Protocol for postmortem bedside endoscopic procedure to sample human respiratory and olfactory cleft mucosa, olfactory bulbs, and frontal lobe

We present a protocol for the rapid postmortem bedside procurement of selected tissue samples using an endoscopic endonasal surgical technique that we adapted from skull base surgery. We describe steps for the postmortem collection of blood, cerebrospinal fluid, a nasopharyngeal swab, and tissue samples; the clean-up procedure; and the initial processing and storage of the samples. This protocol was validated with tissue samples procured postmortem from COVID-19 patients and can be applied in another emerging infectious disease. For complete details on the use and execution of this protocol, please refer to Khan et al. (2021)1 and Khan et al. (2022).2.

Leukocyte- and platelet-rich fibrin in cranial surgery: a single-blinded, prospective, randomized controlled noninferiority trial

OBJECTIVE

CSF leakage is a major complication after cranial surgery, and although fibrin sealants are widely used for reinforcing dural closure, concerns exist regarding their safety, efficacy, and cost. Leukocyte- and platelet-rich fibrin (L-PRF), an autologous platelet concentrate, is readily available and inexpensive, making it a cost-effective alternative for commercially available fibrin sealants. This study aimed to demonstrate the noninferiority of L-PRF compared with commercially available fibrin sealants in preventing postoperative CSF leakage in supra- and infratentorial cranial surgery, with secondary outcomes focused on CSF leakage risk factors and adverse events.

METHODS

In a single-blinded, prospective, randomized controlled interventional trial conducted at a neurosurgery department of a tertiary care center (UZ Leuven, Belgium), patients undergoing elective cranial neurosurgery were randomly assigned to receive either L-PRF (active treatment) or commercially available fibrin sealants (control) for dural closure in a 1:1 ratio.

RESULTS

Among 350 included patients, 328 were analyzed for the primary endpoint (44.5% male, mean age 52.3 ± 15.1 years). Six patients (5 in the control group, 1 in the L-PRF group) presented with CSF leakage requiring any intervention (relative risk [RR] 0.20, one-sided 95% CI -∞ to 1.02, p = 0.11), confirming noninferiority. Of these 6 patients, 1 (in the control group) presented with CSF leakage requiring revision surgery. No risk factors for reconstruction failure in combination with L-PRF were identified. RRs for adverse events such as infection (0.72, 95% CI -∞ to 1.96) and meningitis (0.36, 95% CI -∞ to 1.25) favored L-PRF treatment, although L-PRF treatment showed slightly more bleeding events (1.44, 95% CI -∞ to 4.66).

CONCLUSIONS

Dural reinforcement with L-PRF proved noninferior to commercially available fibrin sealants, with no safety issues. Introducing L-PRF to standard clinical practice could result in important cost savings due to accessibility and lower cost. Clinical trial registration no.: NCT03812120 (ClinicalTrials.gov).

Stability of magistral phage preparations before therapeutic application in patients with chronic rhinosinusitis, sepsis, pulmonary, and musculoskeletal infections

IMPORTANCE

As antimicrobial resistance becomes more prevalent, the application of (bacterio)phage therapy as an alternative treatment for difficult-to-treat infections is (re)gaining popularity. Over the past decade, numerous promising case reports and series have been published demonstrating the therapeutic potential of phage therapy. However, important questions remain regarding the optimal treatment protocol and, unlike for medicinal products, there are currently no predefined quality standards for the stability of phage preparations. Phage titers can be influenced by several factors which could lead to reduced titers after preparation and storage and, ultimately, subtherapeutic applications. Determining the stability of different phages in different recipients according to the route of administration is therefore one of the first important steps in establishing a standardized protocol for phage therapy.

Evaluation of skin prick location on the forearm using a novel skin prick automated test device

Background

The skin prick test (SPT) is the gold standard for identifying allergic sensitization in individuals suspected of having an inhalant allergy. Recently, it was demonstrated that SPT using a novel skin prick automated test (SPAT) device showed increased reproducibility and tolerability compared to the conventional SPT, among other benefits.

Objective

This study aimed to evaluate prick location bias using the novel SPAT device.

