Structural basis for airflow limitation in chronic obstructive pulmonary disease

The airflow limitation that characterises chronic obstructive pulmonary dis ease (COPD) has two main components: an increased resistance, which is due to airway obstruction, and a loss of the elastic recoil pressure of the lun g, which is due to parenchymal destruction, Although it has long been known that the major site of increased resistance in COPD is the peripheral airw ays, recent studies have shown that central airways are involved in the dis ease as well. The purpose of this review is to describe the major structura l and cellular changes present in peripheral airways, central airways and l ung parenchyma of patients with COPD, and to underline the possible mechani sms contributing to airflow limitation in these subjects.