Major Basic Protein Deposition Without Eosinophilic Infiltration in Hypercontractile Esophagus: A Case Report

Area of Science:

• Gastroenterology
• Esophageal Motility Disorders
• Immunopathology

Background:

• Hypercontractile esophagus is a motility disorder with excessive esophageal contractions.
• Eosinophilic infiltration in the esophageal muscle layer is sometimes observed, but its clinical significance is unclear.

Purpose of the Study:

• To report a case of hypercontractile esophagus with potential eosinophilic inflammation detected by immunostaining, despite negative standard staining.
• To investigate the utility of eosinophil granule protein staining in identifying eosinophilic activity in esophageal muscle.

Main Methods:

• High-resolution manometry to diagnose hypercontractile esophagus (Chicago Classification v4.0).
• Esophagogastroduodenoscopy to assess esophageal peristalsis.
• Biopsies analyzed with hematoxylin and eosin (H&E) staining and immunofluorescence for major basic protein (MBP).

Main Results:

• A patient with dysphagia and hypercontractile esophagus showed no eosinophils on H&E staining.
• Immunofluorescence revealed patchy MBP depositions in the esophageal muscle layer.
• Evidence suggested MBP release via eosinophil cytolysis, indicating eosinophilic activity.

Conclusions:

• Immunostaining for MBP can reveal eosinophilic activity in the esophageal muscle layer, even when eosinophils are not apparent on H&E staining.
• MBP deposition may indicate a localized immune-mediated process contributing to hypercontractile esophagus.
• Further research is needed to understand the role of eosinophilic inflammation in esophageal motor disorders.