Cold exposure impairs extracellular vesicle swarm-mediated nasal antiviral immunity.

BACKGROUND: The human upper respiratory tract is the first site of contact for inhaled respiratory viruses and elaborates an array of innate immune responses. Seasonal variation in respiratory viral infections and the importance of ambient temperature in modulating immune responses to infections have been well recognized; however, the underlying biological mechanisms remain understudied. OBJECTIVE: We investigated the role of nasal epithelium-derived extracellular vesicles (EVs) in innate Toll-like receptor 3 (TLR3)-dependent antiviral immunity. METHODS: We evaluated the secretion and composition of nasal epithelial EVs after TLR3 stimulation in human autologous cells and fresh human nasal mucosal surgical specimens. We also explored the antiviral activity and mechanisms of TLR3-stimulated EVs against respiratory viruses as well as the effect of cool ambient temperature on TLR3-dependent antiviral immunity. RESULTS: We found that polyinosinic:polycytidylic acid, aka poly(I:C), exposure induced a swarm-like increase in the secretion of nasal epithelial EVs via the TLR3 signaling. EVs participated in TLR3-dependent antiviral immunity, protecting the host from viral infections through both EV-mediated functional delivery of miR-17 and direct virion neutralization after binding to virus ligands via surface receptors, including LDLR and ICAM-1. These potent antiviral immune defense functions mediated by TLR3-stimulated EVs were impaired by cold exposure via a decrease in total EV secretion as well as diminished microRNA packaging and antiviral binding affinity of individual EV. CONCLUSION: TLR3-dependent nasal epithelial EVs exhibit multiple innate antiviral mechanisms to suppress respiratory viral infections. Furthermore, our study provides a direct quantitative mechanistic explanation for seasonal variation in upper respiratory tract infection prevalence.

Cystatin SN is a potent upstream initiator of epithelial-derived type 2 inflammation in chronic rhinosinusitis.

BACKGROUND: Cystatin SN (CST1) and cystatin SA (CST2) are cysteine protease inhibitors that protect against allergen, viral, and bacterial proteases. Cystatins are overexpressed in the setting of allergic rhinitis and chronic rhinosinusitis with nasal polyps (CRSwNP); however, their role in promoting type 2 inflammation remains poorly characterized. OBJECTIVE: The purpose of this study was to use integrated poly-omics and a murine exposure model to explore the link between cystatin overexpression in CRSwNP and type 2 inflammation. METHODS: In this institutional review board- and institutional animal care and use committee-approved study, we compared tissue, exosome, and mucus CST1 and CST2 between CRSwNP and controls (n = 10 per group) by using matched whole exome sequencing, transcriptomic, proteomic, posttranslational modification, histologic, functional, and bioinformatic analyses. C57/BL6 mice were dosed with 3.9 µg/mL of CST1 or PBS intranasally for 5 to 18 days in the presence or absence of epithelial ABCB1a knockdown. Inflammatory cytokines were quantified by using Quansys multiplex assays or ELISAs. RESULTS: Of the 1305 proteins quantified, CST1 and CST2 were among the most overexpressed protease inhibitors in tissue, exosome, and mucus samples; they were localized to the epithelial layer. Multiple posttranslational modifications were identified in the polyp tissue. Exosomal CST1 and CST2 were strongly and significantly correlated with eosinophils and Lund-Mackay scores. Murine type 2 cytokine secretion and TH2 cell infiltration increased in a time-dependent manner following CST1 exposure and was abrogated by epithelial knockdown of ABCB1a, a regulator of epithelial cytokine secretion. CONCLUSION: CST1 is a potent upstream initiator of epithelial-derived type 2 inflammation in CRSwNP. Therapeutic strategies targeting CST activity and its associated posttranslational modifications deserve further interrogation.

Protease-activated receptor 2 activates airway apical membrane chloride permeability and increases ciliary beating.

