Effects of asthma treatment on airway remodeling
Surprisingly little is really known about airway remodeling in asthma, including its clinical course, or how treatment may modify it. Two examples: rather than occurring as a late sequela of unchecked inflammation, numerous recent studies show remodeling can occur in tandem with inflammation starting in early childhood. A recent NEJM article generates the hypothesis that bronchoconstriction alone could cause some airway remodeling.
This remarkable review by Durrani et al separates the lore from what is known: mainly that sustained high doses of inhaled corticosteroids do seem to attenuate airway remodeling (mainly basement membrane thickness). Their most interesting point is that according to current treatment guidelines, most of the patients in the cited trials would today have their steroids tapered prior to receiving the benefit of remodeling prevention. That's because symptoms are controlled before the remodeling attenuation occurs, they argue.
Whether the benefits of preventing airway remodeling (in the subset of patients who will develop it) outweigh any adverse effects of prolonged high-dose ICS administered widely, is anyone's guess, they acknowledge.
Durrani SR et al. What effect does asthma treatment have on airway remodeling? Current perspectives. J Clin All Immunol 2011;128:439-448. (FREE FULL TEXT, FREE CME CREDIT)