Study participants
The study population consisted of 20 subjects (mean [SD] age, years
(range); 28.0 [7.1] (19-46); ten men and ten women) suffering from
seasonal allergic rhinitis to grass pollen. The study was approved by
the local Research Ethics Committee. Informed written consent was
obtained from all subjects before their participation.
Inclusion criteria were a history of summer grass pollen allergic
rhinitis for at least 2 years confirmed by a positive skin prick test to
grass pollen extract (Stallergenes) i.e. >3 mm weal
compared with the negative control and positive specific IgE-antibodies
to grass pollen, assessed by Phadia (mean [SD], kU/L (range); 16.5 ±
23.4 (0.4 -100). Patients were excluded if they had current symptoms of
rhinitis, other nasal or systemic disease, asthma requiring regular
inhaled corticosteroids, abnormal pulmonary function, other respiratory
conditions, current medication including anti-allergic medication,
specific immunotherapy in the previous 5 years, smoking history in the
past 6 months, were pregnant or breastfeeding women. None of the
subjects had exposure to other relevant respiratory allergens and to
avoid natural allergen provocation, all subjects were studied outside
the grass-pollen season. At screening, participants were examined,
including a nasal examination to rule out any nasal disease or evidence
of active rhinitis. Throughout the whole study period, subjects were not
allowed to take any medication.