Mucociliary clearance, driven by the engine of ciliary beating, is the primary physical airway defense against inhaled pathogens and irritants. A better understanding of the regulation of ciliary beating and mucociliary transport is necessary for identifying new receptor targets to stimulate improved clearance in airway diseases, such as cystic fibrosis and chronic rhinosinusitis. In this study, we examined the protease-activated receptor (PAR)-2, a GPCR previously shown to regulate airway cell cytokine and mucus secretion, and transepithelial Cl- current. PAR-2 is activated by proteases secreted by airway neutrophils and pathogens. We cultured various airway cell lines, primary human and mouse sinonasal cells, and human bronchial cells at air-liquid interface and examined them using molecular biology, biochemistry, and live-cell imaging. We found that PAR-2 is expressed basolaterally, where it stimulates both intracellular Ca2+ release and Ca2+ influx, which activates low-level nitric oxide production, increases apical membrane Cl- permeability ∼3-5-fold, and increases ciliary beating ∼20-50%. No molecular or functional evidence of PAR-4 was observed. These data suggest a novel and previously overlooked role of PAR-2 in airway physiology, adding to our understanding of the role of this receptor in airway Ca2+ signaling and innate immunity.-McMahon, D. B., Workman, A. D., Kohanski, M. A., Carey, R. M., Freund, J. R., Hariri, B. M., Chen, B., Doghramji, L. J., Adappa, N. D., Palmer, J. N., Kennedy, D. W., Lee, R. J. Protease-activated receptor 2 activates airway apical membrane chloride permeability and increases ciliary beating.

Solitary chemosensory cells are a primary epithelial source of IL-25 in patients with chronic rhinosinusitis with nasal polyps.

BACKGROUND: IL-25 can function as an early signal for the respiratory type 2 response characteristic of allergic asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). In the mouse gut, tuft cells are the epithelial source of IL-25. However, the source of human airway epithelial IL-25 has remained elusive. OBJECTIVE: In this study we sought to determine whether the solitary chemosensory cell (SCC) is the predominant source of IL-25 in the sinonasal epithelium. METHOD: Flow cytometry and immunofluorescence for SCCs and IL-25 were used to interrogate polyp and turbinate tissue from patients with CRSwNP. Mucus was collected during acute inflammatory exacerbations from patients with CRSwNP or chronic rhinosinusitis without nasal polyps and IL-25 levels determined by using ELISA. Lastly, sinonasal epithelial cultures derived from polyp and turbinate tissue were stimulated with IL-13 and analyzed for SCC proliferation and IL-25 production. RESULTS: This study demonstrates that a discrete cell type, likely an SCC, characterized by expression of the taste-associated G protein gustducin and the intestinal tuft cell marker doublecortin-like kinase 1, is the predominant source of IL-25 in the human upper airway. Additionally, we show that patients with CRSwNP have increased numbers of SCCs in nasal polyp tissue and that in vitro IL-13 exposure both increased proliferation and induced apical secretion of IL-25 into the mucosal layer. CONCLUSIONS: Inflammatory sinus polyps but not adjacent turbinate tissue show expansion of the SCC population, which is the source of epithelial IL-25.

Increasing Medical Student Exposure to IR through Integration of IR into the Gross Anatomy Course.

PURPOSE: To compare medical student knowledge of and interest in interventional radiology (IR) before and after the integration of an IR lecture series within the gross anatomy course. MATERIALS AND METHODS: Four elective IR lectures were scheduled to coincide with the relevant anatomy dissection curriculum. Anonymous surveys were distributed to 146 students before and after the lectures regarding students' knowledge of and interest in IR, responsibilities of an IR physician, and IR training pathways. Those who did not attend served as controls. RESULTS: Response rates were 67% (n = 98) in the prelecture group, 55% (n = 22) in the group who attended the lecture, and 28% (n = 30) in the control group. A total of 73% of the prelecture group reported little knowledge of IR compared with other specialties. This decreased to 27% in those who attended the lecture (P < .001). A total of 32% of those who attended believed they had more knowledge of IR than any other specialty, compared with 7% of controls (P value not significant) and 2% of the prelecture group (P < .001). Those in attendance could name a significantly greater number of IR procedures (mean, 1.82) than the prelecture group (mean, 0.57; P < .001). A total of 64% of those who attended would consider a career in IR, compared with 24% in the prelecture group and 33% in the control group (P < .05). A total of 68% of those who attended had knowledge of the IR residency, compared with 5% in the prelecture group and 33% in the control group (P < .05). CONCLUSIONS: Integration of IR education into the gross anatomy course proved to be a highly effective way of teaching preclinical students about IR and generating interest in the field.

