Fundamentals of chronic inflammatory lung diseases (asthma, COPD, fibrosis)

Since three decades the prevalence of chronic inflammatory lung diseases (asthma, COPD, fibrosis) are worldwide increasing. In Switzerland about 5 % of the population develops asthma, while in other countries it affects up to 20 % (Maori: New Zealand). Today, asthma is the most frequent cause from absence from school and work, and significantly reduces life quality of the patients and their families. COPD, or the smoker's lung, is the 4th most frequent cause of death worldwide and in the Western society affects mainly cigarette smokers and ex-smokers, while in developing countries it is a diseases linked to open fire cocking with most patients being middle aged women. In both diseases only the symptoms can be controlled by muscle relaxing and anti-inflammatory drugs, but there is no cure available. The third chronic inflammatory lung disease is fibrosis which is increasing with the aging population. As indicated by the terminology "chronic inflammatory lung disease" it is widely assumed that the major cause of these diseases is chronic inflammation occurring in different segments of the lung. This hypothesis is now challenged as increasing evidence from clinical and experimental studies that suggest a much different pathogenesis. There is evidence that the inflammation may come second and tissue structural changes are already pre-set during embryogenesis and may become the major driver for the development of chronic inflammatory lung diseases later in life. The mechanism of this pre-disposition is largely unknown and the difficult to perform investigations have only started in recent years. This review aims to provide an overview of key studies published in the past 2 years on clinical and experimental research.