Chronic Rhinosinusitis and COVID-19

Olfactory dysfunction and the role of stem cells in the regeneration of olfactory neurons

The prevalence of COVID-19 has drawn increasing attention to olfactory dysfunction among researchers. Olfactory dysfunction manifests in various clinical types, influenced by numerous pathogenic factors. Despite this diversity, the underlying pathogenesis remains largely elusive, contributing to a lack of standardized treatment approaches. However, the potential regeneration of olfactory neurons within the nasal cavity presents a promising avenue for addressing olfactory dysfunction effectively. Our review aims to delve into the current research landscape and treatment modalities concerning olfactory dysfunction, emphasizing etiology, pathogenesis, clinical interventions, and the role of stem cells in regenerating olfactory nerves. Through this comprehensive examination, we aim to provide valuable insights into understanding the onset, progression, and treatment of olfactory dysfunction diseases.

Type 2 and Non-type 2 Inflammation in the Upper Airways: Cellular and Molecular Alterations in Olfactory Neuroepithelium Cell Populations

PURPOSE OF REVIEW

Neurogenesis occurring in the olfactory epithelium is critical to continuously replace olfactory neurons to maintain olfactory function, but is impaired during chronic type 2 and non-type 2 inflammation of the upper airways. In this review, we describe the neurobiology of olfaction and the olfactory alterations in chronic rhinosinusitis with nasal polyps (type 2 inflammation) and post-viral acute rhinosinusitis (non-type 2 inflammation), highlighting the role of immune response attenuating olfactory neurogenesis as a possibly mechanism for the loss of smell in these diseases.

RECENT FINDINGS

Several studies have provided relevant insights into the role of basal stem cells as direct participants in the progression of chronic inflammation identifying a functional switch away from a neuro-regenerative phenotype to one contributing to immune defense, a process that induces a deficient replacement of olfactory neurons. The interaction between olfactory stem cells and immune system might critically underlie ongoing loss of smell in type 2 and non-type 2 inflammatory upper airway diseases. In this review, we describe the neurobiology of olfaction and the olfactory alterations in type 2 and non-type 2 inflammatory upper airway diseases, highlighting the role of immune response attenuating olfactory neurogenesis, as a possibly mechanism for the lack of loss of smell recovery.

Investigating the epidemiological relevance of secretory otitis media and neighboring organ diseases through an Internet search

Background

This study examined the epidemiological correlations between secretory otitis media (SOM) and diseases of neighboring organs. We measured changes in disease incidences during the 2020 COVID-19 pandemic using Internet big data spanning from 2011 to 2021.

Methods

This study used the Baidu Index (BI) to determine the search volume for the terms "secretory otitis media (SOM)", "tonsillitis", "pharyngolaryngitis", "adenoid hypertrophy (AH)", "nasopharyngeal carcinoma (NPC)", "nasal septum deviation (NSD)", "rhinosinusitis", "allergic rhinitis (AR)", and "gastroesophageal reflux disease (GERD)" in Mandarin from January 2011 to December 2021. The correlations between these terms were analyzed using Spearman's correlation coefficients. The results were compared search data from 2019 and 2021 to assess the effects of isolation on SOM in 2020.

Results

The seasonal variations trends of SOM and other diseases coincided well (P < 0.05), except for AR. During the 11-year timeframe, the monthly searches for rhinosinusitis, NSD, tonsillitis, pharyngolaryngitis, and NPC were statistically correlated with SOM (R = 0.825, 0.594, 0.650, 0.636, 0.664, respectively; P < 0.05). No correlation was found between SOM and AR, SOM and AH, or SOM and GERD (R =  - 0.028, R = 0.259, R = 0.014, respectively, P > 0.05). The total search volumes for SOM, rhinosinusitis, NPC, and AH decreased in 2020 compared to 2019.

Discussion

SOM exhibited a discernible epidemiological connection with rhinosinusitis, nasal septal deviation (NSD), tonsillitis, pharyngolaryngitis, and nasopharyngeal carcinoma (NPC). A decrease in public gatherings was observed to effectively reduce the incidences of SOM. This underscores the pivotal role of social measures in influencing the prevalence of SOM and emphasizes the intricate interplay between SOM and various associated health factors, with implications for public health strategies.

