Characterisation of MRGPRX2+ mast cells in irritable bowel syndrome
Background Mast cell activation is an important driver of abdominal pain in irritable bowel syndrome (IBS). While evidence supports the role of IgE-mediated mast cell activation in visceral pain development in IBS, the role of pseudoallergic MRGPRX2-mediated mast cell activation in this process remains unknown. Objective We investigated whether MRGPRX2-mediated mast cell activation plays a role in abdominal pain development in patients with IBS. Design MRGPRX2 expression in mast cells and other immune cells was characterised across colon layers using flow cytometry. We evaluated whether MRGPRX2 agonists trigger mast cell degranulation and transient receptor potential vanilloid 1 (TRPV1) sensitisation in healthy human colonic submucosal plexus samples using live imaging. Rectal biopsies were then collected from patients with IBS and healthy volunteers (HV) and MRGPRX2+ mast cell frequency, MRGPRX2 expression per cell, mast cell degranulation kinetics in response to MRGPRX2 agonists, MRG
