A new inflammation marker of chronic obstructive pulmonary disease——adiponectin

Objective To determine the level of adiponectin (APN) in serum and induced sputum of patients with chronic obstructive pulmonary disease both during acute exacerbation (AECOPD) and silent stage, and investigate APN' s role as a marker of inflammation in the pathogenesis of COPD. Method From October 2008 to October 2009,30 male AECOPD patients in the emergency department, 30 male silent COPD patients in the department of respiratory diseases and 30 healthy nonsmoking male volunteers were included. All subjects' serum and induced sputum were collected, and they were all of normal weight(BMI range of 18.5～ 24.9 kg/m2). Patients were excluded if they suffered from severe bronchial asthma, bronchiectasis or autoimmune disease. The number of cells in induced sputum was counted and the cell type was classified. The concentrations of APN, IL-8, IL-6 and TNF-α in both serum and sputum were measured by using ELISA, and their pulmonary function was tested. The different groups were compared among them by using the t -tests, ANOVA analysis or nonparametric analysis, the relation between variables was assessed by using the Pearson or Spearman correlation test. Results The concentrations of APN in both serum and induced sputum of AECOPD patients were significantly higher than those in the silent COPD patients and the control subjects ( P ＜ 0.01 ). The concentrations of APN in the silent COPD patients were significantly higher than those in the control subjects ( P ＜ 0. 01 ). There were significant relationships between the concentrations of APN in serum and induced sputum and the levels of IL-8 and TNF-α in AECOPD patients ( r = 0.739, 0. 734,0.852 and 0. 857, respectively, P ＜ 0. 05) and in silent COPD patients ( r = 0.751,0.659, 0.707 and 0.867, respectively, P ＜0.05). There was significant relation betweenship between APN and neutrophil in induced sputum of AECOPD patients (r = 0.439, P ＜ 0.05). Conclusions APN was involved in the process of systemic and airway inflammation of COPD, and it was related with IL-8 and TNF-α. APN can be used as a new inflammation marker for COPD. Key words: Chronic obstructive pulmonary disease(COPD);  Serum;  Induced sputum;  Adiponectin(APN); Neutrophil;  Interleukin-8(IL-8) ; Tumor necrosis factor-α(TNF-α);  Interleukin-6 (IL-6)