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.

Dupilumab in chronic rhinosinusitis with nasal polyposis: current status, challenges, and future perspectives

INTRODUCTION

Chronic sinusitis with nasal polyposis (CRSwNP) is a common heterogeneous disease that mainly manifests as chronic inflammation of the sinus mucosa. The effect of conventional treatments for CRSwNP, such as oral corticosteroids, intranasal corticosteroids (INCS) and polypectomy, is not always obvious, and postoperative recurrence is common in some CRSwNP patients. In recent years, some biologics have been shown to be very effective in treating refractory CRSwNP, of which dupilumab has attracted much attention as the first monoclonal drug approved to treat nasal polyps.

AREAS COVERED

In this review, we discuss the research status of dupilumab in treatment of CRSwNP and how dupilumab differs from other treatment methods.

EXPERT OPINION

The European Union and United States have approved dupilumab as the first biological agent for treatment of CRSwNP. Dupilumab can improve symptoms of nasal congestion or obstruction, nasal secretion, and olfactory loss in patients with CRSwNP. It can also improve a patient's health-related quality of life (HR-QoL) and reduce the need for systemic corticosteroids and nasal polyp surgery. While subcutaneous injection of dupilumab is a novel method for treating CRSwNP, it is still necessary to reasonably evaluate which patients might benefit most from biological therapy.

Evaluation of Chronic Rhinosinusitis Symptoms' Severity Following COVID-19 Infection: A Retrospective Analysis

Objectives This study aims to compare the severity of chronic rhinosinusitis (CRS) symptoms pre- and post-COVID-19 infection and estimate the impact of the COVID-19 pandemic on the use of intranasal corticosteroids (ICS) among adult CRS patients. Methods This was an observational retrospective cohort study conducted at King Abdulaziz University Hospital, Riyadh, Saudi Arabia, between July 2022 and October 2022. Adult CRS patients with sino-nasal outcomes test-22 (SNOT-22) scores documented prior to March 2020, marking the occurrence of Saudi Arabia's initial reported case of COVID-19, were requested to complete the SNOT-22 questionnaire following COVID-19 infection. A comparison was subsequently made between the two scores obtained. Results The study enrolled a total of 33 patients, with 16 assigned to the control group and 17 with a history of COVID-19 infection. The mean age of the patients was 43 years, and the majority (52%) were males. Statistical analysis did not reveal any statistically significant differences in the total SNOT-22 scores or domain-level scores between the two groups. Furthermore, the use of ICS during the COVID-19 pandemic did not show any significant associations, except for patients with asthma, where 80% of them used ICS during the pandemic (p=0.0073). Conclusion There was no statistically significant disparity observed in the SNOT-22 scores between patients who tested positive for COVID-19 and those who did not. The use of corticosteroids during the COVID-19 pandemic was found to be more prevalent in this study compared to previous studies conducted before the pandemic, particularly among patients with asthma. The use of ICS during the pandemic was not associated with the presence of polyps, functional endoscopic sinus surgery (FESS), allergic rhinitis, or eczema.

Persistence of SARS-CoV-2 Antigens in the Nasal Mucosa of Eight Patients with Inflammatory Rhinopathy for over 80 Days following Mild COVID-19 Diagnosis