The timing of retears after arthroscopic rotator cuff repair.

BACKGROUND: Little is known about the time dependence of the failure rate of surgically repaired rotator cuffs. Retears are significant, as they are common and may lead to less satisfactory outcomes and additional operations. Their timing is critical foundational information for understanding failure mechanisms. However, this remains unclear. Currently, there exist a number of studies that have reported retear rates at specific time points. Combining data from these publications can reveal when cuffs retear, which will help inform expectations and guidelines for progression of activity after surgery. METHODS: PubMed, Medline, and Embase were searched for studies relating to rotator cuff repair. Abstracts and articles were evaluated on the basis of predefined inclusion and exclusion criteria. Data were extracted from those publications that satisfied all requirements, and regression analysis was performed. RESULTS: Thirteen articles were included in the final meta-analysis. Retear rates for medium tears increased for approximately 15 months and leveled off at approximately 20%. Retear rates for large tears progressed steadily for about 12 months and approached an upper limit of approximately 40%. Retear rates for massive tears ranged from 20% to 60%, but the distribution of retear rate over time for these cuff tears is not clear from these data. CONCLUSION: Retear rates for medium and large tears generally increase until at least 10-15 months after surgery, after which they are likely to level off. Retear rates for massive tears are variable and may follow a time course different from that of other tear sizes. Retear rates depend on size of the original tear.

The Role of Bitter and Sweet Taste Receptors in Upper Airway Immunity.

Over the past several years, taste receptors have emerged as key players in the regulation of innate immune defenses in the mammalian respiratory tract. Several cell types in the airway, including ciliated epithelial cells, solitary chemosensory cells, and bronchial smooth muscle cells, all display chemoresponsive properties that utilize taste receptors. A variety of bitter products secreted by microbes are detected with resultant downstream inflammation, increased mucous clearance, antimicrobial peptide secretion, and direct bacterial killing. Genetic variation of bitter taste receptors also appears to play a role in the susceptibility to infection in respiratory disease states, including that of chronic rhinosinusitis. Ongoing taste receptor research may yield new therapeutics that harness innate immune defenses in the respiratory tract and may offer alternatives to antibiotic treatment. The present review discusses taste receptor-protective responses and analyzes the role these receptors play in mediating airway immune function.

Modeling transformations of neurodevelopmental sequences across mammalian species.

A general model of neural development is derived to fit 18 mammalian species, including humans, macaques, several rodent species, and six metatherian (marsupial) mammals. The goal of this work is to describe heterochronic changes in brain evolution within its basic developmental allometry, and provide an empirical basis to recognize equivalent maturational states across animals. The empirical data generating the model comprises 271 developmental events, including measures of initial neurogenesis, axon extension, establishment, and refinement of connectivity, as well as later events such as myelin formation, growth of brain volume, and early behavioral milestones, to the third year of human postnatal life. The progress of neural events across species is sufficiently predictable that a single model can be used to predict the timing of all events in all species, with a correlation of modeled values to empirical data of 0.9929. Each species' rate of progress through the event scale, described by a regression equation predicting duration of development in days, is highly correlated with adult brain size. Neural heterochrony can be seen in selective delay of retinogenesis in the cat, associated with greater numbers of rods in its retina, and delay of corticogenesis in all species but rodents and the rabbit, associated with relatively larger cortices in species with delay. Unexpectedly, precocial mammals (those unusually mature at birth) delay the onset of first neurogenesis but then progress rapidly through remaining developmental events.

Complications of Oral Corticosteroid Use in Otolaryngology.

