Distinct inflammatory features and nasal TH2 cell profiles in allergic patients with chronic rhinosinusitis

BACKGROUND: Various factors affect the immunopathogenesis of chronic rhinosinusitis (CRS). Although the relationship between allergies and CRS has attracted considerable attention, it remains controversial. Notably, little is known about whether the clinical characteristics and immunological profiles differ based on allergic sensitization status among patients with CRS. METHODOLOGY: This study included 209 patients with CRS with nasal polyps (CRSwNP) who underwent endoscopic sinus surgery, and their nasal polyp tissues were obtained. Patients were divided into two groups according to allergic sensitization status: "allergic" and "non-allergic" groups. The clinical characteristics and immunological profiles were compared between the two groups. Ex vivo phenotypes of nasal CD4+ T cells were analyzed using flow cytometry. RESULTS: Compared to the non-allergic group, the allergic group exhibited a significantly higher prevalence of comorbid asthma, serum total IgE levels, SNOT-22 scores, JESREC scores, blood/ tissue eosinophil counts, the proportion of eosinophilic histologic type, and lower gustatory function test scores. Additionally, the frequencies of nasal T helper 2 (TH2) and proallergic TH2 (TH2A) cells were significantly higher in the allergic group than in both the non-allergic and the control groups, and these frequencies were significantly correlated with eosinophilic inflammation. CONCLUSIONS: Our study demonstrates that allergic sensitization is closely associated with eosinophilic inflammation, as indicated by elevated levels of blood/tissue eosinophils and nasal TH2A cells, and by worse symptom scores in CRSwNP. Given the distinct immunological features of allergic patients, considering allergic sensitization within nasal tissue when managing CRSwNP is crucial.