The nasal mucosa is the main gateway for entry, replication and elimination of the SARS-CoV-2 virus, the pathogen that causes severe acute respiratory syndrome (COVID-19). The presence of the virus in the epithelium causes damage to the nasal mucosa and compromises mucociliary clearance. The aim of this study was to investigate the presence of SARS-CoV-2 viral antigens in the nasal mucociliary mucosa of patients with a history of mild COVID-19 and persistent inflammatory rhinopathy. We evaluated eight adults without previous nasal diseases and with a history of COVID-19 and persistent olfactory dysfunction for more than 80 days after diagnosis of SARS-CoV-2 infection. Samples of the nasal mucosa were collected via brushing of the middle nasal concha. The detection of viral antigens was performed using immunofluorescence through confocal microscopy. Viral antigens were detected in the nasal mucosa of all patients. Persistent anosmia was observed in four patients. Our findings suggest that persistent SARS-CoV-2 antigens in the nasal mucosa of mild COVID-19 patients may lead to inflammatory rhinopathy and prolonged or relapsing anosmia. This study sheds light on the potential mechanisms underlying persistent symptoms of COVID-19 and highlights the importance of monitoring patients with persistent anosmia and nasal-related symptoms.

The impact of chronic rhinosinusitis on COVID-19 risk and outcomes: A systematic review and meta-analysis

Background

The impact of chronic rhinosinusitis (CRS) and subsequent steroid therapy on acquiring COVID-19 and severe outcomes remains controversial. Therefore, we conducted this systematic review and meta-analysis to provide cumulative evidence regarding the risk of COVID-19 and the impact of steroid therapy, length of hospital stay, mechanical ventilation, and mortality among CRC patients.

Methods

We conducted a comprehensive electronic search strategy using the relevant keywords. The outcomes and risk factors of COVID-19 in CRS patients was estimated and compared to a healthy control group when applicable.

Results

A total of seven studies were included, with an estimated prevalence of 6.5% (95% confidence interval (CI): 2.5-15.7) for COVID-19 in the CRS group. COVID-19 prevalence did not differ between CRS and controls (odds ratio (OR): 0.92; 95%CI: 0.84-1.01; p = 0.08). Moreover, using steroid/immunosuppressive therapy did not significantly increase the risk of acquiring COVID-19 in CRS patients compared to the control group (OR: 3.31; 95%CI: 0.72-15.26; p = 0.12). Length of hospital stay, mechanical ventilation, and mortality rates were comparable between the two groups. Furthermore, we found that male sex, cardiovascular morbidity, renal diseases, and hypertension were inversely associated with COVID-19 infection (p &lt; 0.01).

Conclusion

CRS had a neutral effect on acquiring COVID-19 and developing severe outcomes. However, further studies are needed.

Improvement of eosinophilic chronic rhinosinusitis after infection with severe acute respiratory syndrome corona virus 2 during dupilumab therapy: A case report

Eosinophilic chronic rhinosinusitis (ECRS) is an intractable type 2 inflammatory disease of the paranasal sinuses that persists even after endoscopic sinus surgery (ESS) and systemic corticosteroid therapy. Dupilumab, a monoclonal antibody against the shared receptor components of interleukin (IL)-4 and IL-13, is a novel and effective treatment option for ECRS. Herein, an atypical case of ECRS that improved after infection with severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) during dupilumab therapy is reported. A 40-year-old man with a history of ESS for ECRS visited our hospital with complaints of nasal congestion and dysosmia. Nasal endoscopy revealed bilateral nasal polyps occupying the nasal cavity. Computed tomography (CT) revealed a soft tissue density lesion filling all sinuses on both sides. Based on these findings, ECRS recurrence was confirmed; however, 3 years of subsequent corticosteroid therapy did not improve disease activity. Accordingly, dupilumab therapy was initiated, although 6 months of therapy resulted in only slight improvement in ECRS. Eight months after the initiation of dupilumab therapy, the patient was infected with SARS-CoV-2; thereafter, he noticed an improvement in smell. Nasal endoscopy and sinus CT revealed a marked reduction in nasal polyps and soft tissue density lesions of the sinuses, respectively. With continued dupilumab therapy, no re-exacerbation of ECRS was confirmed at the 6-month follow-up from SARS-CoV-2 infection. Currently, there are no reports describing the impact of SARS-CoV-2 infection on ECRS. As such, careful follow-up and accumulation of cases are necessary.

