[Role of mediators in the onset of COPD]

Chronic obstructive pulmonary disease (COPD) is a chronic airway disorder characterized by obstructive airflow limitation which is not completely reversible with treatment. Inflammatory changes in the peripheral airways, especially those with the diameter less than 2 mm(so called small airway disease) have been speculated to be initial steps of COPD. However, it remains unclear which cytokines/chemokines play an essential role in the pathogenesis of these lesions. Studies with bronchoalveolar lavage demonstrated an increase in neutrophil numbers and the neutrophil chemoattractant interleukin-8. Recent studies demonstrated that T lymphocytes, especially CD8 (+) cells are increased and express a variety of cytokines and chemokines, which are involved in cell infiltration and activation. Studies with gene-engineered animals and anti-cytokine treatment will facilitate better understanding the role of cytokines/chemokines, and eventual novel therapy.