Correlation Between Tumor Necrosis Factor-α and Interleukin-1β in Exhaled Breath Condensate and Pulmonary Function.

BACKGROUND

Exhaled breath condensate (EBC) has emerged as a noninvasive method for assessing inflammation in lung diseases. Our aim is to investigate the correlation between tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) in EBC and in lung tissue, and between these values in EBC with pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

To ensure the availability of lung tissue, 60 patients undergoing resection for early lung cancer were divided into 3 groups: a COPD treatment group, a COPD control group and a non-COPD group. Patients in the COPD treatment group received what was termed "lung-protective treatment" including ambroxol, budesonide and ipratropium bromide in addition to chest physiotherapy. Patients underwent pulmonary function testing and EBC collection, and TNF-α and IL-1β were detected by enzyme-linked immunosorbent assay (ELISA). TNF-α and IL-1β in lung tissues were evaluated by immunoflorescense. Correlations were analyzed by Pearson correlation coefficients.

RESULTS

The TNF-α and IL-1β levels in EBC were significantly higher in the COPD groups compared with the non-COPD group before surgery (all P < 0.01), and the levels were significantly decreased after lung-protective treatment was received before surgery (all P < 0.01). TNF-α and IL-1β levels in EBC were significantly decreased in all patients after surgery with lung-protective treatment (P = 0.027, P = 0.004). TNF-α and IL-1β content in lung tissues was significantly higher in the COPD groups (all P < 0.05), and the histologic analysis showed similar results. Negative correlations between FEV1/FVC and expression of TNF-α and IL-1β were observed. There was a positive correlation between TNF-α and IL-1β in lung tissues and in EBC.

CONCLUSIONS

TNF-α and IL-1β in EBC are potential biomarkers for evaluating pulmonary function and inflammation in patients with COPD. Furthermore, lung-protective treatment is effective in reducing inflammation in patients with COPD.