Apoptosis of T Lymphocytes Isolated from Peripheral Blood of Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

PURPOSE: Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways and progressive destruction of lung parenchyma. Apoptosis is critical for the maintenance of normal tissue homeostasis and is in equilibrium with proliferation and differentiation. This study was undertaken to investigate relationship between apoptosis of peripheral blood lymphocytes during exacerbation of COPD and inflammatory response that characterizes this condition. MATERIALS AND METHODS: Seventeen patients with COPD exacerbation, 21 stable COPD, and 12 control subjects were included. T lymphocytes were isolated from peripheral blood using MACS. Apoptosis of T lymphocytes was assessed with FACS using annexin V and 7-aminoactinomycin. Serum levels of interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-α were determined by an immunoassay technique. RESULTS: There was significantly increased percentage of apoptotic lymphocytes, CD 4(+), and CD 8(+) T cells in the peripheral blood of patients with exacerbation of COPD compared with stable COPD. Serum levels of IL-6, IL-8, and TNF-α were significantly increased in patients with exacerbation of COPD compared with stable COPD. Only TNF-α presented a positive correlation with apoptotic lymphocytes in patients with exacerbation of COPD. CONCLUSION: Increased apoptotic lymphocytes may be associated with upregulation of TNF-α in the peripheral blood of patients with acute exacerbation of COPD.