Methods

A total of 118 volunteers were enrolled in this study and underwent SPATs with histamine (nine pricks) and glycerol control (one prick) solutions on the volar side of their forearms. Imaging of the skin reactions was performed using the SPAT device, and the physician determined the longest wheal diameter by visually inspecting the images using a web interface. Prick location bias was assessed along the medial vs. lateral and proximal vs. distal axes of the forearm.

Results

In total, 944 histamine pricks were analyzed. Four medial and four lateral histamine pricks were grouped, and wheal sizes were compared. The longest wheal diameters were not significantly different between the medial and lateral prick locations (p = 0.41). Furthermore, the pricks were grouped by two based on their position on the proximal-distal axis of the forearm. No significant difference was observed among the four groups of analyzed prick locations (p = 0.73).

Conclusion

The prick location on the volar side of the forearm did not influence wheal size in SPAT-pricked individuals.

Upper Airway Disease in Adults with Cystic Fibrosis in the Era of CFTR Modulators

OBJECTIVES

Chronic rhinosinusitis (CRS) is prevalent in people with cystic fibrosis (PwCF) and is often refractory to treatments. Uncontrolled CRS might negatively impact the lower airways and the quality of life. The aim of this study is to evaluate the burden of cystic fibrosis (CF)-related CRS in the era of CF transmembrane conductance regulator (CFTR) modulators.

METHODS

Adult PwCF were asked to fill in a questionnaire on sinonasal complaints, they underwent a nasal endoscopy, bacteriological sampling, and a CT scan. Afterwards, these outcome measures were compared between patients treated with and without modulators.

RESULTS

In the 122 included patients, CRS was present in 83%. CFTR modulators were prescribed in 48% of the patients, with a median of 10 months since the start of the treatment. Subjectively, the median SNOT-22 score was 16/110. Objectively, a median Lund-Kennedy score of 6/12 and modified Lund-Mackay score of 10/24 were observed. No correlation could be found between SNOT-22 score and other outcome measures including endoscopy and radiology. Altogether, 21% of the patients had controlled disease. When comparing patients treated with and without modulators, significantly lower CT scores (p = 0.0018) and less bacterial colonization (p = 0.0082) were observed in patients receiving modulators.

CONCLUSION

CF-CRS is highly prevalent in our cohort and only the minority of PwCF has a well-controlled disease. A multidisciplinary ENT-pneumology clinic would be beneficial, as there is a high discrepancy between patient-reported symptoms and the extent of the disease. CFTR modulators are promising, as lower CT scores and less bacterial colonization were observed in the modulator group.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 133:2898-2909, 2023.

Leukocyte- and platelet-rich fibrin in endoscopic endonasal skull base reconstruction: study protocol for a multicenter prospective, parallel-group, single-blinded randomized controlled non-inferiority trial

BACKGROUND

Recent advances in endoscopic endonasal transsphenoidal approaches (EETA) for skull base lesions have resulted in a significant increase in extent and complexity of skull base defects, demanding more elaborate and novel reconstruction techniques to prevent cerebrospinal fluid (CSF) leakage and to improve healing. Currently, commercially available fibrin sealants are often used to reinforce the skull base reconstruction. However, problems have been reported regarding hypersensitivity reactions, efficacy, and costs. This trial aims to investigate autologous leukocyte- and platelet-rich fibrin (L-PRF) membranes as an alternative for commercially available fibrin glues in EETA-related skull base reconstruction reinforcement.

METHODS/DESIGN

This multicenter, prospective randomized controlled trial aims to demonstrate non-inferiority of L-PRF membranes compared to commercially available fibrin sealants in EETA cases (1) without intra-operative CSF-leak as dural or sellar floor closure reinforcement and (2) in EETA cases with intra-operative CSF-leak (or very large defects) in which a classic multilayer reconstruction has been made, as an additional sealing. The trial includes patients undergoing EETA in three different centers in Belgium. Patients are randomized in a 1:1 fashion comparing L-PRF with commercially available fibrin sealants. The primary endpoint is postoperative CSF leakage. Secondary endpoints are identification of risk factors for reconstruction failure, assessment of rhinological symptoms, and interference with postoperative imaging. Additionally, a cost-effectiveness analysis is performed.

