Surprise: Bronchoconstriction (not just inflammation) causes airway remodeling in asthma

Grainge et al collected bronchial biopsies from 48 allergic asthmatics, then randomly gave them either inhaled dust mite allergen; methacholine; saline (control); or albuterol followed by methacholine (control). Those inhaling allergen or methacholine had immediate bronchoconstriction, followed by an increase in bronchial wall thickness (on repeat bronchial biopsy 4 days later) compared to controls. Dogma has it that chronic inflammation, not intermittent bronchoconstriction, induces airway remodeling.

These findings don't establish the real-life extent and consequences of bronchoconstriction-induced remodeling, but could boost the rationale for long-acting beta agonists as chronic asthma therapy. (n=48) NEJM 2011;364:2006-2015.