively even in young children (4,39). EBC contains microaerosols of airway secretions diluted in a larger volume of condensed water vapor (22), and many airway inflammatory biomarkers can be measured in EBC and are elevated in EBC from subjects with CF (39).…”

Impact of lung disease on respiratory impedance in young children with cystic fibrosis

“…There are only limited studies investigating associations between inflammatory markers and measurements of lung function in preschool children [14,29]. Associations with lung function measurements and infections have been generally limited to Pseudomonas aeruginosa infections, with studies reporting inconsistent results [11,14,15,17,19,20,29].…”

Exhaled Breath Condensates as a Source for Biomarkers for Characterization of Inflammatory Lung Diseases

“…Leukotriene (LT) B4, formed from hydrolysis of LTA4 has been shown to be a major neutrophil chemoattractant. Elevated LTB4 levels in EBC have been reported in neutrophilic predominant inflammatory lung pathologies including COPD [45] and cystic fibrosis [46]. Its levels have been reported to be significantly elevated in moderate to severely uncontrolled asthma patients whereas in mild episodic asthmatics, its role is not clear [47].…”