The Esophageal String Test as a Diagnostic Screening Tool for Eosinophilic Esophagitis Among Africans With Dysphagia in Mali and the United States

What this study involves

The registry says this study is recruiting. Individual locations may have different availability.

Study type

Interventional

Phase

Not applicable

Age range

18 years - 65 years

Sex eligible

All sexes

Healthy volunteers

Not accepted

Participants

70 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

Background:

Eosinophilic esophagitis (EoE) is a disease that causes inflammation in the esophagus. The esophagus is the tube that moves food from the mouth to the stomach. Diagnosing EoE currently requires a specialized tool called an endoscope. The esophageal string test (EST) is another test; the EST collects fluid from the upper digestive tract. An EST is simpler and cheaper than an endoscopy. Researchers want to know if an EST can diagnose EoE.

Objective:

To test if the EST can diagnose EoE in people who have trouble swallowing.

Eligibility:

Adults aged 18 to 65 years with trouble swallowing. They must have been born in the African continent or their parents were born in Africa.

Design:

Participants will be screened. They will give blood, stool, urine, and skin swab samples. They will complete surveys about their medical history, diet, symptoms, and home environment. They will bring a sample of their drinking water for testing.

Participants will have an EST. They will swallow a pill capsule that contains a nylon string. One end of the string will be taped to their cheek. The string will unravel down the esophagus and into the stomach. It will be pulled out after 1 hour. Fluids that soaked into the string will be tested.

At a different visit, participants will have an endoscopic exam. An endoscope is a flexible tube that is inserted down the mouth; it can be used to take tissue samples from the esophagus, stomach, and small intestine.

Participants will have a final visit in person, online, or by phone. They will take a survey and talk about their test results.

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

• INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

1. Able to provide informed consent.
2. Aged 18 to 65 years.
3. Born in the African continent or their parents were born in Africa,
4. Exhibiting symptoms of dysphagia and/or prior history of food impaction.
5. Undergoing clinically indicated endoscopy at the NIH Clinical Center (U.S.), Centre Hospitalier Universitaire Gabriel Tour(SqrRoot)(Copyright) (Mali), or other local clinics (Mali) and willing to provide research samples and data.

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

1. Recent steroid use (systemic or swallowed/topical corticosteroid) within 4 weeks prior to endoscopy.
2. Recent use of dupilumab (Dupixent) within the last 6 months.
3. Recent use of other biologic medications (within either 6 months or 5 half-lives, whichever is longer). Examples of biologic medications include:

3a. mepolizumab (Nucala)

3b. reslizumab (Cinqair, Cinqaero)

3c. benralizumab (Fasenra)

3d. cendakimab

3e. tezepelumab (Tezspire)

3f. barzolvolimab

4\. Individuals suffering from a bleeding diathesis (e.g., hemophilia, severe thrombocytopenia).

5\. Current use of anticoagulant medications.

6\. Pregnancy.

7\. Treatment with another investigational drug or other investigational intervention within 6 months or 5 half-lives whichever is longer.

8\. Individuals with a known history of any of the following:

8a. eosinophilic esophagitis

8b. esophageal stricture unable to be passed with an upper endoscope

8c. esophageal cancer

8d. esophageal motility disorder (e.g., achalasia)

8e. esophageal varices

8f. esophageal or gastric surgery including fundoplication

8g. neurologic cause of dysphagia (e.g., stroke, Parkinson s disease, etc.)

8h. allergy to gelatin

8i. inability to swallow pills

9\. Any condition that, in the investigator s opinion, places the individual at undue risk by participating in the study.

Co-enrollment guidelines: Co-enrollment in other trials is restricted, other than enrollment on observational studies. Consideration for co-enrollment in trials evaluating the use of a licensed medication will require the approval of the principal investigator in consultation with the medical monitor. Study staff should be notified of co-enrollment on any other protocol as it may require the approval of the principal investigator.

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Not applicable

Masking

No masking

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (3)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

3 locations

Study team and timeline

Lead sponsor

National Institute of Allergy and Infectious Diseases (NIAID)

Study start

Nov 15, 2026 Estimated

Primary completion

Aug 31, 2027 Estimated

Study completion

Aug 31, 2027 Estimated

First posted

Jun 19, 2025 Actual

Last updated

Nov 10, 2026 Actual

Official study contacts