Respiratory medicine

lthough the fight to reduce the incidence of lung disease and respiratory conditions is far from over, recent advances in the treatment of chronic obstructive pul-monary disease (COPD) and asthma are giving hope to both patients and physicians. Chronic obstructive pulmonary disease Despite the incontrovertible evidence that cigarette smoking is responsible for lung cancer and COPD, smoking continues unabated in industrialized nations and is increasing at alarming rates in developing nations. In a recent study of the global burden of disease, COPD was ranked the 12th most important contributor to disability-adjusted life-years worldwide and was projected to rank 5th by the year 2020.1 Pul-monary emphysema, which is characterized by destruction of the lung surface and loss of alveoli, is a major consequence of smok-ing and the most im-portant cause of the airflow limitation that defines COPD. In em-physema the lung’s elastin fibre network is disrupted, a process that has been accepted as irreversible. However, 2 recent studies have suggested that the concept of irreversibility needs to be re-exam-ined. Massaro and Massaro2 used retinoic acid to reverse emphysema that had been induced in rats with the pro-teolytic enzyme elastase. Retinoic acid plays an important role in regulating alveolar septation in the developing lung of the fetus, but the concept that it might aid in stimulating the formation of new alveoli in mature lung tissue is novel and exciting. Although public health poli-cies designed to decrease the prevalence of cigarette smoking remain the most important means of preventing COPD, it may not be long before we see clinical trials examining whether lungs partially destroyed by emphy-sema can be repaired. Additional evidence that loss of elastin is not irreversible comes from studies showing that new elastin can be synthesized and damaged elastin repaired by lung interstitial fibroblasts.3 Asthma Asthma is the most common respiratory illness after the common cold, affecting about 5 % of adults and about 10 % of children. The increasing incidence and preva-lence of asthma, along with other atopic diseases (such as allergic rhinitis and eczema), prompted the Ciba Foun-dation to sponsor an international guest symposium in 1997 to address the reasons fo