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

Overview

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.

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.