Multiple instance learning for eosinophil quantification of sinonasal histopathology images: A hierarchical determination on whole slide images.

KEY POINTS: We proposed a hierarchical framework including an unsupervised candidate image selection and a weakly supervised patch image detection based on multiple instance learning (MIL) to effectively estimate eosinophil quantities in tissue samples from whole slide images. MIL is an innovative approach that can help deal with the variability in cell distribution detection and enable automated eosinophil quantification from sinonasal histopathological images with a high degree of accuracy. The study lays the foundation for further research and development in the field of automated histopathological image analysis, and validation on more extensive and diverse datasets will contribute to real-world application.

Modified screening and management strategies for chronic rhinosinusitis in hematologic patients receiving hematopoietic stem cell transplantation.

OBJECTIVES: Given the lack of consensus on the screening and treatment for chronic rhinosinusitis (CRS) in the patients undergoing hematopoietic stem cell transplantation (HSCT), we reviewed the risk factors for CRS to improve the efficiency of sinonasal screening and analyzed the effect of treating CRS in search of guidance for modifying current management strategies for rhinosinusitis in HSCT patients. METHODS: We conducted a nested case-control study in a retrospective cohort of hematologic patients receiving HSCT from April 2011 to April 2021 and collected data on demographics, smoking/atopic status, hematological diseases, and features of rhinosinusitis for analysis. The associated factors for control of rhinosinusitis and survival were analyzed. RESULTS: Fifty-eight CRS patients were identified, and another 116 age- and sex-matched controls were selected from HSCT patients without CRS. Allergy and smoking were risk factors for CRS in HSCT patients. The multivariable logistic analysis indicated that endoscopic sinus surgery (ESS) was an independent factor for better control of CRS. However, survival was not associated with rhinosinusitis-related factors, but only with hematologic-related factors, including allogenic HSCT, reduced-intensity conditioning, and remission. CONCLUSIONS: Sinonasal evaluation should be targeted to the high-risk group. ESS is effective in managing CRS, while control of CRS is not determinant of overall survival in patients receiving HSCT.

Craniofacial and olfactory sensory changes after long-term unilateral nasal obstruction-an animal study using MMP-3-LUC transgenic rats.

Nasal obstruction exerts considerable physiological effects on the respiratory system and craniofacial morphology during the developmental stage. This study used MMP-3-LUC transgenic rats for in vivo tracking of long-term expression in the rat nasal region after unilateral nasal obstruction. Skeletal changes of the craniofacial, nasal, and sinus regions were measured through micro-computed tomography examination and analysis with 3D image processing and calculation. Matrix metalloproteinase-3 and olfactory marker protein expression were also investigated through immunohistochemistry (IHC). Unilateral nasal obstruction significantly reduced the MMP-3 signal in the nasal region of MMP-3-LUC transgenic rats, which was mainly expressed in the respiratory epithelium. Long-term obstruction also caused morphological changes of the craniofacial hard tissue, such as nasal septal deviation, longer inter-jaw distance, and increased maxillary molar dental height. It also caused compensatory growth in olfactory nerve bundles and the olfactory epithelium, as confirmed by IHC. In our study, long-term unilateral nasal obstruction caused nasal septal deviation toward the unobstructed side, hyper divergent facial development including longer molar dental height, and reduced MMP-3 production. However, further investigation is necessary to explore the mechanism in depth.

Comprehensive evaluation of type 2 endotype and clinical features in patients with chronic rhinosinusitis with nasal polyps in Taiwan: a cross-sectional study.

