Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Immunoreactivity testing, Immunoreactivity testing (negative control).
- Who it may be relevant to
- Registry conditions: Pollen Allergy. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Belgium
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
The investigators want to study the effect of environmental nitrogen enrichment on the allergy burden in pollen-sensitized subjects.
Detailed description
The investigators want to study allergen-specific IgE reactivity from a cross-sectional sample of pollen-allergic patients (and negative controls) against environmental and experimental pollen samples. Following aspects will be compared:
* To study the basophil degranulation with different amounts of pollen on fresh patient-derived basophils, to determine the concentration of pollen needed to degranulate 5% (EC5), and 50% (EC50) of basophils. * To study he overall intensity (quantitative), as well as IgE-mediated hyper- or hyporecognition of different fragments in the pollen samples (qualitative) in a subset of patients. * To associate allergic rhinoconjunctivitis and food-pollen syndrome related symptoms with reactivity to different pollen samples.
Interventions
- Diagnostic test Immunoreactivity testing
Blood samples will be collected and used to determine the intensity of the allergenicity of the subject toward different types of pollen. This will be done by the detection of sIgE antibodies to the pollen extracts and basophil activation testing (BAT) with pollen extracts. - Diagnostic test Immunoreactivity testing (negative control)
Blood samples will be collected and used to determine the background activity of our immunoreactivity tests. The investigators will use samples from negative controls to demonstrate that non-allergic individuals do not react to our assays, confirming that our pollen extracts have no background reactivity. This will be done by the detection of sIgE antibodies to the pollen extracts and basophil activation testing (BAT) with pollen extracts.
Primary outcome measures
- Specific IgE reactivity (in-house developed) against environmental and experimental pollen samples [Time frame: From time of inclusion to 12 months]
Secondary outcome measures (3)
- Basophil degranulation with different amounts of pollen on fresh patient-derived basophils. [Time frame: From time of inclusion to 12 months]
- Overall intensity (quantitative) of IgE reactivity to pollen samples in a subset of patients. [Time frame: From time of inclusion to 12 months]
- IgE-mediated hyper- or hyporecognition of different fragments in the pollen samples (qualitative) in a subset of patients. [Time frame: From time of inclusion to 12 months]
Eligibility criteria
Inclusion criteria
- Positive skin prick test for grass and/or birch pollen
Exclusion criteria
- Desensitization therapy during the last two years
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Basic science
Study locations
Belgium · 1 center
- University Hospitals Leuven — Leuven
Publications
- Verscheure P, Honnay O, Speybroeck N, Daelemans R, Bruffaerts N, Devleesschauwer B, Ceulemans T, Van Gerven L, Aerts R, Schrijvers R. Impact of environmental nitrogen pollution on pollen allergy: A scoping review. Sci Total Environ. 2023 Oct 1;893:164801. doi: 10.1016/j.scitotenv.2023.164801. Epub 2023 Jun 14. PMID 37321510
- Ceulemans T, Verscheure P, Shadouh C, Van Acker K, Devleesschauwer B, Linard C, Dendoncker N, Speybroeck N, Bruffaerts N, Honnay O, Schrijvers R, Aerts R. Environmental degradation and the increasing burden of allergic disease: The need to determine the impact of nitrogen pollution. Front Allergy. 2023 Feb 2;4:1063982. doi: 10.3389/falgy.2023.1063982. eCollection 2023. No abstract available. PMID 36819832
Identifiers
NCT: NCT06714149 · S65184 · B2/212/P1/NITROPOL-BE