DISCUSSION

With this trial, we will evaluate the safety and efficacy of L-PRF compared to commercially available fibrin sealants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03910374. Registered on 10 April 2019.

Impact of environmental nitrogen pollution on pollen allergy: A scoping review

The current rise in the prevalence of allergies to aeroallergens is incompletely understood and attributed to interactions with environmental changes and lifestyle changes. Environmental nitrogen pollution might be a potential driver of this increasing prevalence. While the ecological impact of excessive nitrogen pollution has been widely studied and is relatively well understood, its indirect effect on human allergies is not well documented. Nitrogen pollution can affect the environment in various ways, including air, soil, and water. We aim to provide a literature overview of the nitrogen-driven impact on plant communities, plant productivity, and pollen properties and how they lead to changes in allergy burden. We included original articles investigating the associations between nitrogen pollution, pollen, and allergy, published in international peer-reviewed journals between 2001 and 2022. Our scoping review found that the majority of studies focus on atmospheric nitrogen pollution and its impact on pollen and pollen allergens, causing allergy symptoms. These studies often examine the impact of multiple atmospheric pollutants and not just nitrogen, making it difficult to determine the specific impact of nitrogen pollution. There is some evidence that atmospheric nitrogen pollution affects pollen allergy by increasing atmospheric pollen levels, altering pollen structure, altering allergen structure and release, and causing increased allergenic reactivity. Limited research has been conducted on the impact of soil and aqueous nitrogen pollution on pollen allergenic reactivity. Further research is needed to fill the current knowledge gap about the impact of nitrogen pollution on pollens and their related allergic disease burden.

Leukocyte- and platelet-rich fibrin in cranial surgery: study protocol for a prospective, parallel-group, single-blinded randomized controlled non-inferiority trial {1}

BACKGROUND

CSF leakage is a major complication after cranial surgery, thus, adequate dural closure must be performed. Commercially available fibrin sealants are currently considered the gold standard for dural closure, but problems have been reported regarding safety, efficacy, and costs. This trial aims to investigate autologous leukocyte- and platelet-rich fibrin (L-PRF) as an alternative to commercially available fibrin sealants.

METHODS/DESIGN

This single-blinded, prospective randomized controlled interventional trial aims to demonstrate the non-inferiority of L-PRF compared to commercially available fibrin sealants for dural closure. This trial will include patients undergoing cranial neurosurgery (supratentorial and infratentorial) with intentional opening of the dura. Patients are randomized in a 1:1 fashion comparing L-PRF to commercially available fibrin sealants. The primary endpoint is postoperative CSF leakage within 12 weeks after surgery. Secondary endpoints are complications such as bleeding or wound infections. Additionally, a cost-effectiveness analysis is performed.

DISCUSSION

With this trial, we will evaluate the safety and efficiency of L-PRF compared to commercially available fibrin sealants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03812120. Registered on 22 January 2019.

Chronic Rhinosinusitis Outcome Registry (CHRINOSOR): Establishment of an International Outcome Registry Driven by mHealth Technology

BACKGROUND

Real-world evidence (RWE) is a valuable instrument to better understand the patient journey and effectiveness of therapies. RWE on the prevalence of uncontrolled chronic rhinosinusitis (CRS) and CRS natural course of disease across Europe is scarce. In addition, there is limited RWE that enables comparison of the effectiveness of marketed therapies including topical or systemic corticosteroids, sinus surgery, or biologics.

OBJECTIVE

To establish an international CHRonic rhINOSinusitis Outcome Registry (CHRINOSOR) based on real-world data collection enabled by mobile health technology.

METHODOLOGY

A digital platform, Galenus Health, supporting patients and physicians in the management of chronic respiratory diseases, is used to collect data on patient profile, disease history, patient outcomes, and a set of relevant clinical outcomes. Adult patients with a diagnosis of CRS are eligible for inclusion.

