Prevalence and impact of nasal hyperreactivity in chronic rhinosinusitis

Rare presence and function of neuroendocrine cells in the nasal mucosa

There is growing evidence that neurogenic inflammation contributes to the pathophysiology of upper airway diseases, with nasal hyperreactivity (NHR) being a key symptom. The rare neuroendocrine cells (NECs) in the epithelium have been linked to the pathophysiology of bronchial and intestinal hyperreactivity, however their presence in the nasal mucosa and their potential role in NHR remains unclear. Therefore, we studied the presence of NECs in the nasal epithelium of controls, allergic rhinitis patients and chronic rhinosinusitis with nasal polyps patients, and their link to NHR. The expression of typical NECs markers, CHGA, ASCL1 and CGRP, were evaluated on gene and protein level in human samples using real-time quantitative PCR (RT-qPCR), western blot, immunohistochemistry fluorescence staining, RNA scope assay, flow cytometry and single cell RNA-sequencing. Furthermore, the change in peak nasal inspiratory flow after cold dry air provocation and visual analogue scale scores were used to evaluate NHR or disease severity, respectively. Limited gene expression of the NECs markers CHGA and ASCL1 was measured in patients with upper airway diseases and controls. Gene expression of these markers did not correlate with NHR severity nor disease severity. In vitro, CHGA and ASCL1 expression was also evaluated in primary nasal epithelial cell cultures from patients with upper airway disease and controls using RT-qPCR and western blot. Both on gene and protein level only limited CHGA and ASCL1 expression was found. Additionally, NECs were studied in nasal biopsies of patients with upper airway diseases and controls using immunohistochemistry fluorescence staining, RNA scope and flow cytometry. Unlike in ileum samples, CHGA could not be detected in nasal biopsies of patients with upper airway diseases and control subjects. Lastly, single cell RNA-sequencing of upper airway tissue could not identify a NEC cluster. In summary, in contrast to the bronchi and gut, there is only limited evidence for the presence of NECs in the nasal mucosa, and without correlation with NHR, thereby questioning the relevance of NECs in upper airway pathology.

Nasal Obstruction: Overview of Pathophysiology and Presentation of a Clinically Relevant Preoperative Plan for Rhino(Septo)plasty

Impairment of nasal breathing is a highly prevalent and bothersome symptom that affects daily functioning and/or sleep quality. Those surgeons dealing with patients seeking rhinoplasty need to carefully analyze the preoperative nasal breathing capacity and predict the positive or even negative impact of rhino(septo)plasty on nasal breathing. Given the lack of correlation between the subjective feeling of suboptimal nasal breathing and the objective measurements of nasal flow and nasal resistance, a critical and mainly clinical evaluation of all anatomical, mucosal, and sensory mechanisms involved in nasal obstruction is mandatory. Indeed, thermo-, mechano-, and chemosensory receptors on the nasal mucosa, airflow, and respiratory dynamics might all contribute to the overall perception of nasal breathing capacity. In this review, we provide an overview of the factors determining suboptimal nasal breathing including different diagnostic and experimental tests that can be performed to evaluate nasal flow and nasal resistance and current limitations in our understanding of the problem of nasal breathing in an individual patient. An algorithm for the preoperative or diagnostic workup for nasal obstruction is included that might be useful as a guide for clinicians dealing with patients seeking nose surgery.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Epithelial and sensory mechanisms of nasal hyperreactivity

"Nasal hyperreactivity" is a key feature in various phenotypes of upper airway diseases, whereby reactions of the nasal epithelium to diverse chemical and physical stimuli are exacerbated. In this review, we illustrate how nasal hyperreactivity can result from at least three types of mechanisms: (1) impaired barrier function, (2) hypersensitivity to external and endogenous stimuli, and (3) potentiation of efferent systems. We describe the known molecular basis of hyperreactivity related to the functional impairment of epithelial cells and somatosensory innervation, and indicate that the thermal, chemical, and mechanical sensors determining hyperreactivity in humans remain to be identified. We delineate research directions that may provide new insights into nasal hyperreactivity associated with rhinitis/rhinosinusitis pathophysiology and therapeutics. The elucidation of the molecular mechanisms underlying nasal hyperreactivity is essential for the treatment of rhinitis according to the precepts of precision medicine.

