Chronic Rhinosinusitis: Does Allergy Play a Role?

ATP functions as a primary alarmin in allergen-induced type 2 immunity

Environmental allergens that interact with the airway epithelium can activate cellular stress pathways that lead to the release of danger signals known as alarmins. The mechanisms of alarmin release are distinct from damage-associated molecular patterns (DAMPs), which typically escape from cells after loss of plasma membrane integrity. Oxidative stress represents a form of allergen-induced cellular stress that stimulates oxidant-sensing mechanisms coupled to pathways, which facilitate alarmin mobilization and efflux across the plasma membrane. In this review, we highlight examples of alarmin release and discuss their roles in the initiation of type 2 immunity and allergic airway inflammation. In addition, we discuss the concept of alarmin amplification, where "primary" alarmins, which are directly released in response to a specific cellular stress, stimulate additional signaling pathways that lead to secretion of "secondary" alarmins that include proinflammatory cytokines, such as IL-33, as well as genomic and mitochondrial DNA that coordinate or amplify type 2 immunity. Accordingly, allergen-evoked cellular stress can elicit a hierarchy of alarmin signaling responses from the airway epithelium that trigger local innate immune reactions, impact adaptive immunity, and exacerbate diseases including asthma and other chronic inflammatory conditions that affect airway function.

Association between sleep-disordered breathing and self-reported sinusitis in adults in the United States: NHANES 2005-2006

OBJECTIVES

The association between sleep-disordered breathing (SDB) and sinusitis has been widely studied; however, research on SDB-related sleep problems and sinusitis are limited. This study aims to determine the relationship between SDB-related sleep problems, SDB symptom score, and sinusitis.

METHODS

After the screening, data were analyzed from 3414 individuals (≥20 years) from the 2005-2006 National Health and Nutrition Examination Survey questionnaire. Data on snoring, daytime sleepiness, obstructive sleep apnea (snorting, gasping, or cessation of breathing while sleeping), and sleep duration were analyzed. The SDB symptom score was determined based on a summary of the scores of the above four parameters. Pearson chi-square test and logistic regression analysis were used in statistical analyses.

RESULTS

After adjusting for confounders, self-reported sinusitis was strongly correlated with frequent apneas (OR: 1.950; 95% CI: 1.349-2.219), excessive daytime sleepiness (OR: 1.880; 95% CI: 1.504-2.349), and frequent snoring (OR: 1.481; 95% CI: 1.097-2.000). Compared to an SDB symptom score of 0, the higher the SDB symptom score, the higher the risk of self-reported sinusitis. For the subgroup analyses, this association was significant in females and across ethnic groups.

CONCLUSION

In the United States, SDB is significantly associated with self-reported sinusitis in adults. In addition, our study suggests that patients with SDB should be aware of the risk of developing sinusitis.

Deep learning radiomics-based preoperative prediction of recurrence in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is characterized by poor prognosis and propensity for recurrence even after surgery. Identification of those CRS patients with high risk of relapse preoperatively will contribute to personalized treatment recommendations. In this paper, we proposed a multi-task deep learning network for sinus segmentation and CRS recurrence prediction simultaneously to develop and validate a deep learning radiomics-based nomogram for preoperatively predicting recurrence in CRS patients who needed surgical treatment. 265 paranasal sinuses computed tomography (CT) images of CRS from two independent medical centers were analyzed to build and test models. The sinus segmentation model achieved good segmentation results. Furthermore, the nomogram combining a deep learning signature and clinical factors also showed excellent recurrence prediction ability for CRS. Our study not only facilitates a technique for sinus segmentation but also provides a noninvasive method for preoperatively predicting recurrence in patients with CRS.

MicroRNAs: Potential Biomarkers of Disease Severity in Chronic Rhinosinusitis with Nasal Polyps

Background and Objectives: Chronic rhinosinusitis with nasal polyps (CRwNP) has multiple clinical presentations, and predictors of successful treatment are correlated to different parameters. Differentially expressed microRNAs in nasal polyps emerge as possible facilitators of precise endotyping in this disease. We aimed to evaluate the correlation between the clinical parameters of CRSwNP and two different microRNAs. Materials and Methods: The expression of miR-125b and miR-203a-3p in nasal polyps (n = 86) and normal nasal mucosa (n = 20) was determined through microarray analysis. Preoperative workup included CT scan, nasal endoscopy, blood tests, symptoms and depression questionnaires. Results: MiR-125b showed significant overexpression in NP compared to the normal nasal mucosa. miR-125b expression levels were positively and significantly correlated with blood eosinophilia (p = 0.018) and nasal endoscopy score (p = 0.021). Although high CT scores were related to miR-125b overexpression, the correlation did not reach statistical significance. miR-203a-3p was underexpressed in nasal polyps and was significantly underexpressed in CRSwNP patients with environmental allergies. Conclusions: Both miR-125b and miR-203a-3p are potential biomarkers in CRSwNP. miR-125b also correlates with the clinical picture, while miR-203a-3p could help identify an associated allergy.