PURPOSE: Endotype-driven treatment has been introduced in the management of chronic rhinosinusitis with nasal polyps (CRSwNP), and an understanding of the associations between phenotypes and endotypes of CRSwNP will be beneficial in identifying responders. We aimed to determine the correlations between clinical manifestations and type 2 inflammatory mediators of sinonasal tissues. METHODS: Adult patients undergoing endoscopic sinus surgery for bilateral CRSwNP were prospectively enrolled. Tissue eosinophilia and type 2 mediator expression in tissue homogenates were assessed and correlated with clinical features, including symptoms, comorbidities, blood eosinophil counts, specific allergen immunoglobulin (IgE) testing, computed tomography (CT) scan findings, and Sino-Nasal Outcome Test-22 scores. RESULTS: A total of 93 subjects were recruited in our study. Fifty-nine (63.4%) cases were identified as the eosinophilic endotype, demonstrating with higher rates of comorbidity of asthma, blood eosinophilia and a high ethmoid-maxillary ratio on CT images. To correlate of phenotypes with the inflammatory mediator profile, multivariate analyses revealed the associations of IgE expression in nasal polyp tissues with allergen sensitization (p = 0.042), CT ethmoid-maxillary ratio (p = 0.001) and tissue eosinophil counts (p = 0.022); the association of interleukin (IL-5) expression with the blood eosinophil percentage (p = 0.020); and the association of IL-13 expression with white blood cell count (p = 0.002) and central compartment-type inflammation (p < 0.001). CONCLUSION: We demonstrated associations of IgE and IL-5 expression with clinical features of eosinophilic-type inflammation and a significantly elevated level of IL-13 in patients with central-compartment-type CRSwNP. These observations may be useful when considering the use of type 2 biologic treatment and require further validation studies.

Recent Updates of Immunotherapy for Allergic Rhinitis in Children.

Purpose of Review: Allergen immunotherapy (AIT) is a novel treatment approach with disease-modifying and preventative benefits that are not shared with other strategies for treating allergic illnesses. It has been demonstrated to be safe and effective in children. This review provides the most recent information on AIT in children as well as any pertinent updates. Recent Findings: Although there is not a standard way to begin AIT, there are clear indications for AIT. Each case needs to be evaluated on its own by weighing the pros and downsides. AIT has been proven to significantly improve symptoms and quality of life in children with allergic illness, reduce medication use, stop the development of new allergen sensitizations, and stop the progression of allergic rhinitis to asthma. Novel approaches are under investigation to overcome some known AIT disadvantages. Summary: This review provides a thorough summary of the most recent research and updates on AIT in children.

Revision of endoscopic sinus surgery in adults: A population-based study in Taiwan.

OBJECTIVE: This study aimed to elucidate the revision rate, time to revision, and factors associated with revision of endoscopic sinus surgery (ESS) in Taiwan. DESIGN: Retrospective study. SETTING: Population-based analysis. PARTICIPANT: We identified all in-hospital patients, aged >20 years, who underwent ESS between 2000 and 2008 from the Taiwan National Health Insurance Research Database, and followed up with them until 2018. MAIN OUTCOME MEASURES: Factors associated with revision surgery were analyzed using multivariable Cox proportional hazard model. RESULTS: Overall, 66 592 patients were identified (mean age, 46.3 years; 62% males). The revision rate was 14.5% (9644/66 592) and time to revision surgery was 5.9 years. Multivariable Cox proportional hazard model showed that young age, male gender (hazard ratio [HR] = 1.18; 95% confidence interval [CI], 1.13-1.23), having nasal polyposis (HR = 1.17; 95% CI, 1.12-1.22), having allergic rhinitis (HR = 1.08; 95% CI, 1.04-1.13), having asthma (HR = 1.26; 95% CI, 1.14-1.39), and surgical time of >4 h (HR = 1.11; 95% CI, 1.06-1.16) were associated with increased risk of revision surgery. Concurrent septal surgery (HR = 0.81; 95% CI, 0.76-0.87), turbinate surgery (HR = 0.91; 95% CI, 0.85-0.97), or septal and turbinate surgery (HR = 0.68; 95% CI, 0.64-0.73) were associated with decreased risks of revision surgery. CONCLUSION: In Taiwan, risk factors for revision ESS are young age, male gender, having nasal polyposis, having allergic rhinitis, having asthma, and long surgical times. Concurrent septal or turbinate surgery decreases the risk of revision.

Improved nasal recovery and intact olfactory function after a transseptal approach for endoscopic endonasal transsphenoidal adenomectomy: A retrospective analysis.