The Microbiology of Acute Exacerbations in Chronic Rhinosinusitis - A Systematic Review

Background

Acute exacerbations (AE) in chronic rhinosinusitis (CRS) are a common and important clinical issue. However, relatively little is known regarding the underlying microbiology that drives exacerbations or how it relates to the microbiome of CRS. The purpose of this study is to examine the literature to characterize the microbiome associated with acute exacerbations in a chronic rhinosinusitis setting. Understanding this disease process may facilitate targeted antibiotic therapy, reduced antibiotic resistance, and offer more effective disease control and treatment efficacy.

Objective

To characterize the microbiome associated with acute exacerbations of chronic rhinosinusitis (AECRS).

Methods

We conducted a systematic review of the literature on Medline, Embase, and Web of Science databases from January 1990-June 2021 to identify studies related to AE in CRS. Exclusion criteria include non-English, non-human studies, and case reports. Studies without culture or PCR data were also excluded.

Results

Fourteen studies were identified which provided detailed data regarding sinus microbiome in AECRS patients. In these patients, a total of 1252 individual isolates were identified. While common acute pathogens were identified in high frequencies in the sinonasal cultures (Staphylococcus pneumonia, Haemophilus influenza), the predominant bacteria were Staphylococcus aureus (including methicillin-sensitive Staphylococcus aureus) and Pseudomonas aeruginosa. Patient characteristics that may represent higher risk phenotypes were not consistently collected in the studies. Discussion of antimicrobial sensitivities and/or resistance were included in 7/14 studies.

Conclusions

This systematic review identifies the predominant microbiology species that may contribute to AECRS. Further studies are needed to understand the pathogenic role of bacteria and viruses in AECRS and to identify associated comorbidities and patient phenotypes that may predispose to AE. The optimal treatment regimen for AECRS remains unclear.

The prevalence of non-allergic rhinitis phenotypes in the general population: A cross-sectional study

Background

Non‐allergic rhinitis (NAR) can be subdivided into several phenotypes: rhinorrhea of the elderly, rhinitis medicamentosa, smokers', occupational, hormonal, drug‐induced, gustatory, and idiopathic rhinitis. There are two pathophysiological endotypes of NAR: inflammatory and neurogenic. Phenotypes may serve as an indicator of an underlying endotype and, therefore, help to guide the treatment. The prevalence of each phenotype in the general population is currently unknown.

Methodology/Principal

Cross‐sectional questionnaire‐based study in the general population of the Netherlands.

Results

The prevalence of chronic rhinitis in the general population was 40% (N = 558, of those, 65% had NAR and 28% AR, in 7% allergy status is unknown). Individuals with NAR (N = 363) had significantly more complaints in October–February. Those with AR (N = 159) had significantly more complaints in April–August. The most common NAR phenotypes were idiopathic (39%) and rhinitis medicamentosa (14%), followed by occupational (8%), smokers' (6%), hormonal (4%), gustatory (4%), and rhinorrhea of the elderly (4%). The least prevalent phenotype was drug induced (1%). Nineteen percent of the NAR group could not be classified into any of the phenotypes.

Conclusions

This is the first study to describe the prevalences of NAR phenotypes in the general population. AR and NAR have a distinct seasonality pattern with NAR being more prevalent in autumn/winter and AR in spring/summer. Our data on the prevalence of phenotypes may help clinicians to anticipate the type of patients at their clinic and help guide a tailored treatment approach. The high prevalence of rhinitis medicamentosa is alarming, since this is a potentially preventable phenotype.

Advances and highlights in biomarkers of allergic diseases

During the past years, there has been a global outbreak of allergic diseases, presenting a considerable medical and socioeconomical burden. A large fraction of allergic diseases is characterized by a type 2 immune response involving Th2 cells, type 2 innate lymphoid cells, eosinophils, mast cells, and M2 macrophages. Biomarkers are valuable parameters for precision medicine as they provide information on the disease endotypes, clusters, precision diagnoses, identification of therapeutic targets, and monitoring of treatment efficacies. The availability of powerful omics technologies, together with integrated data analysis and network‐based approaches can help the identification of clinically useful biomarkers. These biomarkers need to be accurately quantified using robust and reproducible methods, such as reliable and point‐of‐care systems. Ideally, samples should be collected using quick, cost‐efficient and noninvasive methods. In recent years, a plethora of research has been directed toward finding novel biomarkers of allergic diseases. Promising biomarkers of type 2 allergic diseases include sputum eosinophils, serum periostin and exhaled nitric oxide. Several other biomarkers, such as pro‐inflammatory mediators, miRNAs, eicosanoid molecules, epithelial barrier integrity, and microbiota changes are useful for diagnosis and monitoring of allergic diseases and can be quantified in serum, body fluids and exhaled air. Herein, we review recent studies on biomarkers for the diagnosis and treatment of asthma, chronic urticaria, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies, anaphylaxis, drug hypersensitivity and allergen immunotherapy. In addition, we discuss COVID‐19 and allergic diseases within the perspective of biomarkers and recommendations on the management of allergic and asthmatic patients during the COVID‐19 pandemic.

Rhinology in review: from COVID-19 to biologicals

We look back at the end of what soon will be seen as an historic year, from COVID-19 to real-world introduction of biologicals influencing the life of our patients. This review describes the important findings in Rhinology over the past year. A large body of evidence now demonstrates loss of sense of smell to be one of the most common symptoms of COVID-19 infection; a meta-analysis of 3563 patients found the mean prevalence of self-reported loss to be 47%. A number of studies have now shown long-term reduced loss of smell and parosmia. Given the high numbers of people affected by COVID-19, even with the best reported recovery rates, a significant number worldwide will be left with severe olfactory dysfunction. The most prevalent causes for olfactory dysfunction, besides COVID-19 and upper respiratory tract infections in general, are trauma and CRSwNP. For these CRSwNP patients a bright future seems to be starting with the development of treatment with biologics. This year the Nobel prize in Medicine 2021 was awarded jointly to David Julius and Ardem Patapoutian for their discoveries of receptors for temperature and touch which has greatly enhanced our understanding of nasal hyperreactivity and understanding of intranasal trigeminal function. Finally, a new definition of chronic rhinitis has been proposed in the last year and we have seen many papers emphasizing the importance of endotyping patients in chronic rhinitis and rhinosinusitis in order to optimise treatment effect.

Tackling nasal symptoms in athletes: Moving towards personalized medicine

Adequate nasal breathing is indispensable for athletes, and nasal symptoms have been shown to interfere with their subjective feeling of comfortable breathing and quality of life. Nasal symptoms are caused by either structural abnormalities or mucosal pathology. Structural pathologies are managed differently from mucosal disease, and therefore, adequate diagnosis is of utmost importance in athletes in order to choose the correct treatment option for the individual. Literature suggests that nasal symptoms are more prevalent in athletes compared to the general population and certain sports environments might even trigger the development of symptoms. Given the high demands of respiratory function in athletes, insight into triggering factors is of high importance for disease prevention. Also, it has been suggested that athletes are more neglectful to their symptoms and hence remain undertreated, meaning that special attention should be paid to education of athletes and their caregivers. This review aims at giving an overview of nasal physiology in exercise as well as the possible types of nasal pathology. Additionally, diagnostic and treatment options are discussed and we focus on unmet needs for the management and prevention of these symptoms in athletes within the concept of precision medicine.

Short Term Pre-Operative Oral Corticosteroids-Tissue Remodeling in Chronic Rhinosinusitis with Nasal Polyps

Chronic rhinosinusitis is a process involving a number of adverse changes in the mucosa of the paranasal sinuses and nasal polyps. The main histological features of tissue remodeling are changes in epithelial structure, oedema, degradation of ECM (extracellular matrix), angiogenesis, and subepithelial fibrosis. In this study, patients were divided into two groups: group 1—patients with CRSwNP (chronic rhinosinusitis with nasal polyps) taking a nasal steroid and an oral steroid in the preoperative period, and group 2—patients with CRSwNP taking only the nasal steroid in the preoperative period. All samples were subject to histopatologic evaluation. The aim of this study was to investigate the effect of oral corticosteroids and topical steroids on the tissue of paranasal sinuses. We have shown statistically significant decreases in tissue eosinophilia per 5HPF and decreased fibrosis in group 1. No significant differences were presented in the percentage of total tissue oedema, epithelium, neutrophils, basement membrane thickening and vessels. Using systemic administration of 40 mg of prednisone for seven days decreased the counts of eosinophils and decreased fibrosis in the nasal polyps tissue in CRSwNP.

New concepts in pediatric rhinitis

Rhinitis-and especially allergic rhinitis (AR)-remains the most frequent hypersensitivity condition, affecting up to a quarter of the population and impacting the quality of life of individual patients and the health economy. Data, especially with respect to underlying pathophysiologic mechanisms, mainly derive from studies on adults and are subsequently extrapolated to the pediatric population. Therapeutic algorithms for children with rhinitis are long based on the same principles as in adults. We explore and describe novel aspects of rhinitis, ranging from mechanisms to disease classification, phenotypes, diagnostic and monitoring tools, and the use of treatments, with a focus on the traits of pediatric age groups.