Mucosal Eosinophilia and Neutrophilia Are Not Associated With QOL or Olfactory Function in Chronic Rhinosinusitis

Background: Chronic rhinosinusitis (CRS) is often differentiated by histopathologic phenotypes (eosinophilic versus neutrophilic), which may impact disease severity measures and outcomes. As such, it has been suggested that counts of cellular elements be included as part of a standard pathological report following endoscopic sinus surgery (ESS). Objectives: This cross-sectional study evaluated associations of mucosal eosinophilia and neutrophilia with measures of quality-of-life (QoL) and olfactory function. Methods: Patients with medically refractory CRS completed the SNOT-22 survey and Brief Smell Identification Test (BSIT) at enrollment. In addition, baseline Lund-Mackay computed tomography (CT) and Lund-Kennedy endoscopy scores were collected. Ethmoid mucosa was biopsied during ESS and reviewed using microscopy to quantify densest infiltrate of eosinophils or neutrophils per high-powered-field (HPF). Eosinophilic CRS (eCRS) and neutrophilic CRS (nCRS), both with and without nasal polyposis (NP), were compared across SNOT-22 and BSIT scores. Results: 77/168 patients demonstrated mucosal eosinophilia (eCRS) while a total of 42/168 patients demonstrated mucosal neutrophilia (nCRS). After adjusting for polyp status, 35/168 had eCRSsNP, 42/168 eCRSwNP, 75/168 non-eCRSsNP, 16/168 non-eCRSwNP. Additionally, 22/161 were noted to have nCRSsNP, 20/161 nCRSwNP, 84/161 non-nCRSwNP, and 35/161 non-nCRSsNP. A small subset of patients demonstrated both eosinophilia and neutrophilia: 14 CRSwNP and 7 CRSsNP. When evaluating average Lund-Mackay Scores (LMS), significant differences existed between non-eCRSsNP and eCRSsNP (p = 0.006). However, after controlling for nasal polyps, eosinophilia did not significantly associate with differences in the Lund-Kennedy Score. Neutrophilia did not significantly associate with any changes in LMS or LKS after controlling for NP. Eosinophilic and neutrophilic histopathologic subtypes did not significantly associate with differences in baseline SNOT-22 or BSIT measures after controlling for NP. Conclusion: Neither the presence of mucosal eosinophilia nor mucosal neutrophilia demonstrated significant associations with SNOT-22 quality-of-life or BSIT olfactory function scores when controlling for comorbid nasal polyposis.