Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium

The investigators want to measure and compare sIgE values (kUA/L) towards different pollen samples.

The investigators want to measure and compare basophil degranulation with different pollen extracts on fresh patient-derived basophils. The investigators will use %CD63+ basophils as measure for basophil reactivity and sensitivity. The investigators will compare this between different pollen samples.

The investigators will use an immunoblot to compare IgE mediated reactivity toward different pollen samples. Quantitatively, the investigators will compare band intensity (mean gray value) between different samples.

The investigators will use an immunoblot to compare IgE mediated reactivity toward different pollen samples. Qualitatively, the investigators will compare presence of bands between samples.

The Total Nasal Symptom Score (TNSS) is the sum of scores for each of nasal congestion, sneezing, nasal itching, and rhinorrhea at each time point, using a four point scale (0-3), where 0 indicates no symptoms, a score of 1 for mild symptoms that are easily tolerated, 2 for awareness of symptoms which are bothersome but tolerable and 3 is reserved for severe symptoms that are hard to tolerate and interfere with daily activity. TNSS is calculated by adding the score for each of the symptoms to a total out of 12.

The rhinitis severity Visual analogue scale (VAS) is used to evaluate the overall severity of the rhinitis symptoms. The participant is asked to answer the several questions on: "How troublesome are your symptoms" on a 100mm VAS from 0 ('not troublesome') to 100 ('worst thinkable troublesome'). Based on their score on the VAS, the severity of rhinosinusitis can be divided into 3 categories as follows:

Mild = VAS <20 mm Moderate = VAS 20-50 Severe = VAS >50

Pollen-food syndrome (PFS) validated diagnostic questionnaire evaluates presence and severity of cross-reactivity. The diagnostic questionnaire and algorithm is a practical and robust tool, which enables rapid identification, and therefore management, of individuals with PFS who experience rhino-conjunctivitis symptoms in the birch pollen season. Evaluate association of cross-reactivity with reactivity to different pollen samples.

Stress and well-being: evaluate impact on patients life - Quality of life (EuroQol 5 Dimensions, 5 Levels = EQ-5D-5L). Will be evaluated according to the standard guidelines. A worse rhinitis control and a worse asthma control are associated with higher EQ-5D-5L levels, particularly regarding pain/discomfort and activity impairment. Worse rhinitis control is associated with worse anxiety/depression, and poor asthma control with worse mobility.

The descriptive system comprises 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the 5 dimensions. The digits for the 5 dimensions can be combined into a 5-digit number that describes the patient's health status.

Allergy-Specific Work Productivity and Impairment (including CIQ = Classroom Impairment Questions) questionnaire (WPAI+CIQ: AS). Impaired work productivity has been associated with the severity of allergic rhinitis.

WPAI outcomes are expressed as impairment percentages, with higher numbers indicating greater impairment and less productivity, i.e., worse outcomes.

Scores:

Multiply scores by 100 to express in percentages. Percent work time missed due to allergy: Q3/Q2 Percent impairment while working due to allergy: Q4/10 Percent overall work impairment due to allergy: (Q3/Q2)+[(1-(Q3/Q2))x(Q4/10)] Percent class time missed due to allergy: Q7/Q6 Percent impairment in the classroom due to allergy: Q8/10 Percent overall classroom impairment due to allergy: (Q7/Q6)+[(1-(Q7/Q6))x(Q8/10)] Percent activity impairment due to allergy: Q9/10