Objectives: Endoscopic endonasal transsphenoidal adenomectomy (TSA) is the most frequently performed skull base surgery, and researchers have recently focused on preserving nasal function. The endoscopic transseptal approach is a promising procedure due to its reduced injury to the nasal mucosa; however, there are no studies comparing rhinological and neurosurgical outcomes concurrently with the standard endoscopic transnasal approach. Therefore, we conducted this study to investigate whether the transseptal approach could reduce nasal morbidities with comparable neurosurgical outcomes. Methods: We retrospectively reviewed 25 patients who underwent endoscopic endonasal transseptal TSA for pituitary adenoma without encasement of internal carotid artery from January 2019 to December 2020. Another 25 patients who received transnasal approach from January 2017 to December 2018 were selected as controls. Patients with diseases affecting the nasal cavity/olfaction or usage of a nasoseptal flap were excluded for a better comparison of the two procedures. We collected data from radiological studies, endocrine studies, endoscopic evaluations, 22-item sinonasal outcome tests (SNOT-22) and Top International Biotech Smell Identification Test (TIBSIT) for comparison. Results: Lower postoperative SNOT-22 and Lund-Kennedy endoscopic scores were observed in the transseptal group. The effect size of differences were classified as large effect (The absolute value of Cohen's d > 0.8). Nevertheless, the TIBSIT scores were not significantly different. The rates of gross total resection, recovery of hormonal abnormalities, and complications were not significantly different. After controlling possible confounding factors using multivariate analysis, the endoscopic transseptal approach remained an independent factor for lower SNOT-22 scores and Lund-Kennedy endoscopic scores. Conclusions: The endoscopic transseptal approach provides improved recovery of nasal mucosa and intact olfaction without compromising neurosurgical outcomes. Level of Evidence: 2b.

Effect of Sleep Surgery on Inflammatory Cytokines in Adult Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis.

OBJECTIVE: To evaluate whether sleep surgery is associated with inflammatory cytokine changes. This study hypothesizes cytokines may change after surgery in adult obstructive sleep apnea (OSA). STUDY DESIGN: Systematic review and meta-analysis. METHODS: The study protocol was registered on PROSPERO (CRD42020154425). Two authors independently searched PubMed, Embase, and Cochrane review databases from their inception to June 2021. The keywords used were sleep apnea, inflammatory markers, cytokines, and surgery. The effects of sleep surgery on the apnea-hypopnea index (AHI) and inflammatory cytokines were evaluated using a random-effects model. Both mean difference (MD) and standardized mean difference (SMD) of the changes in cytokines were calculated. RESULTS: Nine studies with 235 adults were included (mean age: 43 years; 82% were men). After sleep surgery, AHI significantly reduced by -11.3 events/h (95% confidence interval [CI], -15.8 to -6.9). In total, 8 and 6 studies were pooled for examining tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels, respectively. Sleep surgery significantly reduced TNF-α levels, with an MD of -2.8 pg/ml (95% CI, -5.1 to -0.6) and an SMD of -0.56 (95% CI, -0.85 to -0.27). Furthermore, sleep surgery reduced IL-6 levels, with an MD of -0.6 pg/ml (95% CI, -1.0 to -0.2) and an SMD of -0.66 (95% CI, -0.89 to -0.43). No covariates were identified to be correlated with cytokine changes in subgroup and meta-regression analyses. Funnel plots showed possible publication bias in current data. CONCLUSIONS: In adults, OSA treatment with sleep surgery improves inflammatory cytokines. Laryngoscope, 132:2275-2284, 2022.

Effect of sleep surgery on lipid profiles in adults with obstructive sleep apnea: a meta-analysis.