OBJECTIVE: Oral corticosteroids (OCS) are frequently prescribed by otolaryngologists. However, there are limited quantitative data on OCS-related adverse events (AEs) in otolaryngology. We sought to quantify OCS-related AEs in otolaryngology. METHODS: All outpatient otolaryngology encounters in our healthcare system (2018-2023) at which an OCS was prescribed were identified via the electronic medical record. The diagnoses indicating OCS were categorized as sinonasal, otologic, pharyngo-laryngeal, and other. The medical record was subsequently examined to assess for OCS AEs during the 21-day period following the prescription. OCS AEs were grouped into (1) gastrointestinal, (2) metabolic, (3) bone/muscle, (4) ophthalmologic, and/or (5) psychiatric complications. The frequency and types of OCS related AEs were determined. RESULTS: A total of 20 746 otolaryngology encounters with OCS prescribed were examined. Seventy OCS courses had 1 or more AEs, implying a number needed to harm of 296.4 (240.2-386.8). There were 83 total OCS-related AEs, yielding an AE incidence rate of 4.0:1000 (95% CI, 3.0-5.0:1000) OCS prescriptions. The mean age of subjects with AEs (61.5 years) was significantly higher than those without (50.3 years; P < .001). Forty-seven (56.6%) of the complications were metabolic, with hyperglycemia and hypokalemia the most common, followed by gastrointestinal (26.5%), ophthalmologic (3.6%), psychiatric (2.4%), and musculoskeletal (2.4%). CONCLUSION: AEs related to OCS prescribed by otolaryngologists occur at a rate of once per 296 courses of treatment and older populations may be at increased risk for AEs. Otolaryngologists should balance AE rates against anticipated benefits of steroid therapy. LEVEL OF EVIDENCE: 3.

Aerosolized Particulate Matter and Blunting of Ciliary Dynamic Responses: Implications for Veterans and Active Duty Military in Southwest Asia.

INTRODUCTION: Respiratory diseases such as chronic rhinosinusitis and asthma are observed at increased rates in active duty and veteran military members, and they are especially prevalent in individuals who have been deployed in Southwest Asia during Operation Iraqi Freedom and Operation Enduring Freedom. Particulate matter, specifically the fine-grain desert sand found in the Middle East, may be a key source of this pathology because of deleterious effects on mucociliary clearance. MATERIALS AND METHODS: With IRB approval, human sinonasal tissue was grown at an air-liquid interface and cultures were exposed to different types and sizes of particulate matter, including sand from Afghanistan and Kuwait. Ciliary dynamic responses to mechanical stimulation and ATP application were assessed following particulate exposure. RESULTS: Particle size of the commercial sand was substantially larger than that of the sand of Afghan or Kuwaiti origin. Following exposure to particulate matter, normal dynamic ciliary responses to mechanical stimulation and ATP application were significantly decreased (P < .01), with corresponding decreases in ATP-induced calcium flux (P < .05). These changes were partially reversible with apical washing after a 16-h period of exposure. After 36 h of exposure to Middle Eastern sand, ciliary responses to purinergic stimulation were completely abolished. CONCLUSIONS: There is a neutralization of the dynamic ciliary response following chronic particulate matter exposure, similar to ciliary pathologies observed in patients with chronic rhinosinusitis. Aerosolized particulate matter endured by military personnel in the Southwest Asia may cause dysfunctional mucociliary clearance; these data help to explain the increased prevalence of respiratory pathology in individuals who are or have been deployed in this region.

Adverse events associated with budesonide nasal irrigation reported to the US Food and Drug Administration: 2007 to 2022.

KEYPOINTS: Between 2007 and 2022, the FDA received 119 US-based reports mentioning budesonide nasal irrigation. Most reports were submitted by patients and alerted FDA to off-label usage of budesonide. Notable adverse events reported to the FDA included headache, dyspnea, and blurred vision.

Assessing adequacy of surgical extent in CRSwNP: The Completion of Surgery Index.

BACKGROUND: Endoscopic sinus surgery (ESS) maximized for topical steroid irrigations is highly effective for polyp disease. As extent and completeness of ESS varies widely by situation and practitioner, it is important to understand when revision surgery is appropriate, particularly in the era of biologic treatments. METHODS: A Completion of Surgery Index (CoSI) was developed to assess operative changes in polyp patients using pre- and postoperative computed tomography scans. The CoSI was then applied and tested in a cohort of consecutive chronic rhinosinusitis with nasal polyps (CRSwNP) patients, and examined within the context of quality-of-life improvements. RESULTS: The CoSI assesses surgical extent on a scale of 0-100, with 100 representing the highest possible degree of surgical completeness. Among 100 consecutive CRSwNP patients undergoing ESS in 2021 with postoperative topical steroid irrigations, including 75 revision surgeries, SNOT-22 scores improved at 6 months postoperatively, with durable and consistent improvement at 24 months (p < 0.001). Preoperative CoSI scores in revision surgery patients were 49.4 ± 26.0, improving to 91.0 ± 8.1 postoperatively. SNOT-22 scores for primary ESS patients and patients with a preoperative CoSI score of less than 70 improved by 26.4 and 28.1 points, respectively, in contrast to patients with a preoperative CoSI of 70 or greater (14.1 points, p = 0.029). CONCLUSIONS: It is important to define extent of surgery in CRSwNP to stratify postsurgical patients based on likelihood to benefit from revision surgery or alternative medications. The CoSI can be utilized to identify patients who are likely to improve significantly with revision surgical intervention.

