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

NCT ID: NCT06714149

Last Updated: 2024-12-03

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

200 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-06-29

Study Completion Date

2025-04-30

Brief Summary

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The investigators want to study the effect of environmental nitrogen enrichment on the allergy burden in pollen-sensitized subjects.

Detailed Description

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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.

Conditions

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Pollen Allergy

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

A Cross-Sectional Paired Comparison Study
Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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Allergic subjects

All subject with positive skin prick testing for grass and/or birch pollen are assigned to this group.

Group Type OTHER

Immunoreactivity testing

Intervention Type DIAGNOSTIC_TEST

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.

Healthy controls

Subjects with negative skin prick testing for grass and/or birch pollen are assigned to this group and used for as negative controls in our experiments.

Group Type OTHER

Immunoreactivity testing (negative control)

Intervention Type DIAGNOSTIC_TEST

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.

Interventions

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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.

Intervention Type 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.

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

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

Exclusion Criteria

* Desensitization therapy during the last two years
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Sciensano

OTHER_GOV

Sponsor Role collaborator

KU Leuven

OTHER

Sponsor Role collaborator

University of Namur

OTHER

Sponsor Role collaborator

Université Catholique de Louvain

UNKNOWN

Sponsor Role collaborator

prof. dr. Rik Schrijvers

OTHER

Sponsor Role lead

Responsible Party

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prof. dr. Rik Schrijvers

Prof. dr.

Responsibility Role SPONSOR_INVESTIGATOR

Locations

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University Hospitals Leuven

Leuven, Vlaams-Brabant, Belgium

Site Status RECRUITING

Countries

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Belgium

Central Contacts

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Rik Schrijvers, MD, PhD

Role: CONTACT

+3216342985

Raf Aerts, PhD

Role: CONTACT

Facility Contacts

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Paulien Verscheure, MSc

Role: primary

+3216338861

References

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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.

Reference Type BACKGROUND
PMID: 37321510 (View on PubMed)

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.

Reference Type BACKGROUND
PMID: 36819832 (View on PubMed)

Other Identifiers

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B2/212/P1/NITROPOL-BE

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

S65184

Identifier Type: -

Identifier Source: org_study_id