Understanding the genetics and natural history of food allergies and related conditions

Natural History and Genetics of Food Allergy and Related Conditions

This study is trying to understand the causes of food allergies and related conditions by looking at the genetics and health history of people with food allergies, their families, and healthy volunteers over several years.

Quick facts

• Study type: Observational
• Enrollment: 1800 (estimated)
• Ages: 1 Day to 99 Years
• Sex: All
• Sponsor: National Institutes of Health Clinical Center (CC) (NIH)
• Locations: 1 site (Bethesda, Maryland)
• Trial ID: NCT02504853 on ClinicalTrials.gov

What this trial studies

This observational study aims to investigate the causes and effects of food allergies and related conditions such as Loeys-Dietz Syndrome, Atopic Dermatitis, and Eosinophilic Esophagitis. Participants aged 2 to 99, including those with food allergies, their relatives, and healthy volunteers, will undergo a series of evaluations over 1 to 12 years, including medical history assessments, physical exams, and various tests like blood tests and allergy skin prick tests. The study seeks to identify genetic, cellular, and immunologic factors contributing to food allergies and to discover biomarkers that may predict clinical outcomes.

Who should consider this trial

Good fit: Ideal candidates include individuals aged 2 to 99 with a clinical history of food allergies or related conditions, as well as their relatives.

Not a fit: Patients without food allergies or related conditions, or those who do not meet the age criteria, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to a better understanding of food allergies, potentially informing future treatments and prevention strategies.

How similar studies have performed: Other studies have shown success in understanding the genetic and environmental factors of food allergies, making this approach both relevant and promising.

Eligibility criteria

* GENERAL INCLUSION CRITERIA:

All participants must meet the following criteria:

1. Be 2 to 99 years-old at the time of enrollment for participants who will be seen at the NIH CC; be 0 (newborn) to 99 years-old at the time of enrollment for participants who will submit mail-in samples or participate in telehealth visits. Only viable neonates will be enrolled.
2. Willing to allow storage of blood, buccal swabs, saliva, nasal swabs, stool samples, and other clinically appropriate tissue specimens for future use in medical research
3. Required to have a primary care or other physician who will manage all health conditions related or unrelated to the study objectives

ADDITIONAL INCLUSION CRITERIA FOR AFFECTED PARTICIPANTS

In addition to the general criteria listed above, affected participants must meet 1 of the following criteria:

1. Have a clinical history of an immediate hypersensitivity reaction to food(s) and be sensitized to food allergen(s) (as evidenced by positive SPT or allergen-specific IgE testing)
2. Be sensitized (as evidenced by positive SPT or allergen-specific IgE testing) to food allergen(s) but have no overt clinical history of IgE-mediated symptoms when they eat that food(s)
3. Have a suspected genetic or congenital disorder potentially associated with food allergy or related condition, as determined by the principal investigator (PI) or associate investigators (AIs)
4. Have a diagnosis of eosinophilic esophagitis (EoE), or clinical suspicion for EoE as determined by the principal investigator (PI) or associate investigators (AIs)
5. Have a history of atopic dermatitis based on self-report or physician assessment.

ADDITIONAL INCLUSION CRITERIA FOR UNAFFECTED RELATIVES:

In addition to the general criteria listed above, unaffected relatives must meet the following criteria:

1. Be a relative of an affected participant
2. Be unaffected by food allergy (as determined by clinical history and/or allergy testing) or be unaffected by the genetic condition under study

ADDITIONAL INCLUSION CRITERIA FOR HEALTHY VOLUNTEERS

In addition to the general criteria listed above , healthy volunteers must meet the following criteria:

1. Be unrelated to an affected participant
2. Be unaffected by food allergy (as determined by clinical history and/or allergy testing) or be unaffected by the genetic condition under study

ADDITIONAL PROCEDURE- SPECIFIC INCLUSION CRITERIA:

The following additional inclusion criteria apply for participants undergoing leukapheresis:

1. Age greater than or equal to 18 years
2. Stable hematologic parameters (definition: white blood cell count \> 2,500/microL, hemoglobin \> 10 g/dL, and platelet count \> 75,000/microL)

GENERAL EXCLUSION CRITERIA:

Participants will be excluded for any of the following:

* Presence of conditions that, in the judgment of the investigator or the referring physician, may put the participant at undue risk or make them unsuitable for participation in the study.
* Inability to participate for the duration of the study.
* The PI deems that participation in the study would not be expected to advance the study goals.

ADDITIONAL PROCEDURE- SPECIFIC EXCLUSION CRITERIA

Additional exclusion criteria apply for unaffected relatives and healthy volunteers who are undergoing endoscopy with biopsies for research purposes. Unaffected relatives and healthy volunteers will be excluded from participating in this procedure if they meet any of the following criteria:

1. uncontrolled asthma or Grade 3 or higher by the American Society of Anesthesiologist s. Physical Status Classification System (http://www.asahq.org/resources/clinicalinformation/.asa-physical-status-classification-system)
2. history of adverse reaction to conscious sedation or general anesthesia required for endoscopy
3. hemoglobin \< 11 g/dL
4. platelet count \< 100,000 microL
5. PT INR \>1.3 or PTT prolonged by \> 3 seconds
6. pregnant or breastfeeding
7. viral screens positive for HIV or hepatitis B or C
8. severe unstable myocardial ischemia or cardiomyopathy
9. severe hypoxemia due to chronic pulmonary disease
10. recent abdominal surgery
11. anticoagulant therapy that cannot be interrupted
12. history of reflux disease within the last 3 years or use of acid-suppression medication (including over-the-counter medications such as Tums, Rolaids, Zantac, Prilosec OTC, or Prevacid OTC) within the last 2 months
13. chronic GI or immunologic disease
14. clinically indicated EGD or colonoscopy within the past 12 months
15. use of systemic or inhaled corticosteroids within the past 4 months
16. have a history of EGID including EoE
17. younger than 18 years of age

Where this trial is running

Bethesda, Maryland

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States (Recruiting)

Study contacts

• Principal investigator: Pamela A Guerrerio, M.D. — National Institute of Allergy and Infectious Diseases (NIAID)
• Study coordinator: Ellen Zektser, R.N.

Conditions Food Allergy; Loeys-Dietz Syndrome; Atopic Dermatitis; Eosinophilic Esophagitis; TGFbeta; Natural History