RESULTS

A collaborative scientific network of 17 university ear-nose-throat (ENT) clinics from 10 European countries has been established with the aim to collect real-world data in a longitudinal and standardized manner. The Galenus Health digital platform is currently being implemented in these ENT clinics taking into account legal, privacy, and data security aspects. Up to 300 patients have already been included.

CONCLUSIONS

CHRINOSOR is a collaborative effort that aims at improving our understanding of CRS, its comorbidities, and the effectiveness of its treatments. Ultimately, these insights will guide us as scientific community to develop future care pathways informed by RWE.

Anatomical barriers against SARS-CoV-2 neuroinvasion at vulnerable interfaces visualized in deceased COVID-19 patients

Can SARS-CoV-2 hitchhike on the olfactory projection and take a direct and short route from the nose into the brain? We reasoned that the neurotropic or neuroinvasive capacity of the virus, if it exists, should be most easily detectable in individuals who died in an acute phase of the infection. Here, we applied a postmortem bedside surgical procedure for the rapid procurement of tissue, blood, and cerebrospinal fluid samples from deceased COVID-19 patients infected with the Delta, Omicron BA.1, or Omicron BA.2 variants. Confocal imaging of sections stained with fluorescence RNAscope and immunohistochemistry afforded the light-microscopic visualization of extracellular SARS-CoV-2 virions in tissues. We failed to find evidence for viral invasion of the parenchyma of the olfactory bulb and the frontal lobe of the brain. Instead, we identified anatomical barriers at vulnerable interfaces, exemplified by perineurial olfactory nerve fibroblasts enwrapping olfactory axon fascicles in the lamina propria of the olfactory mucosa.

Epithelial and sensory mechanisms of nasal hyperreactivity

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

Visualizing in deceased COVID-19 patients how SARS-CoV-2 attacks the respiratory and olfactory mucosae but spares the olfactory bulb

Anosmia, the loss of smell, is a common and often the sole symptom of COVID-19. The onset of the sequence of pathobiological events leading to olfactory dysfunction remains obscure. Here, we have developed a postmortem bedside surgical procedure to harvest endoscopically samples of respiratory and olfactory mucosae and whole olfactory bulbs. Our cohort of 85 cases included COVID-19 patients who died a few days after infection with SARS-CoV-2, enabling us to catch the virus while it was still replicating. We found that sustentacular cells are the major target cell type in the olfactory mucosa. We failed to find evidence for infection of olfactory sensory neurons, and the parenchyma of the olfactory bulb is spared as well. Thus, SARS-CoV-2 does not appear to be a neurotropic virus. We postulate that transient insufficient support from sustentacular cells triggers transient olfactory dysfunction in COVID-19. Olfactory sensory neurons would become affected without getting infected.

Bacteriophage Therapy for Difficult-to-Treat Infections: The Implementation of a Multidisciplinary Phage Task Force (The PHAGEFORCE Study Protocol)

In times where only a few novel antibiotics are to be expected, antimicrobial resistance remains an expanding global health threat. In case of chronic infections caused by therapy-resistant pathogens, physicians have limited therapeutic options, which are often associated with detrimental consequences for the patient. This has resulted in a renewed interest in alternative strategies, such as bacteriophage (phage) therapy. However, there are still important hurdles that currently impede the more widespread implementation of phage therapy in clinical practice. First, the limited number of good-quality case series and clinical trials have failed to show the optimal application protocol in terms of route of administration, frequency of administration, treatment duration and phage titer. Second, there is limited information on the systemic effects of phage therapy. Finally, in the past, phage therapy has been applied intuitively in terms of the selection of phages and their combination as parts of phage cocktails. This has led to an enormous heterogeneity in previously published studies, resulting in a lack of reliable safety and efficacy data for phage therapy. We hereby present a study protocol that addresses these scientific hurdles using a multidisciplinary approach, bringing together the experience of clinical, pharmaceutical and molecular microbiology experts.

