5. The patient has shown signs of uncontrolled disease during the last three days, e.g. the patient has required more than four puffs/day of rescue medication above baseline use during the last three days. (In the case criteria 1-4 are not met, such patients may be rescheduled for bronchoscopy in two weeks time. The start of the oral prednisolone intervention will then be postponed by the number of days passing before the bronchoscopy).