PURPOSE: The effects of sleep surgery on the lipid profile of adults diagnosed as having obstructive sleep apnea (OSA) remain unclear. This meta-analysis aimed to clarify whether sleep surgeries improve patients' lipid profile. METHODS: The study protocol was registered on PROSPERO (CRD42020154425). Two authors independently searched the PubMed, MEDLINE, EMBASE, and Cochrane review databases up to September 2020 using keywords such as sleep apnea, OSA, sleep apnea syndromes, lipids, and surgery. The effects of sleep surgery on the apnea-hypopnea index (AHI) and lipid profile parameters were evaluated using a random-effects model. RESULTS: Thirteen studies were included, with a total of 710 patients (mean age: 42.0 years; 85% men; mean sample size: 54.6 patients). The summary estimate of AHI change was - 20.6 events/h (95% CI - 25.9 to - 15.3) and the Epworth Sleepiness Scale score was - 4.2 (95% CI - 5.9 to - 2.5). Sleep surgery lowered total cholesterol (mean - 7.7 mg/dL; 95% CI - 12.2 to - 3.2), low-density lipoprotein (mean - 7.2 mg/dL; 95% CI - 11.0 to - 3.3), and triglyceride (mean - 14.0 mg/dL; 95% CI - 22.2 to - 5.8) levels but did not affect high-density lipoprotein (mean 1.5 mg/dL; 95% CI - 0.6 to 3.7) levels. Subgroup analysis revealed that the lipid profile changes were not associated with the surgical procedure but with the degree of OSA improvement. Meta-regression analyses demonstrated that the improvement in the lipid profile was positively correlated with AHI reduction. CONCLUSION: Surgeries for OSA may improve the lipid profile, which is positively correlated with the degree of OSA improvement.

Studies on Clinical Features, Mechanisms, and Management of Olfactory Dysfunction Secondary to Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) is one of the most common causes of inflammation of the olfactory system, warranting investigation of the link between chronic inflammation and the loss of olfactory function. Type 2 inflammation is closely related to the clinical features and disease mechanisms of olfactory dysfunction secondary to CRS. Patients with eosinophilic CRS, aspirin-exacerbated respiratory disease, and central compartment atopic disease report increased olfactory dysfunction. Increased levels of interleukin-(IL-)2, IL-5, IL-6, IL-10, and IL-13 in the mucus from the olfactory slit have been reported to be associated with reduced olfactory test scores. The influence of several cytokines and signaling transduction pathways, including tumor necrosis factor-α, nuclear factor-κB, and c-Jun N-terminal kinases, on olfactory signal processing and neurogenesis has been demonstrated. Corticosteroids are the mainstay treatment for olfactory dysfunction secondary to CRS. Successful olfaction recovery was recently demonstrated in clinical trials of biotherapeutics, including omalizumab and dupilumab, although the treatment effect may diminish gradually after stopping the use of the medications. Future studies are required to relate the complex mechanisms underlying chronic inflammation in CRS to dysfunction of the olfactory system.

Epstein-Barr Virus Enhances Cancer-Specific Aberrant Splicing of TSG101 Pre-mRNA.

Tumor viruses gain control of cellular functions when they infect and transform host cells. Alternative splicing is one of the cellular processes exploited by tumor viruses to benefit viral replication and support oncogenesis. Epstein-Barr virus (EBV) participates in a number of cancers, as reported mostly in nasopharyngeal carcinoma (NPC) and Burkitt lymphoma (BL). Using RT-nested-PCR and Northern blot analysis in NPC and BL cells, here we demonstrate that EBV promotes specific alternative splicing of TSG101 pre-mRNA, which generates the TSG101∆154-1054 variant though the agency of its viral proteins, such as EBNA-1, Zta and Rta. The level of TSG101∆154-1054 is particularly enhanced upon EBV entry into the lytic cycle, increasing protein stability of TSG101 and causing the cumulative synthesis of EBV late lytic proteins, such as VCA and gp350/220. TSG101∆154-1054-mediated production of VCA and gp350/220 is blocked by the overexpression of a translational mutant of TSG101∆154-1054 or by the depletion of full-length TSG101, which is consistent with the known role of the TSG101∆154-1054 protein in stabilizing the TSG101 protein. NPC patients whose tumor tissues express TSG101∆154-1054 have high serum levels of anti-VCA antibodies and high levels of viral DNA in their tumors. Our findings highlight the functional importance of TSG101∆154-1054 in allowing full completion of the EBV lytic cycle to produce viral particles. We propose that targeting EBV-induced TSG101 alternative splicing has broad potential as a therapeutic to treat EBV-associated malignancies.

