Clinical trial NCT06714149: Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium
Official title: Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Pollen Allergy
Keywords: Nitrogen
Pollution
Pollen allergy
Lead sponsor: Universitaire Ziekenhuizen KU Leuven
Sponsor class: OTHER
Collaborators: name: Sciensano
name: KU Leuven
name: University of Namur
name: UniversitÃ© Catholique de Louvain
First posted: 2024-12-03
Enrollment: 200
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Intervention model description: A Cross-Sectional Paired Comparison Study
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Eligibility criteria: Inclusion Criteria:

* Positive skin prick test for grass and/or birch pollen

Exclusion Criteria:

* Desensitization therapy during the last two years

Primary outcomes:
measure: Specific IgE reactivity (in-house developed) against environmental and experimental pollen samples
timeFrame: From time of inclusion to 12 months
Secondary outcomes:
measure: Basophil degranulation with different amounts of pollen on fresh patient-derived basophils.
timeFrame: From time of inclusion to 12 months
measure: Overall intensity (quantitative) of IgE reactivity to pollen samples in a subset of patients.
timeFrame: From time of inclusion to 12 months
measure: IgE-mediated hyper- or hyporecognition of different fragments in the pollen samples (qualitative) in a subset of patients.
timeFrame: From time of inclusion to 12 months
Other outcomes:
measure: Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (TNSS)
timeFrame: From time of inclusion to 12 months
measure: Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (VAS)
timeFrame: From time of inclusion to 12 months
measure: Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (PFS)
timeFrame: From time of inclusion to 12 months
measure: Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (EQ-5D-5L)
timeFrame: From time of inclusion to 12 months
measure: Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (WPAI + CIQ: AS)
timeFrame: From time of inclusion to 12 months
Locations:
city: Leuven
country: Belgium
facility: University Hospitals Leuven
state: Vlaams-Brabant
Study officials:
References:
citation: 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.
citation: 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.