Recent developments in the immunopathology of COVID-19

There has been an important change in the clinical characteristics and immune profile of Coronavirus disease 2019 (COVID-19) patients during the pandemic thanks to the extensive vaccination programs. Here, we highlight recent studies on COVID-19, from the clinical and immunological characteristics to the protective and risk factors for severity and mortality of COVID-19. The efficacy of the COVID-19 vaccines and potential allergic reactions after administration are also discussed. The occurrence of new variants of concerns such as Omicron BA.2, BA.4, and BA.5 and the global administration of COVID-19 vaccines have changed the clinical scenario of COVID-19. Multisystem inflammatory syndrome in children (MIS-C) may cause severe and heterogeneous disease but with a lower mortality rate. Perturbations in immunity of T cells, B cells, and mast cells, as well as autoantibodies and metabolic reprogramming may contribute to the long-term symptoms of COVID-19. There is conflicting evidence about whether atopic diseases, such as allergic asthma and rhinitis, are associated with a lower susceptibility and better outcomes of COVID-19. At the beginning of pandemic, the European Academy of Allergy and Clinical Immunology (EAACI) developed guidelines that provided timely information for the management of allergic diseases and preventive measures to reduce transmission in the allergic clinics. The global distribution of COVID-19 vaccines and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with reduced pathogenic potential dramatically decreased the morbidity, severity, and mortality of COVID-19. Nevertheless, breakthrough infection remains a challenge for disease control. Hypersensitivity reactions (HSR) to COVID-19 vaccines are low compared to other vaccines, and these were addressed in EAACI statements that provided indications for the management of allergic reactions, including anaphylaxis to COVID-19 vaccines. We have gained a depth knowledge and experience in the over 2 years since the start of the pandemic, and yet a full eradication of SARS-CoV-2 is not on the horizon. Novel strategies are warranted to prevent severe disease in high-risk groups, the development of MIS-C and long COVID-19.

The effects of comorbidities on the change of taste and smell in COVID-19 patients

Background

Sudden chemosensory changes were considered an early predictor of COVID-19. Here, the effects of comorbidities on changes in taste and smell in COVID-19 patients were investigated based on a worldwide study.

Methods

Data analyzed here were collected from the Global Consortium for Chemosensory Research (GCCR) core questionnaire, including questions regarding preexisting disease conditions. Overall, the final sample of 12,438 participants who were diagnosed with COVID-19 included patients with preexisting conditions. Mixed linear regression models were used to test our hypothesis, and the p-value of interaction was examined.

Results

A total of 61,067 participants completed the GCCR questionnaire, including 16,016 participants had preexisting diseases. The multivariate regression analysis showed that individuals with high blood pressure, lung disease, or sinus problems, or neurological diseases exhibited worse self-reported smell loss (p < .05), but no apparent significant differences in the smell or taste recovery. COVID-19 patients with seasonal allergy/hay fever lost their olfactory ability more than patients who did not have it (with 11.90 [9.67, 14.13] vs. without 6.97 [6.04, 7.91], p < .0001). The taste ability, smell loss and taste loss after COVID-19 recovery also decreased in the COVID-19 patients with seasonal allergy/hay fever (p < .001). Preexisting condition of diabetes did not worsen to chemosensory disorder but also had no obvious impact on the chemosensory recovery after acute infection. Preexisting diseases also affected the type of smell change in the COVID-19 patients with seasonal allergy/hay fever or sinus problems (p < .05).

Conclusions

COVID-19 patients with high blood pressure, lung disease, or sinus problems, or neurological diseases exhibited worse self-reported smell loss, but no differences in the smell or taste recovery. COVID-19 patients with seasonal allergy/hay fever had greater loss of smell and taste, poorer smell and taste recovery.

Level of Evidence

4.

Pathophysiology of SARS-CoV-2 Infection of Nasal Respiratory and Olfactory Epithelia and Its Clinical Impact

PURPOSE OF REVIEW

While the predominant cause for morbidity and mortality with SARS-CoV-2 infection is the lower respiratory tract manifestations of the disease, the effects of SARS-CoV-2 infection on the sinonasal tract have also come to the forefront especially with the increased recognition of olfactory symptom. This review presents a comprehensive summary of the mechanisms of action of the SARS-CoV-2 virus, sinonasal pathophysiology of COVID-19, and the correlation with the clinical and epidemiological impact on olfactory dysfunction.