Effect of sleep surgery on blood pressure in adults with obstructive sleep apnea: A Systematic Review and meta-analysis.

This meta-analysis evaluates the effect of sleep surgery on blood pressure (BP) in adults with OSA. The study protocol was registered on PROSPERO (CRD42020154425). The PubMed, MEDLINE, EMBASE, and Cochrane databases were independently searched by 2 authors up to March 2020. The keywords used were sleep apnea, OSA, sleep apnea syndromes, surgery, and BP. In 26 studies with 1218 patients (mean age: 46.2 years; 82% men), the mean AHI significantly decreased by 26.2 (95% confidence interval [CI], 21.2 to 31.1) events/hour after sleep surgery. Overall, sleep surgery resulted in a significant reduction in office systolic and diastolic BP by 5.6 mmHg (95% CI, 2.9 to 8.3) and 3.9 mmHg (95% CI, 1.8 to 6.0), respectively, in adults with OSA. According to subgroup analyses, differences in the office BP after sleep surgery were nonsignificant between regions (ie, western vs eastern countries), sample sizes, surgical procedures (ie, pharyngeal surgery vs other surgical procedures), and follow-up periods. Meta-regression analyses revealed that reductions in systolic and diastolic BP were positively correlated with the AHI reduction. In conclusion, sleep surgery significantly reduces BP and AHI in adults with OSA. The BP reduction degree after sleep surgery is positively correlated with the OSA improvement degree.

Endonasal and Endoscopic Repair of Nasal Septal Perforation with an Autologous Fascia Lata Graft.

Importance: We propose a novel technique utilizing both a headlight and an endoscope to repair large iatrogenic septal perforations using autologous fascia lata grafts and extended pedicled mucosal flaps. Objective: The use of an autologous fascia graft, a fat graft, and an extended pedicled mucosal flap enables the closure of a large and anterior perforation of the nasal septum. This approach is an effective and applicable method for nasal septal perforation repair.

Determinants of SARS-CoV-2 entry and replication in airway mucosal tissue and susceptibility in smokers.

Understanding viral tropism is an essential step toward reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, decreasing mortality from coronavirus disease 2019 (COVID-19) and limiting opportunities for mutant strains to arise. Currently, little is known about the extent to which distinct tissue sites in the human head and neck region and proximal respiratory tract selectively permit SARS-CoV-2 infection and replication. In this translational study, we discover key variabilities in expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), essential SARS-CoV-2 entry factors, among the mucosal tissues of the human proximal airways. We show that SARS-CoV-2 infection is present in all examined head and neck tissues, with a notable tropism for the nasal cavity and tracheal mucosa. Finally, we uncover an association between smoking and higher SARS-CoV-2 viral infection in the human proximal airway, which may explain the increased susceptibility of smokers to developing severe COVID-19. This is at least partially explained by differences in interferon (IFN)-ß1 levels between smokers and non-smokers.

Clinical characteristics and cytokine profiles of central-compartment-type chronic rhinosinusitis.

BACKGROUND: The clinical characteristics of central-compartment-type chronic rhinosinusitis (CRS) in East Asian individuals are not clear. We sought to investigate the clinical features and the cytokine profiles of central-compartment-type CRS in our patient group. METHODS: Adult patients diagnosed with bilateral CRS were recruited, and patients who had previously undergone sinus surgery and pansinusitis (Lund-Mackay scores >23) were excluded. Central-compartment-type CRS was defined by both endoscopic and radiological features. The symptoms, inhalant allergen sensitization status, endoscopic findings, and radiological assessments were recorded and compared between patients with central-compartment-type CRS and other types of CRS. We also examined the extent of tissue eosinophilia and specific cytokine protein levels (eosinophil cationic protein [ECP], myeloperoxidase [MPO], immunoglobulin E [IgE], interleukin [IL]-4, IL-5, and IL-13) in the sinonasal tissues. RESULTS: Central-compartment-type CRS was found in 16 (23.9%) patients, and non-central-compartment-type CRS was found in 51 (76.1%) patients. Hyposmia or anosmia as the major symptom was more common in the central-compartment-type CRS group. The numbers of eosinophils in tissue and serum were significantly higher in the central-compartment-type CRS patients. The presence of allergen sensitization was not significantly different between groups. The levels of IL-5 and IL-13 were increased in middle turbinate tissues of patients with central-compartment-type CRS. CONCLUSION: Central-compartment-type CRS was associated with hyposmia or anosmia, eosinophilic subtypes, and elevated levels of IL-5 and IL-13 in middle turbinate tissues but not necessarily correlated with allergic disease in our patients.

