Role of Esophageal Mast Cell Activation in Noncardiac Chest Pain (NCCP)

1. Key Objectives: To determine the density and activation of esophageal mast cells in non-cardiac chest pain patients. We expect to find mast cell activation, as measured by mast cell count or degranluation, tryptase staining, and histamine release, will be greater in NCCP patients compared to controls, and the increased mast cell activation will correlate with the severity of NCCP. These results will expand our understanding of the pathogenesis of esophageal originated NCCP, and allow the development of new diagnostic and treatment options. 2. Study Population: (i) NCCP (ii) Reflux esophagitis (iii) Control subjects. 3. Summary of Procedures: (i) symptom assessment by chest pain questionnaire; (ii) esophageal reflux evaluation by review of records of 24-hour pH monitoring; (iii) evidence of esophagitis by endoscopy; (iv) esophageal biopsy by endoscopy; (v) mast cell activation study in biopsy specimen by mast cell count, tryptase and Transient receptor potential vanniloid-1 (TRPV1) staining, and histamine release assay. 4. Major Risks \& Discomforts: There are no major risks \& discomforts other than involved in standard upper GI endoscopy.