Eosinophil progenitor level as a biomarker for disease activity in eosinophilic esophagitis
Marc Rothenberg, MD, PhD
BACKGROUND: Eosinophilic esophagitis (EoE) is a chronic, food antigen–driven gastrointestinal disease, characterized by marked esophageal eosinophilia that results in severe feeding difficulties and pain. After a change in therapy, EoE disease activity is determined via invasive serial endoscopies with esophageal biopsies. GAP: There is a compelling need to develop novel, less-invasive biomarkers to evaluate EoE disease activity to reduce the risks and the significant expense associated with repeat endoscopy for patients with EoE. HYPOTHESIS: We hypothesize that peripheral blood eosinophil progenitors (EoPs) are in greater numbers in patients with active EoE than inactive EoE and that active atopic disease will not affect the EoP threshold that accurately identifies individuals with active EoE. METHODS: In a prospective observational study, we will determine the association of peripheral blood EoP counts with established measurements of EoE disease activity in individuals with EoE and establish a cutoff EoP level that will accurately identify patients with active EoE disease. We will also determine the effect of active atopic disease on the false-positive rate for the cutoff EoP level that accurately identifies patients with active EoE disease. RESULTS: Pending IMPACT: We envision using the blood EoP level as a clinical test to monitor EoE disease activity to assist providers in determining response to treatment and potentially eliminating the need for repeated endoscopies. Development of such a marker has the potential to change the treatment paradigm in this disease, as one of the considerations limiting a family’s interest in and access to dietary therapy is the need for repeated endoscopy to assess response to dietary manipulation.