The relationship between lung function and the clinical and histopathological features in Chinese patients with nasal polyps

Risk Factors for Abnormal Small Airway Function Indicators in Nasal Polyp Patients with and without Asthma

INTRODUCTION

Small airway dysfunction (SAD) is associated with type 2 inflammation in patients who have non-asthmatic chronic rhinosinusitis with nasal polyps (CRSwNPs); however, the risk factors for abnormal small airway function indicators in CRSwNP patients with and without asthma remain unclear.

METHODS

We retrospectively analyzed 41 asthmatic and 109 non-asthmatic CRSwNP patients. Clinical characteristics were compared between groups, correlations between small airway function and clinical parameters were calculated, and independent risk factors for every small airway indicator were identified in each group.

RESULTS

Asthmatic CRSwNP patients had significantly reduced small airway function, and the proportion of patients with SAD was higher in asthmatic CRSwNP patients (65.85%) than in patients without asthma (9.17%). With regard to specific airway function indicators, age and a patient's blood eosinophil (%) were identified as independent risk factors for lower FEF50% %pred and FEF25-75% pred, with age being an independent risk factor for FEF75% %pred in asthmatic CRSwNP patients. In non-asthmatic CRSwNP patients, allergic rhinitis comorbidity was found to be an independent risk factor for FEF50% %pred, FEF75% %pred, and FEF25-75% %pred.

CONCLUSION

Physicians should pay greater attention to risk factors for abnormal small airway function indicators in patients with CRSwNPs to prevent the occurrence of SAD.

The roles of eosinophils and interleukin-5 in the pathophysiology of chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is generally associated with eosinophilic tissue infiltration linked to type 2 inflammation and characterized by elevated levels of interleukin (IL)-5 and other type 2 inflammatory mediators. Although distinct and overlapping contributions of eosinophils and IL-5 to CRSwNP pathology are still being explored, they are both known to play an important role in NP inflammation. Eosinophils secrete numerous type 2 inflammatory mediators including granule proteins, enzymes, cytokines, chemokines, growth factors, lipids, and oxidative products. IL-5 is critical for the differentiation, migration, activation, and survival of eosinophils but is also implicated in the biological functions of mast cells, basophils, innate lymphoid cells, B cells, and epithelial cells. Results from clinical trials of therapeutics that target type 2 inflammatory mediators (including but not limited to anti-IL-5, anti-immunoglobulin-E, and anti-IL-4/13) may provide further evidence of how eosinophils and IL-5 contribute to CRSwNP. Finally, the association between eosinophilia/elevated IL-5 and greater rates of NP recurrence after endoscopic sinus surgery (ESS) suggests that these mediators may have utility as biomarkers of NP recurrence in diagnosing and assessing the severity of CRSwNP. This review provides an overview of eosinophil and IL-5 biology and explores the literature regarding the role of these mediators in CRSwNP pathogenesis and NP recurrence following ESS. Based on current published evidence, we suggest that although eosinophils play a key role in CRSwNP pathophysiology, IL-5, a cytokine that activates these cells, also represents a pertinent and effective treatment target in patients with CRSwNP.

Th17/1-Biased Inflammatory Environment Involved in the Response of Epithelial Cells to Antigen Stimuli in Nasal Polyps

Several studies showed that IL-17A was significantly increased in nasal polyps (NPs). However, the source and characteristics of IL-17A-producing cells in NPs were not fully understood. We isolated mononuclear cells from NPs and uncinate tissues and analyzed them using flow cytometry. The results indicated that IL-17A was increased in NP tissues compared to uncinate tissues. The main IL-17A-expressing cells were CD3⁺ T cells in NP tissues, including Th17 cells, Tc17 cells, and γδT17 cells. Not similar to those in uncinate tissues, the majority of Th17 cells highly coexpressed IFN-γ in NP tissues, such as Th17/1 cells, which highly expressed CXCR3, CCR6, RORγt, and T-bet. Furthermore, Th17/1-biased environment increased the response of nasal epithelial cells to bacterial and viral stimuli, implying that Th17/1 cells play a greater role in the pathological development of NPs than Th17 or Th1 cells.