Asthma is associated with a specific inflamma¬tory state of the airways. Assuming that the degree of airway inflammation is a determinant for the long-term disease outcome, it follows that, asthma therapy should be aimed at maximal reduction of airway inflammation, in addition to reducing symptoms. However, according to current guidelines, therapy should only be directed to the clinical severity of the disease. There is increasing evidence that bronchial hyper¬respon¬siveness can be used as a non-invasive reflection of airway inflamma¬tion [29]. However, it is still unknown whether bronchial responsiveness provides relevant additional information for adjusting therapy during follow-up of patients with asthma. Therefore, in this study we will: