Endotype-Phenotype Correlation in Chronic Rhinosinusitis: Is It Time to Think Beyond Polyposis?

The correlation between periostin and eosinophillic cationic protein demonstrate its potential biomarker of mucosal remodeling in chronic rhinosinusitis with nasal polyps

INTRODUCTION

Chronic rhinosinusitis (CRS) is classified into CRS with nasal polyps (CRSwNP), a type 2 inflammation with elevated CLC and ECP levels, and CRS without nasal polyps (CRSsNP), a non-type 2 inflammation. Periostin plays a crucial role in mucosal remodeling, but its involvement in CRSwNP remains unclear.

AIMS/OBJECTIVES

To investigate correlation between CRSwNP endotype and periostin levels.

MATERIALS AND METHODS

This cross-sectional study measured endotype biomarkers (ECP, CLC, IFN-γ, IL-17A) and periostin levels in uncinate process and nasal polyps using ELISA to assess their correlation.

RESULTS

99.6% of uncinate process and 36.67% of nasal polyp tissue samples displayed a mixed endotype pattern, while 2 samples were untype-able. Periostin levels were significantly higher in nasal polyp compared to uncinate process tissue (p = .0116) and control. Only ECP levels in the uncinate process showed a significant correlation with periostin (r = 0.326, p = .038).

CONCLUSION AND SIGNIFICANCE

Periostin is significantly elevated in nasal polyps, highlighting its role in CRSwNP. Its correlation with ECP in the uncinate process suggests involvement in inflammation, warranting further research into periostin as a therapeutic target. This study confirms periostin's role in CRSwNP, it potentially occurs with or without depending on the CRS endotype pathways.

Incidence Rates and Risk Ratios of Normal Tension Glaucoma in Patients with Chronic Rhinosinusitis: A Population-Based Longitudinal Follow-Up Study

Several studies have investigated the association between chronic rhinosinusitis (CRS) and ophthalmological complications. However, it remains uncertain whether CRS is independently associated with the development of normal tension glaucoma (NTG). Therefore, this retrospective cohort study aimed to investigate the prospective association between CRS and the increased incidence and risk of NTG using a representative population-based dataset. The selection of both the CRS and comparison groups was meticulously conducted through the propensity scoring method. The incidence and risk ratios of NTG were measured using person-years at risk and a weighted Cox proportional hazards model. We enrolled 30,284 individuals without CRS (comparison group) and 15,142 individuals with CRS. The NTG incidence rates were 1.19 and 0.81 in the CRS and comparison groups, respectively. The CRS group showed a significantly increased risk of subsequent development for NTG (adjusted hazard ratio = 1.41, 95% confidence interval = 1.16-1.72), regardless of the CRS subtype. Additionally, the risk of developing NTG was relatively higher in the first 2 years after CRS diagnosis. Moreover, a subgroup analysis revealed a higher risk of NTG in elderly female individuals with CRS. The present findings underscore the importance of monitoring and managing NTG risk in individuals with CRS, especially in elderly female patients.

A Decade of Pathogenesis Advances in Non-Type 2 Inflammatory Endotypes in Chronic Rhinosinusitis: 2012-2022

Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by localized inflammation of the upper airways. CRS includes two main phenotypes, namely, CRS with nasal polyps and CRS without nasal polyps. The phenotype-based classification method cannot reflect the pathological mechanism. The endotype-based classification method has been paid more and more attention by researchers. It is mainly divided into type 2 and non-type 2 endotypes. The mechanism driving the pathogenesis of non-type 2 inflammation is currently unknown. In this review, the PubMed and Web of Science databases were searched to conduct a critical analysis of representative literature works on the pathogenesis of non-type 2 inflammation in CRS published in the past decade. This review summarizes the latest evidence that may lead to the pathogenesis of non-type 2 inflammation. It is the main method that analyzing the pathogenesis from the perspective of immunology. Genomics and proteomics technique provide new approaches to the study of the pathogenesis. Due to differences in race, environment, geography, and living habits, there are differences in the occurrence of non-type 2 inflammation, which increase the difficulty of understanding the pathogenesis of non-type 2 inflammation in CRS. Studies have confirmed that non-type 2 endotype is more common in Asian patients. The emergence of overlap and unclassified endotypes has promoted the study of heterogeneity in CRS. In addition, as the source of inflammatory cells and the initiation site of the inflammatory response, microvessels and microlymphatic vessels in the nasal mucosal subepithelial tissue participate in the inflammatory response and tissue remodeling. It is uncertain whether CRS patients affect the risk of infection with SARS-CoV-2. In addition, the pathophysiological mechanism of non-type 2 CRS combined with COVID-19 remains to be further studied, and it is worth considering how to select the befitting biologics for CRS patients with non-type 2 inflammation.

Sweet taste receptor agonists attenuate macrophage IL-1β expression and eosinophilic inflammation linked to autophagy deficiency in myeloid cells

BACKGROUND

Eosinophilic inflammation is a hallmark of refractory chronic rhinosinusitis (CRS) and considered a major therapeutic target. Autophagy deficiency in myeloid cells plays a causal role in eosinophilic CRS (ECRS) via macrophage IL-1β overproduction, thereby suggesting autophagy regulation as a potential therapeutic modality. Trehalose is a disaccharide sugar with known pro-autophagy activity and effective in alleviating diverse inflammatory diseases. We sought to investigate the therapeutic potential of autophagy-enhancing agent, trehalose, or related sugar compounds, and the underlying mechanism focusing on macrophage IL-1β production in ECRS pathogenesis.

METHODS

We investigated the therapeutic effects of trehalose and saccharin on macrophage IL-1β production and eosinophilia in the mouse model of ECRS with myeloid cell-specific autophagy-related gene 7 (Atg7) deletion. The mechanisms underlying their anti-inflammatory effects were assessed using specific inhibitor, genetic knockdown or knockout, and overexpression of cognate receptors.

RESULTS

Unexpectedly, trehalose significantly attenuated eosinophilia and disease pathogenesis in ECRS mice caused by autophagy deficiency in myeloid cells. This autophagy-independent effect was associated with reduced macrophage IL-1β expression. Various sugars recapitulated the anti-inflammatory effect of trehalose, and saccharin was particularly effective amongst other sugars. The mechanistic study revealed an involvement of sweet taste receptor (STR), especially T1R3, in alleviating macrophage IL-1β production and eosinophilia in CRS, which was supported by genetic depletion of T1R3 or overexpression of T1R2/T1R3 in macrophages and treatment with the T1R3 antagonist gurmarin.

CONCLUSION

Our results revealed a previously unappreciated anti-inflammatory effect of STR agonists, particularly trehalose and saccharin, and may provide an alternative strategy to autophagy modulation in the ECRS treatment.