Unveiling inflammatory patterns in chronic rhinosinusitis and allergy: harnessing algorithmic approaches via mass cytometry

Chronic rhinosinusitis (CRS) is a persistent inflammation of the nasal and paranasal sinus mucosa distinguished by two primary phenotypes called CRS with nasal polyps (CRSwNP) and without (CRSsNP). It often intersects with other respiratory disorders, such as asthma and a syndrome called non-steroidal anti-inflammatory drugs (NSAIDs)-exacerbated respiratory disease (N-ERD). CRS frequently coexists with respiratory allergies too. This study delves into the phenotypic landscape of peripheral blood mononuclear cells (PBMCs) in CRS patients, additionally examining the influence of comorbid respiratory allergies in these parameters. Serum, nasal secretions, and PBMC samples were retrieved from cohorts of controls, CRSsNP, CRSwNP, and N-ERD (n=6/group), with half of the patients in each group having respiratory allergies. Cytokine levels were measured in nasal secretions and sera. Additionally, immune cell abundance and phenotypic features in PBMCs were analyzed via mass cytometry. N-ERD patients showed heightened type 2 nasal cytokine levels. There were increased activated naive B cell levels in CRSwNP and N-ERD while resting naive B cells were higher in CRSsNP. Th2a cell levels did not differ between CRS subtypes but were significantly elevated in allergic subjects. In CRSwNP and N-ERD patients, naive B cells had lower CXCR5 and CD49d expression, while NK cells displayed reduced CD56 levels. In conclusion, there are distinct immunological features in PBMCs of CRS phenotypes and allergy, characterized by elevated resting naive B cells in CRSsNP, increased activated naive B cells in CRSwNP and N-ERD, and higher Th2a cell levels in allergic subjects.