The Role of Filaggrin Mutations and Sensitization Pathways in Allergic Rhinitis and Peanut Allergy

November 28, 2023 updated by: Dr. Anne Ellis

Deconstructing the Atopic March - the Role of Filaggrin Mutations and Sensitization Pathways in Allergic Rhinitis and Peanut Allergy

Caucasian male and female participants age 18 years of age and older will be enrolled in this study if they have known birch or peanut allergies or known to be non-atopic. Participants will undergo skin testing to confirm their allergies if not completed in the last 12 months. Medications and medical history will be captured with a focus on atopic disorders. Participants will undergo birch and peanut patch testing to assess penetration and if potential correlation exists with filaggrin genotyping and phenotyping. Blood samples will be drawn from participants and DNA isolated for genotyping of null mutations in filaggrin.

Study Overview

Status

Recruiting

Detailed Description

Participants with confirmed history of birch induced allergic rhinitis or peanut allergy or that are non-atopic will undergo the following procedures.

If not already completed in the previous year, participants will be skin tested to a panel of common environmental allergens, including birch pollen and peanut. To be considered "non-atopic", all skin tests in the panel must be negative in the presence of a positive histamine control. All participants will also be skin tested to peanut, Arah 2, Ara h 8 (if obtainable), crushed raw unroasted peanut, peanut butter, peanut extract, Bet v 1 and birch pollen extract.

Blood samples will be drawn for genotyping of the four most common null mutations in FLG in Caucasians (R501X, 2282del4, R2447X, S3247X).

Patch testing will be performed using Ara h2, Arah8 (if obtainable), crushed raw unroasted peanut, peanut butter, peanut extract, Bet v 1 and birch pollen extract. Peanut and birch pollen allergens, both whole and components will be diluted 1:10 in both saline and petroleum jelly and applied to normal controls skin to establish levels for irritant reaction. If further dilutions are required to show non-irritation these will be performed.

As well, a limited medical history and medication history will be documented, with a focus on atopic disorders (i.e. atopic dermatitis (eczema), allergic rhinitis, asthma, and food allergy). Those in the non-allergic control group will be excluded if they have features of eczema, food allergy or other atopic conditions). Medications that could potentially interfere with the skin test results (i.e. antihistamines) must be documented, and appropriate washout intervals observed prior to the skin test procedure, if necessary.

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Ontario
      • Kingston, Ontario, Canada, K7L2V7
        • Recruiting
        • Kingston General Hospital
        • Contact:
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Caucasian male and female participants 18 years of age and older with birch or peanut allergies as well as non-atopic controls will be enrolled in this study.

Description

Inclusion Criteria:

  • caucasian male or females
  • participants 18 years of age and older
  • participants with known birch allergy, confirmed by a skin test 3mm or greater than the negative control
  • participants with diagnosed and confirmed peanut with allergy
  • confirmed by one of the following:
  • positive food challenge
  • convincing history of peanut allergy AND positive skin test (3mm >= than negative control) OR peanut-specific IgE >=0.35
  • uncertain history of peanut allergy OR no exposure to peanut AND a positive skin test 5mm>= negative control AND a peanut-specific IgE >=15
  • non-allergic controls who lack a diagnosis of any atopic diathesis and have supportive negative skin testing to a panel of common environmental allergens.

Exclusion criteria:

  • participants unable to complete study related procedures
  • participants that have taken or are taking restricted medications

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Other
  • Time Perspectives: Cross-Sectional

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Peanut patch testing
Time Frame: Up to 17 months

Differences in patch test positive responses to peanut allergen (extract plus raw peanut butter preparations) between participants with confirmed peanut allergy, confirmed birch allergy and non-atopic controls.

Responses are graded as:

Negative (-) Irritant reaction (IR) Equivocal / uncertain (+/-) Weak positive (+) Strong positive (++) Very Strong Positive (+++)

Up to 17 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Birch patch testing
Time Frame: Up to 17 months

Differences in patch test positive responses to birch allergen extract between participants with confirmed peanut allergy, confirmed birch allergy and non-atopic controls.

Responses are graded as:

Negative (-) Irritant reaction (IR) Equivocal / uncertain (+/-) Weak positive (+) Strong positive (++) Very Strong Positive (+++)

Up to 17 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Relationship of peanut and birch patch testing responses to filaggrin genotype
Time Frame: Up to 17 months
Presence or absence of positive patch tests to birch and peanut and correlation of these responses with filaggrin genotypes.
Up to 17 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Anne K Ellis, MD, Queen's University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2016

Primary Completion (Estimated)

November 1, 2023

Study Completion (Estimated)

December 1, 2023

Study Registration Dates

First Submitted

March 2, 2016

First Submitted That Met QC Criteria

April 19, 2016

First Posted (Estimated)

April 20, 2016

Study Record Updates

Last Update Posted (Actual)

November 30, 2023

Last Update Submitted That Met QC Criteria

November 28, 2023

Last Verified

November 1, 2023

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Allergic Rhinitis

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