Can inhaled corticosteroids influence the natural history of asthma?
OBJECTIVE
Asthma is characterised by variable airflow obstruction, airway inflammation and hyper-responsiveness. Persistent inflammation is thought to lead to 'remodelling' of the airway, which in turn leads to the progressive loss of lung function seen in asthmatics. It would appear logical that anti-inflammatory drugs such as inhaled corticosteroids (ICS) would influence the natural history of asthma by reducing inflammation, subsequent remodelling, and thus preventing the decline in lung function. This review will summarise the effects of ICS on the secondary prevention of asthma, lung function and remodelling.


RESULTS
Many published studies show a reduction in airway inflammation, improvement in clinical symptoms and prebronchodilator lung function whilst taking ICS. Few studies, however, examine their effect on the natural history of asthma. Several recent studies have targeted very young children with asthma using ICS, and despite their differing target populations and treatment strategies, have failed to show any difference in lung function. Studies in adults with mild persistent asthma show similar findings. ICS appear to reverse some of the processes involved in airway remodelling, but not all.


CONCLUSIONS
Although ICS are effective in controlling symptoms they do not appear to alter the natural history of asthma.
Murray
Clare S
CS
School of Translational Medicine, Respiratory Group, University of Manchester, ERC, University Hospital of South Manchester NHS Foundation Trust, Manchester, UK. clare.murray@manchester.ac.uk
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use*; D000328:Adult; D000367:Age Factors; D000402:Airway Obstruction / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D001249:Asthma / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology* / Q000517:prevention & control*; D019819:Budesonide / Q000627:therapeutic use; D002648:Child; D006801:Humans; D007223:Infant; D012143:Respiratory Physiological Phenomena / Q000187:drug effects*
D000305:Adrenal Cortex Hormones; D019819:Budesonide