Mast cell-nerve interactions in children with functional dyspepsia

Area of Science:

• Pediatric Gastroenterology
• Immunology
• Neurogastroenterology

Background:

• Functional dyspepsia in children is often linked to food allergens.
• Atopy (allergic disposition) plays a significant role in food-triggered dyspepsia.
• Understanding the mechanisms of food-induced dyspepsia in children is crucial for effective management.

Purpose of the Study:

• To investigate eosinophil and mast cell distribution in the gastric antrum.
• To examine mast cell product interactions with gastric nerves.
• To assess changes in gastric antral muscle slow wave activity in children with functional dyspepsia, differentiating between atopic and non-atopic groups.

Main Methods:

• An open-label study involving gastric mucosal cow's milk challenge in children (ages 2-12) with functional dyspepsia.
• Simultaneous electrogastrography and gastroscopy were performed.
• Laser scanning fluorescence microscopy analyzed mast cell tryptase association with mucosal nerves before and after milk challenge.

Main Results:

• Atopic children showed increased eosinophils and mast cells in the gastric antrum, with rapid degranulation post-cow's milk challenge.
• Mast cells were closely associated with mucosal nerves, releasing tryptase that interacted with nerve receptors.
• Gastric antral slow wave activity became abnormal within 2 minutes of antigen challenge in atopic children, showing increased instability and altered myoelectrical activity.

Conclusions:

• Cow's milk exposure induces early neuroimmune interactions in the gastric mucosa of atopic children.
• These interactions rapidly disrupt gastric myoelectrical activity, contributing to dyspeptic symptoms.
• The findings underscore the role of neuroimmune pathways in atopy-related pediatric functional dyspepsia.