Analysis of Bacterial Biofilm Formation and MUC5AC and MUC5B Expression in Chronic Rhinosinusitis Patients

Chronic rhinosinusitis (CRS) is a condition affecting as much as 16% of the adult population in developed countries with many factors attributed to its development, including the more recently proposed role of bacterial biofilm infections. Plenty of research has been conducted on biofilms in CRS and the causes behind the development of such an infection in the nasal cavity and sinuses. One such probable cause is the production of mucin glycoproteins by the mucosa of the nasal cavity. To investigate the possible link between biofilm formation and mucin expression levels and their relationship with CRS etiology, we examined samples from 85 patients by means of spinning disk confocal microscopy (SDCM) to establish their biofilm status and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine MUC5AC and MUC5B expression levels. We observed a significantly higher prevalence of bacterial biofilms in the CRS patient group compared to the control group. In addition, we detected higher expression levels of MUC5B but not MUC5AC in the CRS group, which suggested a possible role for MUC5B in CRS development. Finally, we found no direct relationship between biofilm presence and mucin expression levels, thereby showing a multifaceted connection between these two major factors implicated in CRS etiology.

The Role of Extracellular Vesicles in Diseases of the Ear, Nose, and Throat

Extracellular vesicles (EVs) are membranous nanoparticles produced by most cell types into the extracellular space and play an important role in cell-to-cell communication. Historically, EVs were categorized based on their methods of biogenesis and size into three groups: exosomes, microvesicles, and apoptotic bodies. Most recently, EV nomenclature has evolved to categorize these nanoparticles based on their size, surface markers, and/or the cell type which secreted them. Many techniques have been adopted in recent years which leverage these characteristics to isolate them from cell culture media and biological fluids. EVs carry various "cargo", including DNA, RNA, proteins, and small signaling molecules. After isolation, EVs can be characterized by various methods to analyze their unique cargo profiles which define their role in cell-to-cell communication, normal physiology, and disease progression. The study of EV cargo has become more common recently as we continue to delineate their role in various human diseases. Further understanding these mechanisms may allow for the future use of EVs as novel biomarkers and therapeutic targets in diseases. Furthermore, their unique cargo delivery mechanisms may one day be exploited to selectively deliver therapeutic agents and drugs. Despite the growing research interest in EVs, limited studies have focused on the role of EVs in the diseases of the ear, nose, and throat. In this review, we will introduce EVs and their cargo, discuss methods of isolation and characterization, and summarize the most up-to-date literature thus far into the role of EVs in diseases of the ear, nose, and throat.

Epithelial-Mesenchymal Transition in Atopy: A Mini-Review

Atopic diseases, particularly atopic dermatitis (AD), asthma, and allergic rhinitis (AR) share a common pathogenesis of inflammation and barrier dysfunction. Epithelial to mesenchymal transition (EMT) is a process where epithelial cells take on a migratory mesenchymal phenotype and is essential for normal tissue repair and signal through multiple inflammatory pathways. However, while links between EMT and both asthma and AR have been demonstrated, as we outline in this mini-review, the literature investigating AD and EMT is far less well-elucidated. Furthermore, current studies on EMT and atopy are mostly animal models or ex vivo studies on cell cultures or tissue biopsies. The literature covered in this mini-review on EMT-related barrier dysfunction as a contributor to AD as well as the related (perhaps resultant) atopic diseases indicates a potential for therapeutic targeting and carry treatment implications for topical steroid use and environmental exposure assessments. Further research, particularly in vivo studies, may greatly advance the field and translate into benefit for patients and families.

The Clinical and Radiological Characterizations of the Allergic Phenotype of Chronic Rhinosinusitis with Nasal Polyps

Purpose

The allergic phenotype of chronic rhinosinusitis (CRS) and central compartment atopic disease (CCAD) have been described. The CCAD is a radiological phenotype in patients with CRS that presents as a central mucosal disease due to allergy. The subset of patients having chronic rhinosinusitis with nasal polyps (CRSwNP) has not been well characterized. We aim to describe the clinical and radiological characterizations of patients presenting with the allergic phenotype of CRSwNP.

