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

NCT06714149 | Recruiting

• 2 other identifiers: S65184B2/212/P1/NITROPOL-BE
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

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

Conditions

Pollen Allergy

Keywords

Nitrogen; Pollution; Pollen allergy

Outcome Measures

Primary Outcomes (1)

• Specific IgE reactivity (in-house developed) against environmental and experimental pollen samples

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

  From time of inclusion to 12 months

Secondary Outcomes (3)

• Basophil degranulation with different amounts of pollen on fresh patient-derived basophils.

  From time of inclusion to 12 months

• Overall intensity (quantitative) of IgE reactivity to pollen samples in a subset of patients.

  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.

  From time of inclusion to 12 months

Other Outcomes (5)

• Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (TNSS)

  From time of inclusion to 12 months

• Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (VAS)

  From time of inclusion to 12 months

• Association of allergic rhinoconjunctivitis symptoms with reactivity to different pollen samples (PFS)

  From time of inclusion to 12 months

Study Arms (2)

Allergic subjects

OTHER

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

Diagnostic Test: Immunoreactivity testing

Healthy controls

OTHER

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.

Diagnostic Test: Immunoreactivity testing (negative control)

Interventions

Immunoreactivity testing 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.

Allergic subjects

Immunoreactivity testing (negative control) 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.

Healthy controls

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• Desensitization therapy during the last two years

Sponsors & Collaborators

• prof. dr. Rik Schrijvers: lead
• Sciensano: collaborator
• KU Leuven: collaborator
• University of Namur: collaborator
• Université Catholique de Louvain: collaborator

Study Sites (1)

University Hospitals Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

RECRUITING

Related Publications (2)

• 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 BACKGROUND

• 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 BACKGROUND

MeSH Terms

Conditions

Rhinitis, Allergic, Seasonal

Condition Hierarchy (Ancestors)

Rhinitis, Allergic; Rhinitis; Nose Diseases; Respiratory Tract Diseases; Respiratory Hypersensitivity; Otorhinolaryngologic Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Central Study Contacts

Rik Schrijvers, MD, PhD

CONTACT

+3216342985; rik.schrijvers@uzleuven.be

Raf Aerts, PhD

CONTACT

raf.aerts@sciensano.be

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof. dr.

Model Details: A Cross-Sectional Paired Comparison Study

Study Record Dates

• First Submitted: November 20, 2024
• First Posted: December 3, 2024
• Study Start: June 29, 2022
• Primary Completion: February 1, 2025
• Study Completion: April 1, 2025
• Last Updated: December 3, 2024

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)