The Potential Role of Bacteriophages in the Treatment of Recalcitrant Chronic Rhinosinusitis

Chronic rhinosinusitis is a common condition affecting 5-12% of the general population worldwide. In a limited number of cases, the disease is recalcitrant to medical and surgical interventions, causing a major impact on physical, social and emotional well-being and increasing pressure on healthcare systems. Biofilm formation and dysbiosis caused by Staphylococcus aureus and Pseudomonas aeruginosa play a role in the pathogenesis of recalcitrant chronic rhinosinusitis. In these cases, a promising treatment alternative is the application of bacteriophages, which are viruses that infect and lyse bacteria. In this review, we appraise the evidence for the use of bacteriophages in the treatment of recalcitrant chronic rhinosinusitis. Additionally, (dis)advantages of bacteriophages and considerations for implementation of phage therapy in otorhinolaryngology practice will be discussed.

Endoscopic, Endonasal Transsphenoidal Surgery for Tumors of the Sellar and Suprasellar Region: A Monocentric Historical Cohort Study of 369 Patients

BACKGROUND

The endoscopic endonasal transsphenoidal approach (EETA) is an established technique for the resection of a large variety of benign sellar and suprasellar lesions, mostly pituitary adenomas. It has clear advantages over the microscopic approach, like a superior close-up view of the relevant anatomy and the tumor-gland interface, an enlarged working angle, as well as an increased panoramic vision inside the surgical area. We have been performing the EETA for over a decade, and this study will focus on perioperative and postoperative outcomes and complications and their association with the learning curve.

MATERIAL AND METHODS

All patients in our tertiary referral center (n = 369) undergoing an EETA for a lesion of the sellar and suprasellar region between January 1st 2008 and December 31st 2018 were included, and data were retrospectively retrieved from the electronic patient records.

RESULTS

Median follow-up after surgery was 55 months. Pituitary adenomas (n = 322) were the most frequent pathology. Headache (43.4%) and loss of vision (29.3%) were the most common presenting symptoms. Median procedure duration was significantly longer during the initial 5 years (106 versus 79 minutes; p <0.0001), but incidence of peri- and postoperative CSF leaks in the early years was not significantly higher. Knosp grade >2 was associated with perioperative CSF leak (p =0.002), and perioperative CSF leak was associated with postoperative CSF leak (p <0.001). Almost all cases of meningitis were preceded by a postoperative CSF leak. In 22.4% of patients, tumor recurrence required additional therapy. Perioperative (iatrogenic) mortality was 0.8%. The overall hospital stay decreased over time from an average of 7 to 5 days, and the case load increased yearly (p =0.015).

CONCLUSION

The EETA is an excellent technique with complication rates comparable to or even lower than those in large microsurgical series in the literature. EETA has a significant learning curve affecting the procedure duration. Throughout the first 10 years following the transition from the microscopic approach to the EETA in our cohort, the caseload increased and hospital stay was reduced, while no increase in peri- and postoperative complications was observed.

A TRiP Through the Roles of Transient Receptor Potential Cation Channels in Type 2 Upper Airway Inflammation

PURPOSE OF REVIEW

Despite their high prevalence, the pathophysiology of allergic rhinitis (AR) and chronic rhinosinusitis (CRS) remains unclear. Recently, transient receptor potential (TRP) cation channels emerged as important players in type 2 upper airway inflammatory disorders. In this review, we aim to discuss known and yet to be explored roles of TRP channels in the pathophysiology of AR and CRS with nasal polyps.

RECENT FINDINGS

TRP channels participate in a plethora of cellular functions and are expressed on T cells, mast cells, respiratory epithelial cells, and sensory neurons of the upper airways. In chronic upper airway inflammation, TRP vanilloid 1 is mostly studied in relation to nasal hyperreactivity. Several other TRP channels such as TRP vanilloid 4, TRP ankyrin 1, TRP melastatin channels, and TRP canonical channels also have important functions, rendering them potential targets for therapy. The role of TRP channels in type 2 inflammatory upper airway diseases is steadily being uncovered and increasingly recognized. Modulation of TRP channels may offer therapeutic perspectives.