Patients and Methods

A cross-sectional study at a tertiary hospital was performed. Adult patients diagnosed with CRSwNP who had both allergology and radiological assessments were enrolled. The symptoms of allergic rhinitis, Lund-Kennedy (LK) endoscopic scoring, Lund-Mackay (LM) computed tomography scan of paranasal sinuses (CTPNS) scoring, CCAD features, skin prick test (SPT) and level of specific IgE were assessed. All the patients underwent SPT for house dust mites.

Results

A total of 38 patients were enrolled. Symptoms, endoscopic and CTPNS scores were higher in the allergy and CCAD groups compared to the nonallergy and nonCCAD groups. The symptom of "need to blow nose" was statistically significant in allergy vs nonallergy (p=0.01) and CCAD vs nonCCAD (p=0.02). There were significant differences in the endoscopic scores in both allergy and CCAD (allergy vs nonallergy, p=0.01; CCAD vs nonCCAD, p=0.03), and CT scores in both allergy and CCAD (allergy vs nonallergy, p=0.02; CCAD vs nonCCAD, p=0.02). All patients with CCAD have worse scoring than nonCCAD (LK score, p=0.03; LM score, p=0.02). Patients with allergy have more polypoidal involvement of the middle turbinates (left middle turbinate, p=0.141; right middle turbinate, p=0.074) and CCAD (left middle turbinate, p=0.017; right middle turbinate, p=0.009) than nonallergy and nonCCAD patients.

Conclusion

Allergic phenotype of CRSwNP has a worse clinical and radiological disease burden. Optimal treatment of allergy is essential for a better outcome.

Chronic Rhinosinusitis and Allergy: Increased Allergen Sensitization Versus Real Allergic Rhinitis Multimorbidity: a Systematic Review

PURPOSE OF REVIEW

The objective of this article is to provide a recent update of the association between allergic inflammation and chronic rhinosinusitis. The systematic approach of this review article critically evaluates the literature published over the past few years and summarizes the specific pathophysiologic pathway of chronic sinonasal inflammation that has been postulated.

RECENT FINDINGS

From a systematic search of the Ovid Medline and Embase, 11 studies were included in a qualitative analysis of the association between systemic allergy and chronic rhinosinusitis (CRS). Of the 11 studies, four showed an association, three were inconclusive, and four did not show any association. From the systematic search, 50 studies suggested four possible pathophysiologic pathways that may explain the association of allergic inflammation and CRS, namely, (1) staphylococcal enterotoxin, (2) the innate immunity pathway, (3) mast cell-associated inflammation, and (4) dysbiosis of microbiota. The association of systematic allergy and CRS remains inconclusive. The recent advances in the study of the pathophysiologic pathway of CRS may lead to the possibility of a targeted treatment option for CRS.

Central compartment atopic disease: prevalence of allergy and asthma compared with other subtypes of chronic rhinosinusitis with nasal polyps

BACKGROUND

Central compartment atopic disease (CCAD) is a recently described variant of chronic rhinosinusitis with nasal polyp (CRSwNP) associated with inhalant allergy. An association with asthma was noted to be uncommon within our clinical practice. The purpose of this study was to determine allergy and asthma prevalence in CCAD and other CRSwNP subtypes.

METHODS

A retrospective analysis at a tertiary care institution was performed over the period from 2015 to 2019. CRSwNP was grouped into the following subtypes: allergic fungal rhinosinusitis (AFRS); aspirin-exacerbated respiratory disease (AERD); CCAD; and CRSwNP not otherwise specified (CRSwNP NOS). Patients with sinonasal polyps and concomitant polypoid disease in the central compartment (CRSwNP/CC) were analyzed as a separate cohort for the purpose of this study. Prevalence of allergy and asthma was compared between groups.

RESULTS

Three hundred fifty-six patients were included. CRSwNP NOS was the most common subtype (37.1%) and CRSwNP/CC was the least common (3.7%), with other CRS subtypes ranging between 11.5% and 24.2%. Asthma prevalence was highest in AERD (100%) and CRSwNP NOS (37.1%), but substantially lower in AFRS (19.0%) and CCAD (17.1%). Asthma was significantly more common in AERD and CRSwNP NOS when compared with CCAD (p < 0.001 and p = 0.039, respectively). Prevalence of allergy was significantly higher in AFRS (100%), CCAD (97.6%), CRSwNP/CC (84.6%), and AERD (82.6%) when compared with CRSwNP NOS (56.1%) (p < 0.001).

CONCLUSION

CCAD represents a clinically distinct phenotype of CRSwNP with a high prevalence of allergy and low prevalence of asthma. Patients with both CCAD and diffuse sinonasal polyps had an allergy prevalence approaching that of CCAD and an asthma prevalence approaching CRSwNP NOS.