Neuroimmune signalling pathways in chronic rhinosinusitis with nasal polyps

Purpose of review To evaluate the role of neuroimmune signalling pathways in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). Recent findings The sinonasal mucosa is densely infiltrated by immune cells and neuronal structures that share an intimate spatial relationship within tissue compartments. Together, such neuroimmune units play a critical role in airway defence and homeostatic function. CRSwNP is primarily driven by a type 2 immune endotype in the majority of patients. So far, central and peripheral neuronal mechanisms that promote, regulate and enhance immune responses have not been investigated to any detail within this disease group. Neurogenic inflammation, mediated by neuropeptides such as substance P and calcitonin gene-related peptide (CGRP), has been shown to modulate immune responses. Emerging evidence now suggests a bidirectional communication between immune cells and neurons, with inflammatory cytokines directly activating sensory neurons and influencing their function alongside the nervous system directly modulating immune cells. Summary The complex interplay between epithelial cells, immune cells and neurons in CRSwNP presents both challenges and opportunities for therapeutic intervention. Understanding these neuroimmune interactions not only provides valuable insights into the pathogenesis of CRSwNP but also may open up new avenues for therapeutic strategies targeting both the inflammatory and neuronal components of the disease.