C1-inhibitor in Allergic ASThma Patients

Intravenous administration of C1-inhibitor (n=20) or vehicle (n=20). One group of patients (n=20) will receive broad spectrum antibiotics (vancomycin, ciprofloxacin, metronidazole) for 7 days (washout 36 hours before study day). This group will receive the same vehicle as the control group 2 hours prior to challenge. HDM will be administered together with the environmental pollutant LPS in a lung subsegment via a bronchoscope (mimicking environmental exposure to HDM); a contralateral lung subsegment will be administered with saline (control side). After 7 hours, bronchoalveolar lavage (BAL) fluid will be harvested by a second bronchoscopy. Blood samples will be collected before administration of C1-inhibitor or vehicle, and before both bronchoscopies. Faeces will be collected prior to antibiotic administration as well as prior to HDM+LPS challenge.