A Method Based on 3D Shape Analysis Towards the Design of Flexible Instruments for Endoscopic Maxillary Sinus Surgery

The emergence of steerable flexible instruments has widened the uptake of minimally invasive surgical techniques. In sinus surgery, such flexible instruments could enable the access to difficult-to-reach anatomical areas. However, design-oriented metrics, essential for the development of steerable flexible instruments for maxillary sinus surgery, are still lacking. This paper proposes a method to process measurements and provides the instrument designer with essential information to develop adapted flexible instruments for limited access surgery. This method was applied to maxillary sinus surgery and showed that an instrument with a diameter smaller than 2.4 mm can be used on more than 72.5% of the subjects' set. Based on the statistical analysis and provided that this flexible instrument can bend up to [Formula: see text] it is estimated that all areas within the maxillary sinus could be reached through a regular antrostomy without resorting to extra incision or tissue removal in 94.9% of the population set. The presented method was partially validated by conducting cadaver experiments.

Real-life assessment of chronic rhinosinusitis patients using mobile technology: The mySinusitisCoach project by EUFOREA

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease associated with a substantial personal and socioeconomic burden. Monitoring of patient-reported outcomes by mobile technology offers the possibility to better understand real-life burden of CRS.

METHODS

This study reports on the cross-sectional evaluation of data of 626 users of mySinusitisCoach (mSC), a mobile application for CRS patients. Patient characteristics of mSC users were analysed as well as the level of disease control based on VAS global rhinosinusitis symptom score and adapted EPOS criteria.

RESULTS

The mSC cohort represents a heterogeneous group of CRS patients with a diverse pattern of major symptoms. Approximately half of patients reported nasal polyps. 47.3% of all CRS patients were uncontrolled based on evaluation of VAS global rhinosinusitis symptom score compared to 40.9% based on adapted EPOS criteria. The impact of CRS on sleep quality and daily life activities was significantly higher in uncontrolled versus well-controlled patients. Half of patients had a history of FESS (functional endoscopic sinus surgery) and reported lower symptom severity compared to patients without a history of FESS, except for patients with a history of more than 3 procedures. Patients with a history of FESS reported higher VAS levels for impaired smell.

CONCLUSION

Real-life data confirm the high disease burden in uncontrolled CRS patients, clearly impacting quality of life. Sinus surgery improves patient-reported outcomes, but not in patients with a history of more than 3 procedures. Mobile technology opens a new era of real-life monitoring, supporting the evolution of care towards precision medicine.

How to approach complications of acute rhinosinusitis in children?

Intraorbital and intracranial complications of acute rhinosinusitis (ARS) are uncommon, but potentially life threatening. Signs of progression of ARS should be recognized early to allow timely surgical treatment in order to avoid irreversible lesions such as vision loss and neurological deficits. In this case series, we provide an overview of 6 representative cases who presented at our tertiary center (2017-2018). The aim of this case series is (1) to draw new attention to the clinical manifestations and management of these complications, since even in highly-developed medical settings we still observe permanent sequellae due to delayed or inadequate treatment, (2) to give an updated analysis of the guidelines, stressing the low threshold for endoscopic sinus surgery, even in children, (3) to underline the benefits of a multidisciplinary approach in these young patients.

COVID-19 and gastrointestinal endoscopy: What should be taken into account?

On March 11, 2020 the World Health Organization declared COVID-19 pandemic, leading to a subsequent impact on the entire world and health care system. Since the causing Severe Acute Respiratory Syndrome Coronavirus 2 houses in the aerodigestive tract, activities in the gastrointestinal outpatient clinic and endoscopy unit should be limited to emergencies only. Health care professionals are faced with the need to perform endoscopic or endoluminal emergency procedures in patients with a confirmed positive or unknown COVID-19 status. With this report, we aim to provide recommendations and practical relevant information for gastroenterologists based on the limited amount of available data and local experience, to guarantee a high-quality patient care and adequate infection prevention in the gastroenterology clinic.

Prevalence and triggers of self-reported nasal hyperreactivity in adults with asthma

BACKGROUND

Nasal hyperreactivity (NHR) is a common feature of various rhinitis subtypes and represents a novel phenotype of rhinitis. It is being reported in two-thirds of adult rhinitis patients irrespective of the atopic status. Data on the prevalence of NHR in patients with asthma are lacking, as well as the nature of evoking triggers.