RECENT FINDINGS

ACE2 and TMPRSS2 receptors are key players in the mechanism of infection of SARS-CoV-2. They are present within both the nasal respiratory as well as olfactory epithelia. There are however differences in susceptibility between different groups of individuals, as well as between the different SARS-CoV-2 variants. The sinonasal cavity is an important route for SARS-CoV-2 infection. While the mechanism of infection of SARS-CoV-2 in nasal respiratory and olfactory epithelia is similar, there exist small but significant differences in the susceptibility of these epithelia and consequently clinical manifestations of the disease. Understanding the differences and nuances in sinonasal pathophysiology in COVID-19 would allow the clinician to predict and counsel patients suffering from COVID-19. Future research into molecular pathways and cytokine responses at different stages of infection and different variants of SARS-CoV-2 would evaluate the individual clinical phenotype, prognosis, and possibly response to vaccines and therapeutics.

A Decade of Clinical Advances in Chronic Rhinosinusitis: 2012-2022

The field of chronic rhinosinusitis (CRS) is constantly evolving. In the past 10 years, key advancements in basic and translational research as well as clinical studies have improved our understanding and management of CRS. Notably, treatment options have expanded to include novel therapeutic drugs, devices, and surgical techniques. Assessments of patient symptoms and their impact on quality of life have become more standardized. Progress has also been made in both determining the true prevalence of CRS and recognizing comorbidities that can impact CRS severity. Practice guidelines have also shifted from expert opinion to more data-driven analyses. This review highlights major clinical advancements made in the field of CRS over the past 10 years as well as identifies current gaps in knowledge that can form the basis for new areas of study over the next decade.

COVID-19 Co-Infection May Promote Development of Sinusitis Complication in Children

BACKGROUND

The olfactory dysfunction that occurs during a COVID-19 infection has sparked much debate about its similarity to sinusitis. Up to 65% of COVID-19 pediatric patients may be asymptomatic; however, when symptoms are observed, fever and cough are the most common. Nasal congestion and discharge as well as headaches can also be seen, which makes both entities, i.e., COVID-19 and sinusitis, similar to each other.

METHODS

In this review, we present the clinical case of a teenager with a history of acute sinusitis and COVID-19 co-infection followed by purulent meningoencephalitis. We aim to summarize available findings on the association between COVID-19, sinusitis, and possible common complications of both diseases.

RESULTS

Differentiating between COVID-19 and sinusitis can be confusing because presented symptoms may overlap or mimic each other. Increased risk of complications, especially in patients with bacterial sinusitis co-infected with SARS-CoV-2, should prompt physicians to monitor young patients and inform parents about disturbing symptoms and possible complications.

CONCLUSIONS

Acute sinusitis and COVID-19 co-infection may lead to numerous complications and should be included among the factors predisposing to worse prognosis. It is especially related to patients with high risk factors and even more important in children as they often pass the infection asymptomatically and its complications can lead to loss of health or life.

Olfactory training - Thirteen years of research reviewed

The sense of smell is interrelated with psychosocial functioning. Olfactory disorders often decrease quality of life but treatment options for people with olfactory loss are limited. Additionally, olfactory loss accompanies and precedes psychiatric and neurodegenerative diseases. Regular, systematic exposure to a set of odors, i.e., olfactory training (OT) has been offered for rehabilitation of the sense of smell in clinical practice. As signals from the olfactory bulb are directly projected to the limbic system it has been also debated whether OT might benefit psychological functioning, i.e., mitigate cognitive deterioration or improve emotional processing. In this review we synthesize key findings on OT utility in the clinical practice and highlight the molecular, cellular, and neuroanatomical changes accompanying olfactory recovery in people with smell loss as well as in experimental animal models. We discuss how OT and its modifications have been used in interventions aiming to support cognitive functions and improve well-being. We delineate main methodological challenges in research on OT and suggest areas requiring further scientific attention.