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

Study Description:

Eligible participants will be enrolled to assess the performance and accuracy of the 1-hour esophageal string test (EST) as a diagnostic screening tool for eosinophilic esophagitis (EoE). Consenting participants in the U.S. (n=30) and Mali (n=30) undergoing clinically indicated esophagogastroduodenoscopy (EGD) will have an EST performed prior to the procedure. Clinical data, including medical history and laboratory test results, will be captured on a case report form. Symptoms will also be assessed using validated patient reporting outcome measures: the Brief Esophageal Dysphagia Questionnaire (BEDQ) and Patient-Reported Outcomes Measurement Information System (PROMIS-GI and -57). Dietary, sociodemographic, and environmental histories will be obtained by validated questionnaires. Blood, urine, stool, and skin swab/tape strip samples will be obtained for additional biomarker studies.

Participants will be screened for intestinal helminth infections by stool polymerase chain reaction (PCR). Tissue samples obtained during EGD will be assessed for Helicobacter pylori by histopathology. Esophageal biopsy samples and remaining EST eluents will be allocated for investigational studies. Air and water samples will be collected from areas within the participants community and analyzed to determine potential correlation with elevated levels of environmental pollutants. The hypothesis of this study is that the 1-hour EST will provide a preliminary estimate of EoE prevalence among Africans and African immigrants presenting with dysphagia.

Primary Objective:

-Assess the accuracy of the 1-hour EST as a diagnostic screening tool for EoE among African individuals presenting with dysphagia in the U.S. and Mali.

Secondary Objective:

-Determine the frequency of EoE among African individuals presenting with dysphagia in the U.S. and Mali.

Primary Endpoint(s):

• Sensitivity, as estimated by the proportion of positive EST-obtained EoE-Score(TM) results out of those diagnosed with EoE by the gold standard of esophageal biopsy.
• Specificity, as estimated by the proportion of negative EST-obtained EoE-Score(TM) results out of those diagnosed with EoE by the gold standard of esophageal biopsy.

Secondary Endpoints:

-Proportion of EoE cases diagnosed in each cohort.

• INCLUSION CRITERIA:

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

• Able to provide informed consent.
• Aged 18 to 65 years.
• Born in the African continent or their parents were born in Africa,
• Exhibiting symptoms of dysphagia and/or prior history of food impaction.
• 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:

• Recent steroid use (systemic or swallowed/topical corticosteroid) within 4 weeks prior to endoscopy.
• Recent use of dupilumab (Dupixent) within the last 6 months.
• 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

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

• Current use of anticoagulant medications.

• Pregnancy.

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

• 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

• 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.