METHODS

Postal questionnaires were distributed to an unselected group of asthmatic patients in Leuven (Belgium, n = 190) and completed by 114 patients. In Mexico City (Mexico) and Brasov (Romania), respectively, 97 out of 110 and 80 out of 100 asthmatic patients attending the outpatient clinic completed the questionnaire. Non-asthmatic volunteers were recruited amongst university and hospital co-workers in Leuven (n = 53). The presence of self-reported NHR, the type of triggers evoking nasal and bronchial symptoms, medication use, self-reported allergy, and environmental factors were evaluated.

RESULTS

Overall, 69% of asthma patients reported NHR, with 32% having more than 4 triggers evoking NHR. These triggers included mainly exposure to temperature and humidity changes, cigarette smoke, and strong odours. A higher prevalence of NHR was detected in allergic compared to non-allergic asthma patients (73% vs. 53% p < 0.01). The prevalence of NHR correlated with asthma severity, ranging from 63% (VAS ≤3) to 81% (VAS ≥7). BHR was found more frequently in patients with NHR compared to without NHR (89% vs. 53%, p < 0.0001).

CONCLUSION

NHR represents a clinical phenotype of upper airway disease affecting over two-thirds of asthma patients and correlates with asthma severity. Targeting NHR in patients with asthma is often overlooked and should be reinforced in the future to achieve better symptom control.

Immunoactive preparations and regulatory responses in the respiratory tract: potential for clinical application in chronic inflammatory airway diseases

Introduction: The prevalence of chronic inflammatory airway diseases is rising. Their treatment with corticosteroids increases infection risk, while overuse of antimicrobial agents may increase morbidity and antimicrobial resistance. Nonspecific immunomodulatory compounds alter immune responses to both infectious and atopic challenges. These compounds may offer an alternative approach for symptom reduction and prophylaxis against both infections and exacerbations in chronic inflammatory airway disease.Areas covered: We assessed the available data on the efficacy of nonspecific immunomodulators including bacterial lysates, synthetic compounds, and vaccines in chronic rhinosinusitis (CRS); allergic and non-allergic rhinitis; chronic obstructive pulmonary disease (COPD), and asthma. A search of PubMed was carried out using the 'Clinical Trials' filter for each condition and immunomodulatory product detailed below, where available, data from meta-analyses were reported.Expert opinion: Pre-clinical data has revealed a coherent mechanistic path of action for oral immunomodulators on the respiratory immune system, principally via the gut-lung immune axis. In patients with asthma, allergic rhinitis, CRS, and COPD immunomodulatory therapy reduces symptoms, exacerbations, hospitalizations, and drug consumption. However, data are heterogeneous, and study quality remains limited. A lack of high-quality recent trials remains the major unmet research need in the field.

Expert curation of the human and mouse olfactory receptor gene repertoires identifies conserved coding regions split across two exons

BACKGROUND

Olfactory receptor (OR) genes are the largest multi-gene family in the mammalian genome, with 874 in human and 1483 loci in mouse (including pseudogenes). The expansion of the OR gene repertoire has occurred through numerous duplication events followed by diversification, resulting in a large number of highly similar paralogous genes. These characteristics have made the annotation of the complete OR gene repertoire a complex task. Most OR genes have been predicted in silico and are typically annotated as intronless coding sequences.

RESULTS

Here we have developed an expert curation pipeline to analyse and annotate every OR gene in the human and mouse reference genomes. By combining evidence from structural features, evolutionary conservation and experimental data, we have unified the annotation of these gene families, and have systematically determined the protein-coding potential of each locus. We have defined the non-coding regions of many OR genes, enabling us to generate full-length transcript models. We found that 13 human and 41 mouse OR loci have coding sequences that are split across two exons. These split OR genes are conserved across mammals, and are expressed at the same level as protein-coding OR genes with an intronless coding region. Our findings challenge the long-standing and widespread notion that the coding region of a vertebrate OR gene is contained within a single exon.

CONCLUSIONS

This work provides the most comprehensive curation effort of the human and mouse OR gene repertoires to date. The complete annotation has been integrated into the GENCODE reference gene set, for immediate availability to the research community.