Utilizing Histopathology to Predict Success with Macrolide Therapy in CRS Patients.

There is currently interest regarding CRSsNP patients with refractory symptomatology following functional endoscopic sinus surgery, and which of these patients can derive benefit from low-dose macrolide therapy. In the present study, we analyze a cohort of over fifty CRSsNP patients on macrolide therapy; structured histopathological findings at the time of surgery were analyzed against the success of macrolide treatment. Independently, fibrosis, absence of squamous metaplasia, absence of eosinophilia, presence of neutrophilic infiltrate, and lymphoplasmocytic predominance were all associated with objective success of macrolide treatment; these findings may allow clinicians to more appropriately select patients for this therapy.

Availability and Pricing of Drugs Prescribed by Otolaryngologists Through a Direct-to-Consumer Pharmacy: Medicare Savings Implications.

High prescription drug prices can financially strain patients and insurers, with substantial clinical repercussions. In recent years, direct-to-consumer (DTC) pharmacies have emerged as potentially lower-cost alternatives for patients to fill prescriptions. We evaluated whether drugs commonly prescribed by otolaryngologists were available at a national DTC pharmacy (Mark Cuban Cost Plus Drug Company [MCCPDC]) and estimated potential Medicare savings from DTC pricing. We identified drugs and prices paid by Medicare Part D plans using the 2021 Drug Spending Dashboard. Our analysis included 16 generic drugs within the MCCPDC formulary, which offered lower prices for 14 (87.5%) drugs. If plans had secured MCCPDC pricing for all 16 drugs, Medicare patients and plans would have saved $2.9 billion (relative reduction: 62.3%) in 2021. Estimated total savings were greatest for budesonide-formoterol ($1.9 billion), dexlansoprazole ($464.6 million), and levothyroxine ($327.4 million). Otolaryngologists and insurers may consider utilizing DTC pharmacies with lower drug prices, though patients may face challenges projecting out-of-pocket costs across pharmacies, medications, benefit phases, and formulary tiers.

Utility of a LangChain and OpenAI GPT-powered chatbot based on the international consensus statement on allergy and rhinology: Rhinosinusitis.

KEY POINTS: We created a LangChain/OpenAI API-powered chatbot based solely on International Consensus Statement of Allergy and Rhinology: Rhinosinusitis (ICAR-RS). The ICAR-RS chatbot is able to provide direct and actionable recommendations. Utilization of consensus statements provides an opportunity for AI applications in healthcare.

The Inflation Reduction Act: Implications for Medicare spending and access to biologic therapies for chronic rhinosinusitis with nasal polyposis and asthma.

KEY POINTS: In 2021, Medicare spending on biologics was $926 million in Part B (FFS) and $1.3 billion in Part D (FFS/MA). Between 2017 and 2021, annual Medicare spending on biologics increased by approximately 200%. Between 2023 and 2025, Medicare Part D OOP costs for biologics will decrease by an estimated 50%-60%.

Generic competition and prices for azelastine-fluticasone nasal spray.

KEY POINTS: The original manufacturer of azelastine‒fluticasone (AZ‒FL) prevented generic availability until 2020 via patent enforcement. Following generic availability of AZ‒FL, Medicare utilization increased and spending decreased. Retail prices for generic AZ‒FL remain high due to markup by manufacturers and pharmacies.

Time is money: An analysis of cost drivers in ambulatory sinus surgery.

