IL-6 and IL-13 in Induced Sputum of COPD and Asthma Patients: Correlation with Respiratory Tests

Abstract

Background: IL-6 is strongly implicated in the development of chronic obstructive pulmonary disease (COPD). IL-13 is the well-documented central mediator in allergic asthma. IL-6 is attributed to the proinflammatory activities in COPD as well as asthma. In COPD patients exacerbation is increased by serum IL-6. The association of IL-13 as well as IL-6 with the impaired respiratory function of asthma patients remains controversial. Objectives: The aim of this study was to compare the concentration of IL-6 and IL-13 in the induced sputum of asthma and COPD patients, and to assess the possible association of these cytokines with the impairment of lung function. Methods: Twenty-six subjects with COPD and 18 subjects with asthma were enrolled in this study. IL-6 and IL-13 levels were measured in induced sputum by ELISA and correlated with the results of respiratory tests. Results: The induced sputum of COPD patients had a significantly higher IL-6 level than the sputum of asthma subjects while no significant differences were found in the levels of IL-13. There was a statistically significant negative correlation between IL-6 level and FEV₁ or FEV₁/FVC in asthma patients (r = –0.59 and –0.54, respectively) and a negative correlation that did not reach statistical significance between IL-6 level and FEV₁, FEV₁% or FVC in COPD subjects (r = –0.30, –0.30 and –0.38, respectively). There was no relationship between concentrations of IL-13 and impaired respiratory function. Conclusions: Our results confirmed that IL-6, but not of IL-13, is associated with respiratory disorders in both asthma and COPD patients.

A comparative study of sTREM-1, IL-6 and IL-13 concentration in bronchoalveolar lavage fluid in asthma and COPD: A preliminary study

“…Therefore, it was assumed that the IL-6/IL-13 ratio characterizes asthma and COPD more accurately than the levels of either single cytokine, since the level of an individual cytokine may change dynamically in the course of the disease. 19 The results obtained supported this hypothesis. The IL-6/IL-13 ratio in BALF was significantly different in asthma than in COPD, even though there was no difference between BALF sTREM-1 levels in these 2 diseases.…”

“…It has previously been shown that the ratio of IL-6 and IL-13 concentration in induced sputum is significantly different in asthmatics than in COPD patients. 19 To date, the concentration of sTREM-1 in asthma and COPD patients has been evaluated in serum and plasma only. Systemic sTREM-1 levels correlated positively with asthma and COPD severity and negatively with lung function, and are a good marker of neutrophilic inflammation.…”

Hydrogen-rich saline inhibits tobacco smoke-induced chronic obstructive pulmonary disease by alleviating airway inflammation and mucus hypersecretion in rats

“…24 The increased serum IL-6 level has been improved in patients with COPD 25 and IL-6 level in the induced sputum of COPD patients is significantly promoted as well compared with that of asthma patients. 26 TNF-a, one of early regulators in immune response, is responsible for stimulating the release of secondary pro-inflammatory cytokines. 27 IL-10 is an anti-inflammatory cytokine.…”

IL-6 Receptor α Defines Effector Memory CD8+T Cells Producing Th2 Cytokines and Expanding in Asthma

“…The association of IL-6 and IL-6 receptor a (IL6Ra, CD126) with asthma was reported, suggesting a potential involvement of these molecules in the development of asthma (8)(9)(10)(11)(12). IL-6 can affect T-cell functions including cytokine production, cell proliferation, and survival (8,(13)(14)(15)(16).…”