Effect of Sleep Surgery on C-Reactive Protein Levels in Adults With Obstructive Sleep Apnea: A Meta-Analysis.

OBJECTIVES/HYPOTHESIS: To evaluate associations between sleep surgery and CRP (C-reactive protein) levels in adults with obstructive sleep apnea (OSA). STUDY DESIGN: Meta-analysis. METHODS: Two authors independently searched PubMed, Medline, EMBASE, and Cochrane review databases until July 2019. The keywords used were sleep apnea, OSA, sleep apnea syndromes, surgery, C-reactive protein (CRP), and inflammatory markers. The effects of sleep surgery on CRP levels were examined using a random-effects model. RESULTS: Nine studies with 277 patients were analyzed (mean age: 46.5 years; 92% men; mean sample size: 30.8 patients). The mean change in the apnea-hypopnea index (AHI) after surgery was significantly reduced by -21.1 (95% confidence interval [CI], -28.4 to -13.7) events/hr. Overall, sleep surgery resulted in a significant reduction of CRP levels in patients with OSA (standardized mean difference [SMD] = -0.39, 95% CI, -0.67 to -0.11). Patients with postoperative AHI reduction >20 events/hr achieved a greater reduction in CRP than those with AHI reduction <20 events/hr (SMD: -0.72 vs. -0.14, P for heterogeneity = .007). According to subgroup analysis, differences in the CRP levels after surgery were nonsignificant in the different countries (i.e., United States vs. other countries), CRP types (i.e., CRP vs. high-sensitivity CRP), surgical procedures (i.e., pharyngeal surgery vs. other surgical procedures), and follow-up period (i.e., <6 vs. >6 months). CONCLUSIONS: Sleep surgery for OSA resulted in a significant reduction of CRP levels in adults. The beneficial effect of surgery on CRP levels is greater in patients with large improvement in OSA (i.e., AHI reduction >20 events/hr) after sleep surgery. Laryngoscope, 131:1180-1187, 2021.

The clinical features of endoscopic treated isolated sphenoid sinus diseases.

BACKGROUND: Isolated sphenoid sinus disease (ISSD) is a rare clinical entity with potentially serious complications. The etiological distribution of ISSD varies among different areas and ethnicities. We aimed to investigate the clinical features of patients with endoscopic treated ISSD. METHODS: We retrospectively reviewed all patients with ISSD who had undergone endoscopic surgery between April 2013 and May 2019. The patient records were reviewed for demographic data, clinical presentations, endoscopic and imaging study findings, surgical outcomes and complications. RESULTS: A total of 37 patients with ISSD who underwent surgery were recruited. We divided patients into three groups according to etiology, including inflammatory diseases (78.4%), neoplasms (13.5%) and spontaneous cerebrospinal fluid (CSF) leaks (8.1%); fungal ball (62.2%) constituted the major cause of ISSD. Overall, the most common presenting symptom was headache or facial pain (65.5%). The endoscopic findings of bloody discharge and tumor lesions were mainly from the neoplasm group. Bony defects were more obvious on computed tomography in the neoplasm and CSF leak groups. Magnetic resonance imaging revealed a higher rate of involvement of the cavernous sinus (40.0%) and intracranial extensions (40.0%) in the neoplasm group. To summarize the surgical outcomes, the success rate was 97.1%, and the major complication rate was 5.4%. CONCLUSION: ISSD represents a variety of etiologies, mostly comprising fungal ball in our area, while there is still a considerable proportion of ISSDs attributed to neoplasm and CSF leak. Untreated ISSD can result in serious complications. We recommend early surgical intervention for all patients with ISSD.

