The Underestimated Role of Mast Cells in the Pathogenesis of Rhinopathies.

Mast cells (MCs) are involved in several biological processes, such as defense against pathogens, immunomodulation, tissue repair after injury, and angiogenesis. MCs have been shown to change from protective immune cells to potent pro-inflammatory cells, influencing the progression of many pathological conditions, including autoimmune diseases and cancers. The role of MCs in the pathogenesis of rhinopathies has often been underestimated, since previous studies have focused their attention on eosinophils and neutrophils, while MCs were considered involved exclusively in allergic rhinitis. However, recent nasal cytology findings have shown the involvement of MCs in several rhinopathies, such as NARMA, NARESMA, and CRSwNP. These recent evidences highlight the crucial role that MCs play in orchestrating the inflammation of the nasal mucosa, through complex biological mechanisms, not yet fully understood. In this context, a better understanding of these mechanisms is fundamental for practicing Precision Medicine, which requires careful population selection and stratification into subgroups based on the phenotype/endotype of the patients, in order to guarantee the patient a tailored therapy. Based on this background, further studies are needed to understand the pathophysiological mechanisms involving MCs and, consequently, to develop targeted therapies aimed to obtain a selective inhibition of tissue remodeling and preventing MC-mediated immune suppression.