Inflammatory endotypes of CRSwNP and responses to COVID-19.

PURPOSE OF REVIEW: Coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly become a great public health hazard globally. Nasal epithelial cells are an important site for SARS-CoV-2 infection and replication. The purpose of this review is to summarize recent findings on the endotypes of chronic rhinosinusitis with nasal polyps (CRSwNP) and the potential impact of SARS-CoV-2 infection. RECENT FINDINGS: Endotypes of CRSwNP are characterized by type 1, type 2 and type 3 inflammation according to patterns of inflammatory cells and the cytokines expressed in nasal tissue. Nasal epithelial cells show the highest expression of angiotensin-converting enzyme 2 (ACE2), the receptor for attachment and entry of SARS-CoV-2 into host cells, among all investigated cells in the respiratory tree. SARS-CoV-2 infection likely leads to increased activation of T-helper-1 (Th1) cell responses. Recent studies further suggest that ACE2 may be upregulated by type 1 and downregulated by type 2 inflammatory cytokines in nasal epithelial cells. SUMMARY: Expression of ACE2 in nasal epithelial cells is influenced by inflammatory endotypes of CRSwNP. Type 1 inflammation in nasal tissue may increase the risk of SARS-CoV-2 infection by upregulating ACE2 expression. However, clinical association between CRSwNP and COVID-19 is still unclear.

The impact of COVID-19 outbreak on the incidence of acute invasive fungal rhinosinusitis.

BACKGROUND: Acute invasive fungal rhinosinusitis (AIFRS) is aggressive morbidity affecting immunocompromised patients. Coronavirus disease 2019 (COVID-19) may allow secondary fungal disease through a propensity to cause respiratory infection by affecting the immune system leading to dysregulation and reduced numbers of T lymphocytes, CD4+T, and CD8+T cells, altering the innate immunity. The aim of this study is to evaluate the incidence of acute invasive fungal rhinosinusitis (AIFRS) in COVID-19 patients. METHODOLOGY: Data for acute invasive rhinosinusitis was obtained from the Otorhinolaryngology departments at our tertiary hospital at the period from January 2017 to December 2020. Then the risk factors of comorbid diseases and fungal types between post-COVID-19 and non-COVID-19 groups regarding the incidence of AIFRS are compared. RESULTS: Consequently, the incidence of AIFRS showed a more significant difference (P < 0.05) in post-COVID-19 patients than in non-COVID-19 especially in immunocompromised patients, diabetic, renal, and liver dysfunction patients as well as patients with risk factors of AIFRS. The most common organisms affecting patients with AIFRS are Rhizopus oryzae, Aspergillus fumigatus, and Absidia mucor. CONCLUSIONS: The incidence of AIFRS is markedly prominent in post-COVID-19 patients than in those of non-COVID-19, especially in immunocompromised, diabetic, renal, and liver dysfunction patients and patients with risk factors for rhinosinusitis.

EUFOREA expert board meeting on uncontrolled severe chronic rhinosinusitis with nasal polyps (CRSwNP) and biologics: Definitions and management.

Uncontrolled severe chronic rhinosinusitis with nasal polyps (CRSwNP) is the most bothersome phenotype of chronic rhinosinusitis; it is typically characterized by a type 2 inflammatory reaction and by comorbidities, including asthma, nonsteroidal anti-inflammatory drug-exacerbated respiratory disease, and allergies. Here, the European Forum for Research and Education in Allergy and Airway Diseases proposes structured definitions to enable communication between clinicians and provides a practical algorithm to define type 2 inflammation in CRSwNP in daily clinical practice. A rational approach for the treatment of uncontrolled severe CRSwNP is discussed; it consists of evaluating the perspective and risks of surgery and efficacy and adverse events of biologics on the basis of currently available data. Further, possible combinations of surgery and biologics are discussed, and a rationale is provided. Here, it is of importance to adequately counsel the patient about both approaches to enable a decision-making process with an informed patient. Criteria for the selection of a biologic drug are provided, as several biologics for uncontrolled severe CRSwNP will be available in many countries within a short time. Further, suggestions for monitoring of the drug effects that support recognition of responders to the therapy and, subsequently, the decision regarding continuation or discontinuation of the biologic are proposed.

Biomolecular endotype factors involved in COVID-19 airway infectivity: A systematic review.

OBJECTIVES: To review the current knowledge of biomolecular factors surrounding otorhinolaryngeal illnesses and analyze their presence in COVID-19 virulence. Emphasis was placed on cytokines and vitamin D for determining susceptibility of illness. METHODS: A primary literature search of PubMed and Google Scholar for articles published between January 1, 2002 to May 31, 2020, was performed without language restrictions from May 8, 2020 to May 31, 2020. A focused second search was conducted from October 31, 2020 to November 2, 2020 for articles published between January 1, 2002 to October 31, 2020. Eligible articles were selected after evaluation of titles, abstracts, and references. A total of 45 were included in this review. RESULTS: Differing endotype classification schemes are used to determine cytokines present in chronic rhinosinusitis, asthma, and allergies. While immunologic responses and biomarkers are primary methods of differentiation, recent literature has also implicated geographic distribution of chronic rhinosinusitis patients in accounting for cytokine variations. The cytokines of interest (IL-4, IL-13, and INF-γ) present in the endotypes of these conditions may point towards protective mechanisms against COVID-19 through downregulation of the ACE2 receptor. These cytokines and Vitamin D highlight new areas of study for factors affecting SARS-CoV-2 virulence. CONCLUSIONS: Further research is needed to understand the effects of Vitamin D and the various cytokines prevalent among endotypes of nasal/pharyngeal illnesses on COVID-19 pathogenesis. Findings may point towards epidemiologic trends of SARS-CoV-2 transmission and have future therapeutic indications.

Distinct expression of SARS-CoV-2 receptor ACE2 correlates with endotypes of chronic rhinosinusitis with nasal polyps.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry factors, ACE2 and TMPRSS2, are highly expressed in nasal epithelial cells. However, the association between SARS-CoV-2 and nasal inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been investigated. We thus investigated the expression of SARS-CoV-2 entry factors in nasal tissues of CRSwNP patients, and their associations with inflammatory endotypes of CRSwNP. METHODS: The expression of ACE2 and TMPRSS2 was assessed in nasal tissues of control subjects and eosinophilic CRSwNP (ECRSwNP) and nonECRSwNP patients. The correlations between ACE2/TMPRSS2 expression and inflammatory indices of CRSwNP endotypes were evaluated. Regulation of ACE2/TMPRSS2 expression by inflammatory cytokines and glucocorticoids was investigated. RESULTS: ACE2 expression was significantly increased in nasal tissues of nonECRSwNP patients compared to ECRSwNP patients and control subjects, and positively correlated with the expression of IFN-γ, but negatively correlated with tissue infiltrated eosinophils, and expression of IL5 and IL13. IFN-γ up-regulated ACE2 expression while glucocorticoid attenuated this increase in cultured nasal epithelial cells. Genes co-expressed with ACE2 were enriched in pathways relating to defence response to virus in nasal tissue. TMPRSS2 expression was decreased in nasal tissues of CRSwNP patients compared to control subjects and not correlated with the inflammatory endotypes of CRSwNP. Glucocorticoid treatment decreased ACE2 expression in nasal tissues of nonECRSwNP patients, but not in ECRSwNP patients, whereas TMPRSS2 expression was not affected. CONCLUSION: These findings indicate that ACE2 expression, regulated by IFN-γ, is increased in nasal tissues of nonECRSwNP patients and positively correlates with type 1 inflammation.