Airway reversibility and inflammation in stable pre- to late-adolescent asthmatics without long-term control medications.

Pulmonary function and airway inflammation were investigated in stable pre- to late-adolescent asthmatics without long-term control medications and compared with those in currently medicated asthmatics. Subjects comprised 34 well-controlled asthmatic children (aged 8.1-18.0 years; group without medication). Flow volume curves before and after inhaling a β2 agonist, a bronchodilator (BD), were compared and fractional exhaled nitric oxide (FENO) concentrations were measured. All patients were attack-free for at least 12 months prior to testing without the use of asthma medications for at least three months. Fifty-one age-matched stable asthmatics with medications at the time of the present study (group with current medication) underwent the same examinations. The rate of children whose respiratory function after BD improved by 20% or more in both the central and peripheral airways (High responder at total airways subtype: HTA) was significantly higher in the group without medication than in that with current medication (17.6 and 2.0%, respectively;  < 0.01). Furthermore, FEV% pred after BD was significantly lower for HTA than for the low responder subtype in the same group (94.8 ± 3.5 and 104.1 ± 1.5% respectively,  < 0.05). FENO concentrations in the group without medication were high, but not significantly different from those in the group with current medication. Stable asthmatic children without medication include a certain percentage of those with irreversible airflow limitation possibly due to airway remodeling. The control of daily asthma symptoms with long-term control medications may effectively prevent airway remodeling.