2. MATERIALS AND METHODS 2.1. Study population
The study population consisted of 18 adults (12 females and 6 males; age range 23-50 years; mean 34.8 ± 8.2 years). Three non-allergic controls and 15 patients, who suffered from at least one respiratory allergy, were included. Sampling was performed in August. All subjects were asked to stop with all anti-allergic medication for at least a week before sampling. Written informed consent was obtained from all individuals, the study was approved by the medical ethics committee UZA-UA (EC UZA 18/11/154).