Investigating Nasal and Ocular Immune Response to Conjunctival Allergen Exposure

NCT07801625 | Recruiting

• 1 other identifier: INQUIRE-001
• Study Type: observational
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

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:

• 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:
• Screening visit (Visit 1): to determine eligibility for the study.
• CAC visit (Visit 2): to receive allergen exposure, complete symptom questionnaires, and provide study samples.
• Follow-up (Visit 3): to complete a final symptom questionnaire (24 hours after allergen exposure).
• 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:
• Screening visit (Visit 1): to determine eligibility for the study.
• CAC visit (Visit 2): to receive allergen exposure, complete symptom questionnaires, and provide study samples.
• 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.

Conditions

Allergic Rhinoconjunctivitis

Keywords

Allergic rhinoconjunctivitis; Allergic rhinitis; Allergic conjunctivitis; Timothy grass; Tree pollen; Conjunctival allergen challenge; CAC; Nasolacrimal duct; Ocular allergies; Nasal allergies; Seasonal allergies

Outcome Measures

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.

  Pre-CAC up to 24 hours post-CAC.

Secondary Outcomes (15)

• Total Nasal Symptom Score (TNSS)

  Pre-CAC up to 24 hours post-CAC.

• Ear/Palate/Throat symptom score

  Pre-CAC up to 24 hours post-CAC.

• Total Rhinoconjunctivitis Symptom Score (TRSS)

  Pre-CAC up to 24 hours post-CAC.

• Physician-assessed ocular signs

  Pre-CAC up to 6 hours post CAC.

• Concentrations of alarmins (IL-25, IL-33, TSLP) from nasal sponge samples

  Baseline, 1 hour, 3 hours, and 6 hours post-CAC.

Other Outcomes (2)

• Incidence and severity of adverse events

  Pre-CAC up to 6 hours post CAC.

• Use of rescue medication or medical intervention

  Pre-CAC up to 6 hours post CAC.

Study Arms (2)

Experimental (Allergic)

Allergic Participant Timothy Grass Challenge

Drug: Standardized Allergen Extract, Timothy Grass (Phleum pratense)

Experimental (Non-Allergic)

Non-Allergic Participant Timothy Grass Challenge

Drug: Standardized Allergen Extract, Timothy Grass (Phleum pratense)

Interventions

Standardized Allergen Extract, Timothy Grass (Phleum pratense) DRUG

Timothy grass-allergic participants will be exposed to diluted Timothy grass allergen using the CAC model.

Experimental (Allergic)

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study 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.

You may qualify if:

• All participants must be:
• 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).
• To be enrolled as an allergic participant, participants must:
• Have a minimum 2-year history of grass-specific allergic rhinoconjunctivitis symptoms upon exposure to the relevant allergen, documented by medical history review at Visit 1.
• Have a positive skin prick test response to Timothy grass allergen, defined as a wheal diameter ≥ 5 mm compared to the negative control wheal. This test must be performed by the study team either at the Visit 1 or historically within 1 year of Visit 1 at our research site.
• Have a reported ocular itch ≥2, self-reported ocular redness ≥2, and ophthalmologist/optometrist confirmation of ocular redness (using slit lamp) ≥2 following CAC at Visit 1.
• To be enrolled as a non-allergic participant, participants must:
• Produce a negative skin prick test response to a panel of relevant aeroallergens tested at Visit 1 or within 1 year prior to Visit 1 at our research site.
• Produce a negative CAC, defined by an ocular itch = 0, self-reported ocular redness ≤1, and ophthalmologist/optometrist confirmation of ocular redness (using slit lamp) ≤1 after 10 minutes in response to the lowest (1:512), moderate (1:32) and highest (1:4) concentrations of allergen at Visit 1.

You may not qualify if:

• Participants presenting with any of the following will not be included in the study:
• 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.
• Participant has signs/symptoms of active seasonal AR or is allergic to a seasonal allergen that is present in the outdoor environment during the time of the screening and CAC visits and which the Principal Investigator judges would impact the outcome of the study. If the schedule allows the participant can be re-scheduled for the visit outside the allergy season.
• Participant has any structural nasal abnormalities, nasal polyps on examination, or a history of frequent nose bleeding, as determined by a nasal examination at screening and prior to the CAC, in the judgement of the Principal Investigator or delegate.
• Participant has a history or clinically significant findings during the ocular examination of ocular abnormalities (e.g., meibomian gland dysfunction, moderate to severe dry eyes, cicatrizing conjunctivitis, glaucoma) that may affect the outcome of the study in the judgement of the Investigator.
• Participant has abnormalities detected on physical examination considered by the Principal Investigator to be clinically significant.
• Participant has undergone nasal surgery within the 3 months before Visit 1.
• Participant has undergone ocular surgery within the 3 months before Visit 1.
• Participant has experienced or exhibits any signs or symptoms of an upper respiratory tract infection within 14 days prior to any visit.\*
• Participant reports a TNSS ≥4 prior to the titration challenge at Visit 1 or immediately prior to allergen challenge at Visit 2, as per PI judgement.\*\*
• Participant reports ocular itch \> 0 and ocular redness \> 1 and ophthalmologist/optometrist reported redness \> 1 (using slit lamp) in either eye prior to allergen challenge at any visit.
• Participant reports a TNSS change \> 2 from baseline, after the negative control and diluent challenge at Visit 1.

Sponsors & Collaborators

• Dr. Anne Ellis: lead

Study Sites (1)

Kingston Health Sciences Centre - Kingston General Hospital

Kingston, Ontario, K7L 2V7, Canada

RECRUITING

MeSH Terms

Conditions

Rhinitis, Allergic; Conjunctivitis, Allergic; Rhinitis, Allergic, Seasonal

Condition Hierarchy (Ancestors)

Rhinitis; Nose Diseases; Respiratory Tract Diseases; Respiratory Hypersensitivity; Otorhinolaryngologic Diseases; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases; Conjunctivitis; Conjunctival Diseases; Eye Diseases

Study Officials

• Anne K Ellis, MD

  Queen's University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Lisa Steacy, BSc

CONTACT

(613) 549-6666; lisa.steacy@kingstonhsc.ca

Sarah Garvey, RPN

CONTACT

(613) 549-6666; sarah.garvey@kingstonhsc.ca

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 8 Weeks
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Dr. Anne K. Ellis, MD

Study Record Dates

• First Submitted: August 31, 2026
• First Posted: September 3, 2026
• Study Start: September 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: October 1, 2026

Record last verified: 2026-08

Locations

CA (1)