Investigating Nasal and Ocular Immune Response to Conjunctival Allergen Exposure
ConditionAllergic Rhinoconjunctivitis
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-70
SponsorDr. Anne Ellis
About this trial
The goal of this pilot study is to develop an eye allergen challenge model, called a conjunctival allergen challenge (CAC), using timothy grass as the allergen. This model will allow for a more consistent approach to studying allergic rhinoconjunctivitis (allergy of the eye and nose) and help us better understand the connections between the eye and the nose. The two main questions asked in this study are:
1. How can allergic symptoms be safely and accurately produced in a research setting? 2. What are the underlying connections between the eye and the nose, and how do they drive allergic rhinoconjunctivitis?
This study will recruit both timothy grass-allergic participants with a history of eye and nose symptoms and non-allergic participants.
Allergic participants will:
* Be challenged with timothy grass extract diluted in sterile saline using the CAC model, which involves administering the allergen directly to the eye in a manner similar to applying eye drops. * Have nasal fluid and tear samples collected at various timepoints up to 6 hours after CAC exposure. * Complete ocular and nasal symptom questionnaires and assessments by a eye care professional. * Visit the study site 3 separate times:
1. Screening visit (Visit 1): to determine eligibility for the study. 2. CAC visit (Visit 2): to receive allergen exposure, complete symptom questionnaires, and provide study samples. 3. Follow-up (Visit 3): to complete a final symptom questionnaire (24 hours after allergen exposure).
Non-allergic participants will:
* Be challenged with timothy grass extract diluted in sterile saline using the CAC model, administered directly to the eye similarly to eye drops. * Have nasal fluid and tear samples collected at various timepoints up to 6 hours after CAC exposure. * Complete ocular and nasal symptom questionnaires and assessments by a eye care professional. * Visit the study site 3 separate times:
1. Screening visit (Visit 1): to determine eligibility for the study. 2. CAC visit (Visit 2): to receive allergen exposure, complete symptom questionnaires, and provide study samples. 3. Follow-up (Visit 3): to complete a final symptom questionnaire (24 hours after allergen exposure) and receive another CAC and nasal sponge sample for allergen-tracking purposes.
This study will compare the nasal and ocular symptoms and allergic markers collected from tear and nasal fluid samples between allergic and non-allergic participants at baseline and at several timepoints after CAC exposure. It will also measure the concentration of allergen in the nasal sponge samples of non-allergic participants at the follow-up visit to assess how the allergen moves from the eye to the nose.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
A volunteer between the ages of 18 to 70 years of age.
Able to understand and willing to provide written informed consent.
Able and willing to comply with study requirements.
If the participant is a person of childbearing potential, they must practice abstinence or use a medically acceptable method of birth control and produce a negative urine pregnancy test at Visit 1, Visit 2, and Visit 3 (only non-allergic participants will require a pregnancy testing at Visit 3).
Disqualifiers
Participant has a history of any disease or disorder that, in the judgement of the Principal Investigator, would impact on participant's safety or the results of the study.
Participant has a significant history of alcohol or drug abuse in the judgment of the Principal Investigator or delegate.
Participant is pregnant, lactating, or actively trying to become pregnant.
Participant is unable to comply with the washout periods for restricted medications, contact lens use, and smoking.
Trial population
Adults between 18 to 70 years old from the Kingston, Frontenac, Lennox, and Addington regions. Participants on file from previous enrolment in Kingston Allergy Research studies may be eligible for the study, if inclusion/exclusion criteria is met. We aim to recruit 6 timothy grass allergic participants and 6 non-allergic controls.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Standardized Allergen Extract, Timothy Grass (Phleum pratense)
DrugTimothy grass-allergic participants will be exposed to diluted Timothy grass allergen using the CAC model.
Standardized Allergen Extract, Timothy Grass (Phleum pratense)
DrugNon-allergic participants will be exposed to diluted Timothy grass allergen using the CAC model.
Treatment groups
12 Participants
are divided into 2 treatment groupsGroup A: Experimental (Allergic)1 intervention
Group B: Experimental (Non-Allergic)1 intervention
Trial outcomes
Primary outcomes
1
Total Ocular Symptom Score (TOSS)
To evaluate how CAC exposure to timothy grass allergen affects TOSS, which is the total ocular symptom score calculated as the sum of scores for itchy, gritty or burning eyes, watery or tearing eyes, and eye redness. The score ranges from 0, indicating no eye allergy symptoms, to 9, indicating the maximum severity of symptoms. Post-exposure scores will be compared to baseline measurements in allergic participants.
Time frame
Pre-CAC up to 24 hours post-CAC.Secondary outcomes
1
Total Nasal Symptom Score (TNSS)
To evaluate how CAC exposure to timothy grass allergen affects TNSS, which is the total nasal symptom score calculated as the sum of scores for runny nose/post-nasal drip, nasal congestion/stuffiness, sneezing, and itchy nose. The score ranges from 0, indicating no nasal allergy symptoms, to 12, indicating the maximum severity of symptoms. Post-exposure scores will be compared to baseline measurements in allergic participants.
Time frame
Pre-CAC up to 24 hours post-CAC.2
Ear/Palate/Throat symptom score
To evaluate how CAC exposure to timothy grass allergen affects the ear/palate/throat symptom score. The score ranges from 0, indicating no allergy symptoms, to 3, indicating the maximum severity of symptoms. Post-exposure scores will be compared to baseline measurements in allergic participants.
Time frame
Pre-CAC up to 24 hours post-CAC.3
Total Rhinoconjunctivitis Symptom Score (TRSS)
To evaluate how CAC exposure to timothy grass allergen affects TRSS, which is the sum of TNSS and TOSS symptom scores plus ear/palate/throat itching symptoms. The score ranges from 0, indicating no allergy symptoms, to 24, indicating the maximum severity of symptoms. Post-exposure scores will be compared to baseline measurements in allergic participants.
Time frame
Pre-CAC up to 24 hours post-CAC.4
Physician-assessed ocular signs
To evaluate how CAC exposure to timothy grass allergen affects ocular redness, chemosis, and perilimbal injection based on assessment of a physician. Post-exposure scores will be compared to baseline measurements in allergic participants.
Time frame
Pre-CAC up to 6 hours post CAC.Other outcomes
1
Incidence and severity of adverse events
Assessed for their frequency, severity, (mild, moderate, severe) and relationship to the study intervention.
Time frame
Pre-CAC up to 6 hours post CAC.2
Use of rescue medication or medical intervention
Any rescue medication or other medical intervention required to manage symptoms or adverse events following CAC will be recorded, including the type of medication or intervention and the reason it was required.
Time frame
Pre-CAC up to 6 hours post CAC.Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Dr. Anne Ellis
Lead sponsor
Queen's University
Sponsor institution
Source ClinicalTrials.gov