title: Role of TNF-α, sTNF-R55 and sTNF-R75 in inflammation of acute exacerbations of chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Although some recent studies have demonstrated the important role of tumor necrosis factor-α (TNF-α) and soluble TNF receptors (sTNF-R) in inflammation of chronic obstructive pulmonary disease, the exact roles of TNF-α and sTNF-R as well as their interaction remained unclear.
  
  
  OBJECTIVE
  To study changes in levels of systemic and airway local TNF-α and sTNF-R (sTNF-R55, sTNF-R75) in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD), and clarify the relationship between these mediators and airflow limitation in AECOPD patients.
  
  
  METHODS
  TNF-α, sTNF-R55 and sTNF-R75 levels in induced sputum and plasma as well as lung functions were examined in 48 AECOPD patients before and after treatment. Samples from 28 healthy volunteers served as controls.
  
  
  RESULTS
  Compared to healthycontrols, both pre- and posttreatment levels of TNF-α, sTNF-R55 and sTNF-R75 in induced sputum and plasma of COPD patients were higher. In patients with AECOPD, posttreatment TNF-α levels significantly decreased compared to pretreatment levels (0.6 ± 0.46 vs. 0.82 ± 0.35 µg/l in plasma, p < 0.01; 0.48 ± 0.27 vs. 0.82 ± 0.34 µg/l in sputum, p < 0.001). While posttreatment sTNF-R55 and sTNF-R75 levels increased in both kinds of samples, mediator levels in plasma and lung functions were unrelated (p > 0.05). sTNF-R55 and sTNF-R75 levels in induced sputum were positively correlated with lung functions (p < 0.05), while TNF-α levels were negatively correlated with forced expiratory volume in 1 s (FEV1) and the ratio of FEV1 to FEV1 predicted value.
  
  
  CONCLUSIONS
  Inflammatory and anti-inflammatory mediators were imbalanced in the airways of AECOPD patients. It was local inflammation but not systemic inflammation that was closely related to airflow limitation.
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China. zeng_mian@21cn.com
authors.forename: Mian
authors.initials: M
authors.lastname: Zeng
authors.forename: Ying
authors.initials: Y
authors.lastname: Wen
authors.forename: Ling-yun
authors.initials: LY
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Kai-pan
authors.initials: KP
authors.lastname: Guan
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Huang