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The Effect of Extrinsic Factors on Food Allergy (Ex-Factor)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified January 2015 by Dr. Andrew Clark, Cambridge University Hospitals NHS Foundation Trust.
Recruitment status was:  Recruiting
Sponsor:
ClinicalTrials.gov Identifier:
NCT01429896
First Posted: September 7, 2011
Last Update Posted: January 14, 2015
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborators:
Imperial College London
University of Manchester
Information provided by (Responsible Party):
Dr. Andrew Clark, Cambridge University Hospitals NHS Foundation Trust
  Purpose

Food allergy is a common problem, affecting 5-8% of the population. Peanut allergy causes reduced quality of life due to the perceived high risk of severe reactions. Patients rely on accurate labeling of both loose and pre-packed foods, but these are often ambiguous and unhelpful. There is a common conception that labeling is 'over-cautious'. Peanut-allergic consumers face increasingly restricted food choices in complying with this advice due, in part, to the proliferation of advisory labels such as 'may contain peanuts'. This contributes to the reduces quality of life of affected individuals.

For industry to provide more accurate and helpful labeling, certain characteristics of the food-allergic population need to be defined. Firstly, the minimum 'eliciting dose' for the population has been estimated by studying large groups of peanut allergic patients who are challenged with peanut ingestion in increasing amounts. From these, an eliciting dose that provokes a reaction in 10% of the food-allergic population has been estimated at between six and 14mg of peanut protein.

Translation of population eliciting doses (ED) into acceptable levels of allergen contamination for the population requires consideration of a 'safety factor'- to account for individual variability in dose threshold and severity. Data suggest such variability depends in part on extrinsic factors (exercise and sleep restriction). Each factor may have a different effect in scale and direction. The investigators are proposing a cross-over trial with 85 peanut-allergic adults who will each undergoing a baseline peanut challenge followed by repeat challenges with extrinsic factors applied, in random order (repeat baseline, +exercise and +sleep restriction). These data will further define ED for the UK population and a safety factor derived from shift in threshold, to inform industry and protect the allergic population.


Condition Intervention Phase
Peanut Hypersensitivity Other: Food challenge Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Official Title: The Effect of Extrinsic Factors on Food Allergy

Resource links provided by NLM:


Further study details as provided by Dr. Andrew Clark, Cambridge University Hospitals NHS Foundation Trust:

Primary Outcome Measures:
  • minimum amount of peanut protein in milligrams which causes an objective clinical reaction during peanut challenges [ Time Frame: 36 months ]

Estimated Enrollment: 100
Study Start Date: October 2012
Estimated Study Completion Date: October 2015
Estimated Primary Completion Date: September 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Arm 1
Exercise followed by sleep restriction followed by control challenge
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges
Experimental: Arm 2
Sleep restriction followed by exercise followed by control challenge
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges
Experimental: Arm 3
control followed by sleep restriction followed by exercise
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges
Experimental: Arm 4
control followed by exercise followed by sleep restriction
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges
Experimental: Arm 5
Sleep Restriction followed by control followed by exercise
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges
Experimental: Arm 6
Exercise followed by control followed by sleep restriction
Other: Food challenge
Double blind placebo controlled peanut challenge. Each challenge given with or without extrinsic factors exercise or sleep restriction.
Other Name: Threshold extrinsic factor challenges

  Show Detailed Description

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Written informed consent must be obtained before any assessment is performed.
  • Male and female subject who are 18-45 years of age at the time of study entry (Visit 1) who have a diagnosis of acute peanut allergy as manifested by urticaria, angioedema or respiratory/gastrointestinal tract symptoms, with acute onset of symptoms after ingestion (up to 2h).
  • A positive peanut DBPCFC at baseline (Visit 1). This outcome is defined as the onset of objective allergic events after ingestion of peanut protein but not to the placebo. Eligibility to the DBPCFC requires fulfillment of all other eligibility criteria at visit 1.
  • Subjects must be able to comply with the study procedures.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01429896


Contacts
Contact: Andrew T Clark, MB BS MD +44 1223 762603 andrew.clark@addenbrookes.nhs.uk

Locations
United Kingdom
Addenbrooke's Hospital Recruiting
Cambridge, Cambs, United Kingdom, CB2 2QQ
Principal Investigator: Andrew T Clark, MB BS MD         
Imperial College Recruiting
London, United Kingdom, W2 1PG
Contact: Robert Boyle, MB BS PhD         
Sponsors and Collaborators
Cambridge University Hospitals NHS Foundation Trust
Imperial College London
University of Manchester
Investigators
Study Director: Andrew T Clark, MB BS MD Cambridge University Hospitals NHS Trust
  More Information

Publications:
Responsible Party: Dr. Andrew Clark, Associate Lecturer and Consultant in Paediatric Allergy, Cambridge University Hospitals NHS Foundation Trust
ClinicalTrials.gov Identifier: NCT01429896     History of Changes
Other Study ID Numbers: 01.31.09.2011
First Submitted: August 31, 2011
First Posted: September 7, 2011
Last Update Posted: January 14, 2015
Last Verified: January 2015

Keywords provided by Dr. Andrew Clark, Cambridge University Hospitals NHS Foundation Trust:
peanut allergy
food allergy
thresholds
anaphylaxis
food labelling
food challenges
peanut challenges

Additional relevant MeSH terms:
Hypersensitivity
Food Hypersensitivity
Peanut Hypersensitivity
Immune System Diseases
Hypersensitivity, Immediate