Relation of sputum inflammatory markers to symptoms and lung function changes in COPD exacerbations

Abstract

Background-Although it is presumed that exacerbations of chronic obstructive pulmonary disease (COPD) are associated with increased airway inflammation, there is little information available on inflammatory markers during an exacerbation and the relationship with severity or time course of recovery. A study was undertaken to investigate the sputum cell and cytokine characteristics of COPD when stable and during an exacerbation. Methods-Induced sputum samples from 57 patients with moderate to severe COPD were analysed (44 samples were taken during a stable period and 37 during an exacerbation). The patients recorded daily symptoms on diary cards. Cell counts and sputum levels of interleukin (IL)-6 and IL-8 were measured. Results-Patients with >3 exacerbations/ year had higher median stable sputum levels of IL-6 (110 (95% CI 11 to 215) pg/ ml) and IL-8 (6694 (95% CI 3120 to 11995) pg/ml) than those with <2 exacerbations/year (22 (95% CI 12 to 93) and 1628 (95% CI 607 to 4812) pg/ml, respectively). Median IL-6 levels were increased during exacerbations compared with stable conditions. The levels of IL-6 during exacerbations were related to the presence of a cold and to the total cell count and eosinophil and lymphocyte numbers, while IL-8 was positively correlated with all sputum cell counts. Sputum cell counts and cytokine levels during an exacerbation did not predict the size and duration of lung function changes in the exacerbation. Conclusions-Patients with more frequent exacerbations have higher baseline sputum cytokine levels, which may predict the frequency of future exacerbations. (Thorax 2000;55:114-120)

Detection of rhinovirus in induced sputum at exacerbation of chronic obstructive pulmonary disease

“…Changes in lower airway inflammatory indices have been associated with experimental rhinovirus infection [7,28]. It has previously been shown that there are increased inflammatory changes in the lower airway during COPD exacerbation [4]. As in the previous study, it was found that induced sputum IL-6 levels increased significantly at exacerbation compared to baseline, although there were no corresponding changes in IL-8 concentration or cell counts [4].…”

“…Induced sputum at exacerbation and baseline was obtained using standard methods validated in the authors' laboratory [4,13]. Briefly, after premedication with 200 mg inhaled salbutamol via a metered-dose inhaler with spacer, nebulization with 3% saline was commenced using the DeVilbiss UltraNeb 2000 ultrasonic nebulizer (DeVilbiss Healthcare, Heston, UK).…”

“…Induced sputum samples were examined as soon as possible within 2 h after sampling, adopting methods previously evaluated [4,13]. The selected portion of sputum was placed in a preweighed tube and the weight of the selected portion of sputum recorded.…”

“…COPD exacerbations have major effects on health status [3], are associated with considerable morbidity and mortality, and are frequently triggered by upper respiratory tract infections [4]. These exacerbations are associated with increased airway inflammation and airflow obstruction [4,5].…”

“…COPD exacerbations have major effects on health status [3], are associated with considerable morbidity and mortality, and are frequently triggered by upper respiratory tract infections [4]. These exacerbations are associated with increased airway inflammation and airflow obstruction [4,5]. Studies in childhood asthma have shown that viruses, especially rhinovirus (the cause of the common cold), can be detected by polymerase chain reaction (PCR) in nasopharyngeal samples from a large proportion of these exacerbations [6].…”