BACKGROUND: Functional endoscopic sinus surgery (FESS) is one of the most commonly performed otolaryngologic procedures and is associated with significant cost variability. METHODS: We performed a retrospective analysis of all inflammatory sinus surgeries at a single tertiary care medical center from July 2021 to July 2023. The electronic medical record was reviewed for patient factors and cost variables for each procedure, and multivariable analysis was performed. RESULTS: A total of 221 patients were included in analysis with a mean age of 48.2 years. There was a 44.8% incidence (n = 99) of nasal polyps and 31.2% (n = 69) of cases were revision surgeries. The average total cost for the surgical encounter was $8960.31 (standard deviation $1967.97). Operating room time represented $4912.46 (54.8% of all costs), while average operating room supply costs were $1296.06 (14.5%) and recovery room costs were $919.48 (10.3%). Total costs were significantly associated with length of surgery ($7.83/min, p = 0.04), in addition to presence of nasal polyps ($531.96, p = 0.04). There was no significant association between total costs and the remaining clinical and demographic factors. CONCLUSIONS: Costs associated with ambulatory FESS for inflammatory sinus disease vary across patients and this cost variability is predominantly driven by time efficiency within the operating room, as well as supply utilization and nasal polyposis to a lesser degree. As a result, operating room efficiency represents a primary target for cost-related interventions. Additionally, our data provide a framework for surgeons and hospitals to make evidence-based decisions on intraoperative equipment in a tradeoff between efficiency and supply costs. Our findings indicate that an approach focused on streamlining efficiency across the entire ambulatory surgery encounter will have the greatest impact on reducing healthcare expenses for both the patient and the health system.

Longer-term surveillance imaging and endoscopy critical for majority of patients in detection of sinonasal malignancy recurrence.

BACKGROUND: Sinonasal malignancy surveillance paradigms are often based on Head and Neck National Comprehensive Cancer Network guidelines, which do not recommend standard surveillance imaging beyond 6 months without concerning symptomatology or physical examination findings. METHODS: This was a retrospective analysis of all patients who underwent resection of sinonasal malignancy at a tertiary care center over a 20-year period from 2000 to 2020, with an ensuing surveillance period demonstrating recurrence. RESULTS: Fifty-two patients with sinonasal malignancy recurrence were included, with an average time to recurrence of 30.9 months and a follow-up period of over 60 months. Recurrence was diagnosed by routine imaging or endoscopy in asymptomatic patients in a majority (60%) of cases, while the remaining minority of diagnoses followed new symptomatology. Asymptomatic recurrence was associated with perineural spread of tumor at initial resection (p = 0.025), but not with age (p = 0.85) or stage at diagnosis (p = 0.68). Expectedly, positron emission tomography/computed tomography (CT) more often detected regional or distant recurrence, while structural imaging (CT/magnetic resonance imaging) demonstrated more frequent detection of recurrence in those with perineural spread of tumor (p = 0.01). CONCLUSIONS: Our findings support high rates of asymptomatic recurrence in sinonasal malignancy, with the majority of recurrences diagnosed by routine endoscopy or imaging. Tailored and extended surveillance guidelines are necessary relative to those utilized for other head and neck mucosal cancers, and are especially appropriate when features such as perineural spread are present.

Clinically meaningful changes in efficacy outcomes in chronic rhinosinusitis with nasal polyposis.

PURPOSE OF REVIEW: Chronic rhinosinusitis with nasal polyps (CRSwNP) carries a high disease burden, and many studies have been done investigating the efficacy of various medical and surgical therapies. However, outcome metrics have varied across these studies, making it difficult to compare therapeutic efficacy on a large scale. In this article, we discuss various outcome metrics used across prior studies as well as the relationship between these measures. RECENT FINDINGS: Outcome metrics in CRSwNP studies include both clinically assessed and patient-reported outcome measures (PROMs). The former includes olfaction testing, scoring systems based on imaging and endoscopic evaluation, and histopathological and immunohistochemical evaluation of sinus tissue, and the latter includes quality-of-life instruments, symptom severity scales, and disease-control instruments. Recent studies evaluating the efficacy of new biologics have used a combination of both types of metrics. SUMMARY: Both clinical metrics and patient-reported outcomes provide utility in evaluating disease severity and control in patients with CRSwNP, although there are nuances when comparing therapies in this population as patients with CRSwNP are heterogeneous and may have symptoms across several domains. However, PROMs in conjunction with clinical metrics provide useful information to assess patient symptoms and response to interventions.