Corticosteroid resistance in chronic obstructive pulmonary disease: new uses of theophylline

Chronic obstructive pulmonary disease (COPD) is a major global health problem with a rising morbidity and mortality,which is expected to account for about 27％ of tobacco related deaths and is anticipated to move from the fifth to the fourth leading cause of death worldwide from 2002 to 2030.1 COPD is characterized by the abnormal and chronic inflammation induced by cigarette smoking and other inflammatory insults in both small airway and lung parenchyma.2,3 Glucocorticosteroids (also called glucocorticoids,corticosteroids or steroids) are the most effective anti-inflammatory drugs available for the treatment of many chronic inflammatory and immune diseases.4 However,corticosteroids have limited benefit in treating stable COPD5 defined as (relative) steroid insensitivity or resistance6 and may be characteristic of all phenotypes of COPD.Although anti-inflammatory treatments are expected to effectively treat inflammation of COPD,almost all anti-inflammatory approaches risk increasing the extent of infection by blunting host defence mechanisms.Their effectiveness in humans has been limited by various side effects.5 Therefore,it is important to develop a treatment to enhance corticosteroid anti-inflammatory action in COPD.