Wang H, et al. - In patients with asthma and COPD, researchers looked for the predictors of failure of Salbutamol to protect against saline-induced-bronchoconstriction while sputum induction with hypertonic saline, as well as assessed implications for asthma therapy. A subgroup was re-examined 8–12 weeks after decreasing long-acting-beta-2-agonist dose or after adding Montelukast, which included an assessment of mast cell activity in sputum. Of 3565 patients, inhaled Salbutamol failed to prevent saline-induced-bronchoconstriction in 222 (6.2%). Predictors of saline-induced-bronchoconstriction included baseline airflow obstruction and long-acting-beta-agonist use, but not bronchitis. The decrease in long-acting-beta-agonist dose was accompanied by decreased saline-induced-bronchoconstriction. Refractoriness to subsequent bronchodilation was found to be related to mast cell activity and was attenuated by Montelukast. Overall, sputum induction with saline offers information on bronchitis and additional physiological data on tolerance to beta-agonists and mast cell activity that may have implications for clinical therapy.