Pollen AllergyNITROPOL-BENCT06714149
Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium
A study testing Immunoreactivity testing in people with Pollen Allergy, run by prof. dr. Rik Schrijvers at 1 site in Belgium.
Trial summary
The investigators want to study the effect of environmental nitrogen enrichment on the allergy burden in pollen-sensitized subjects. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Pollen Allergy
- What is being tested?
- Immunoreactivity testing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 200 participants
- Where
- 1 siteBelgium
- Study dates
- 29 Jun 2022to Apr 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Positive skin prick test for grass and/or birch pollen
Who cannot join
- Desensitization therapy during the last two years
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Raf Aerts, PhD contact
Belgium1 site, 1 recruiting
- Recruiting
University Hospitals Leuven
Leuven, Vlaams-Brabant, 3000
Paulien Verscheure, MSc, +3216338861, paulien.verscheure@kuleuven.be
About this study
The investigators want to study the effect of environmental nitrogen enrichment on the allergy burden in pollen-sensitized subjects.
Read the 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.
- Conditions
- Pollen Allergy
- Being tested
- Immunoreactivity testing, Immunoreactivity testing (negative control)
- Keywords
- Nitrogen, Pollution, Pollen allergy
- Medical subject headings
- Rhinitis, Allergic, Seasonal
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Immunoreactivity testingDiagnostic 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.
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.
| Study group | Role | What they receive |
|---|---|---|
| Allergic subjects | Other | All subject with positive skin prick testing for grass and/or birch pollen are assigned to this group. Receives: 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. Receives: Diagnostic Test: Immunoreactivity testing (negative control) |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: From time of inclusion to 12 months
Secondary outcomes (3)
Basophil degranulation with different amounts of pollen on fresh patient-derived basophils.
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.
Measured: From time of inclusion to 12 months
Overall intensity (quantitative) of IgE reactivity to pollen samples in a subset of patients.
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.
Measured: 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.
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.
Measured: From time of inclusion to 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Dec 2024
- Study start29 Jun 2022
- Primary completionFeb 2025 (estimated)
- Study completionApr 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Pollen AllergyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- A Cross-Sectional Paired Comparison Study
- Masking
- None (open label)
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- prof. dr. Rik Schrijvers
- Sponsor type
- University, hospital or other
- Collaborators
- Sciensano, KU Leuven, University of Namur, Université Catholique de Louvain
- Responsible party
- Sponsor-investigator, prof. dr. Rik Schrijvers, Universitaire Ziekenhuizen KU Leuven
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06714149
- Sponsor's protocol ID
- S65184
- Other IDs
- B2/212/P1/NITROPOL-BE
- Acronym
- NITROPOL-BE
- Status last verified
- Dec 2024
- First submitted
- 20 Nov 2024
- Last updated
- 3 Dec 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
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.
PubMed 37321510Ceulemans 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.
PubMed 36819832
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impacts of Nitrogen Deposition in the Natural Environment on Pollen Allergy in Belgium
- ClinicalTrials.gov ID
- NCT06714149
- Acronym / sponsor ID
- NITROPOL-BE / S65184
- Conditions
- Pollen Allergy
- Keywords
- Nitrogen, Pollution, Pollen allergy
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- prof. dr. Rik SchrijversUniversity, hospital or other
- Collaborators
- Sciensano, KU Leuven, University of Namur, Université Catholique de Louvain
- Study start
- 29 Jun 2022 (actual)
- Primary completion
- Feb 2025 (estimated)
- Study completion
- Apr 2025 (estimated)
- First posted
- 3 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A Cross-Sectional Paired Comparison Study
| Arm | Type | Receives |
|---|---|---|
| Allergic subjects | Other | Diagnostic Test: Immunoreactivity testingAll subject with positive skin prick testing for grass and/or birch pollen are assigned to this group. |
| Healthy controls | Other | Diagnostic Test: Immunoreactivity testing (negative control)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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Positive skin prick test for grass and/or birch pollen
Key exclusion criteria (1 listed)
- Desensitization therapy during the last two years
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Immunoreactivity testingBlood 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 | Allergic subjects |
| 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. | Diagnostic test | Healthy controls |
Primary outcome
Specific IgE reactivity (in-house developed) against environmental and experimental pollen samples
Time frame: From time of inclusion to 12 months
The investigators want to measure and compare sIgE values (kUA/L) towards different pollen samples.
3 secondary outcomes
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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Dec 2024.
- Background: PubMed 37321510Verscheure 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.
- Background: PubMed 36819832Ceulemans 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Raf Aerts, PhD contact
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Immunoreactivity testing in people with Pollen Allergy, run by prof. dr. Rik Schrijvers at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 3 Dec 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rik Schrijvers, MD, PhD (+3216342985, rik.schrijvers@uzleuven.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Specific IgE reactivity (in-house developed) against environmental and experimental pollen samples (time frame: From time of inclusion to 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06714149, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Dec 2024.