Bartemes, Kathleen R

ABSTRACT Introduction Changes in peripheral eosinophils follow endoscopic sinus surgery (ESS) in chronic rhinosinusitis with nasal polyps (CRSwNP), with and without aspirin sensitivity. Cytometry by time‐of‐flight (CyTOF) identifies more immune cell subsets than conventional assays or clinical testing. We hypothesized that ESS‐associated changes in peripheral immune cell subsets differ between aspirin‐tolerant (AT)‐CRSwNP and aspirin‐exacerbated respiratory disease (AERD) as measured by CyTOF. Methods Pre‐ and post‐ESS peripheral blood from patients with CRSwNP ( n = 13) or with AERD ( n = 15) was analyzed for immune cell populations using a 37‐marker CyTOF panel. CITRUS analysis identified cell clusters most predictive of patient group or sample timepoint. Results In the combined cohort of 28 patients, circulating CD4 + naïve T cells and CD194 + neutrophils increased after ESS, while eosinophils decreased. When stratified by disease, CD4 + naïve T cells increased in both AERD and CRSwNP post‐ESS; however, eosinophils decreased after ESS only in CRSwNP. Neutrophil subsets showed a mixed response in both patient groups after ESS. Dendritic cells increased in CRSwNP but not in AERD after ESS. Individual timepoint analyses showed more CD141 + monocyte‐derived DCs (moDCs) in CRSwNP than in AERD pre‐ and post‐ESS. Pre‐ESS, both CD185 + and CD194 + neutrophils were higher in AERD compared to CRSwNP. Conclusion CD141 + moDCs were more prevalent in CRSwNP versus AERD, both before and after ESS. Naïve CD4 + T cells increased, and neutrophil subsets changed in all groups after ESS, but eosinophils decreased only in CRSwNP. Our study points to possible systemic immune effects of ESS and candidate immune signatures in CRSwNP and AERD.