ACE2 localizes to the respiratory cilia and is not increased by ACE inhibitors or ARBs.

The coronavirus SARS-CoV-2 is the causative agent of the ongoing severe acute respiratory disease pandemic COVID-19. Tissue and cellular tropism is one key to understanding the pathogenesis of SARS-CoV-2. We investigate the expression and subcellular localization of the SARS-CoV-2 receptor, angiotensin-converting enzyme 2 (ACE2), within the upper (nasal) and lower (pulmonary) respiratory tracts of human donors using a diverse panel of banked tissues. Here, we report our discovery that the ACE2 receptor protein robustly localizes within the motile cilia of airway epithelial cells, which likely represents the initial or early subcellular site of SARS-CoV-2 viral entry during host respiratory transmission. We further determine whether ciliary ACE2 expression in the upper airway is influenced by patient demographics, clinical characteristics, comorbidities, or medication use, and show the first mechanistic evidence that the use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARBs) does not increase susceptibility to SARS-CoV-2 infection through enhancing the expression of ciliary ACE2 receptor. These findings are crucial to our understanding of the transmission of SARS-CoV-2 for prevention and control of this virulent pathogen.

Robust ACE2 protein expression localizes to the motile cilia of the respiratory tract epithelia and is not increased by ACE inhibitors or angiotensin receptor blockers.

We investigated the expression and subcellular localization of the SARS-CoV-2 receptor, angiotensin-converting enzyme 2 (ACE2), within the upper (nasal) and lower (pulmonary) respiratory tracts of healthy human donors. We detected ACE2 protein expression within the cilia organelle of ciliated airway epithelial cells, which likely represents the initial or early subcellular site of SARS-CoV-2 viral entry during respiratory transmission. We further determined whether ACE2 expression in the cilia of upper respiratory cells was influenced by patient demographics, clinical characteristics, co-morbidities, or medication use, and found no evidence that the use of angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARBs) increases ACE2 protein expression.

Association of cumulative surgeon volume and risk of complications in adult uvulopalatopharyngoplasty: a population-based study in Taiwan.

STUDY OBJECTIVES: Patients with obstructive sleep apnea undergoing upper airway surgery are known to have an increased perioperative risk, however, the effect of surgeon volume on this risk is largely unknown. We compared the 30-day readmission, bleeding, and mortality rates in adult patients with obstructive sleep apnea undergoing uvulopalatopharyngoplasty by cumulative surgeon volume. The objective of this study is to compare the risks of complications among different cumulative surgeon volume groups in adult patients undergoing uvulopalatopharyngoplasty and multilevel surgery. METHODS: In this retrospective study, data of all adult inpatients (aged older than 18 years) who underwent uvulopalatopharyngoplasty in Taiwan between 2000 and 2012 were identified from the National Health Insurance Research Database and then analyzed. Using mixed-effect logistic regression, we compared the risks of major complications in patients undergoing uvulopalatopharyngoplasty alone, uvulopalatopharyngoplasty with nasal surgery, and uvulopalatopharyngoplasty with tongue or hypopharyngeal surgery according to groups of cumulative surgeon volume (divided into four quartiles). RESULTS: A total of 36,483 adults were identified (mean age, 38.6 years; 73.7% men). When quartile 4 was used as reference, very low surgeon volume (quartile 1) was associated with higher risks of readmission within 30 days (adjusted odds ratio [aOR] 1.35, 95% confidence interval [CI] 1.17-1.57, P < .001), in-hospital death (aOR, 6.14, 95% CI 1.33-28.27, P = .020), and 30-day mortality (aOR, 4.90, 95% CI 1.83-13.09, P = .002). CONCLUSIONS: Higher complication rates in uvulopalatopharyngoplasty appear to be associated with very low cumulative surgeon volume.