A transcriptomic atlas of mammalian olfactory mucosae reveals an evolutionary influence on food odor detection in humans

The mammalian olfactory system displays species-specific adaptations to different ecological niches. To investigate the evolutionary dynamics of olfactory sensory neuron (OSN) subtypes across mammalian evolution, we applied RNA sequencing of whole olfactory mucosa samples from mouse, rat, dog, marmoset, macaque, and human. We find that OSN subtypes, representative of all known mouse chemosensory receptor gene families, are present in all analyzed species. Further, we show that OSN subtypes expressing canonical olfactory receptors are distributed across a large dynamic range and that homologous subtypes can be either highly abundant across all species or species/order specific. Highly abundant mouse and human OSN subtypes detect odorants with similar sensory profiles and sense ecologically relevant odorants, such as mouse semiochemicals or human key food odorants. Together, our results allow for a better understanding of the evolution of mammalian olfaction in mammals and provide insights into the possible functions of highly abundant OSN subtypes.

Plasma-rich fibrin in neurosurgery: a feasibility study

BACKGROUND

Cerebrospinal fluid (CSF) leakage represents an important and sometimes challenging complication in both cranial and spinal surgery. Current available options for dural closure pose inherent problems regarding safety, efficacy, immunogenicity, cost, and invasiveness. In this article, the use of leukocyte- and platelet-rich fibrin (L-PRF) derived from the patient's own blood is proposed to facilitate dural closure. We aim to describe the safety, feasibility, and applicability of L-PRF membranes and plugs in cranial and spinal neurosurgery.

METHODS

A retrospective study reviewing clinical and surgical characteristics was conducted in 47 patients in whom the use of L-PRF was attempted to reinforce dural closure at a single institution during 1 year. Procedures included skull base, posterior fossa, and spinal revision surgeries.

RESULTS

L-PRF membranes and/or plugs were used in 44 surgeries. The preparation of L-PRF failed in three cases. L-PRF membranes were used as onlay grafts to augment sealing or sutured into a defect. No short-term complications related to the use of L-PRF were recorded. Postoperative CSF leakage was present in two endoscopic transsphenoidal pituitary surgeries and in one spinal CSF leak repair.

CONCLUSION

L-PRF is safe, inexpensive, and completely autologous and can be rapidly and non-invasively harvested to aid in dural closure. Theoretical advantages include a regenerative bioactive potential, which could lead to improved wound healing and reduced infection rates. These findings warrant larger prospective studies to determine the potential role of L-PRF in neurosurgery.

Lack of long-term add-on effect by montelukast in postoperative chronic rhinosinusitis patients with nasal polyps

OBJECTIVES/HYPOTHESIS

Eosinophils and mast cells are among the key cells in inflammatory diseases like chronic rhinosinusitis (CRS) and asthma. Leukotriene antagonists have proven to be effective in the treatment of asthma, but data about their efficacy in CRS are scarce, whereas data on montelukast as an add-on treatment to intranasal corticosteroids (INCS) in a postoperative setting are completely lacking.

STUDY DESIGN

Prospective, randomized, open-label trial.

METHODS

In this trial with long-term follow-up, we evaluated the efficacy of montelukast as an add-on treatment to INCS in postoperative CRS with nasal polyp (CRSwNP) patients. CRSwNP patients (N = 72) undergoing endoscopic sinus surgery were randomized in two arms for the postoperative treatment. One group (N = 36) received INCS in monotherapy, whereas the other group (N = 36) received INCS in association with montelukast for 1 year. The efficacy of montelukast with INCS was evaluated by assessing both subjective (total five-symptom score [T5SS]) and objective (nasal polyp score [NPS], Lund-Mackay [LMK] score, and subjective olfactometry [Barcelona Smell Test 24]) outcome parameters and compared with the gold standard of INCS in monotherapy.

RESULTS

After 1 year of surgery, T5SS, NPS, and LMK score were significantly reduced in patients treated with either INCS or INCS plus montelukast, without significant differences between the two treatment arms. Improvement of smell loss by olfactometry was also observed with no differences between arms. Similar findings were observed at 3 and 6 months.

CONCLUSIONS

These results suggest that the addition of montelukast to INCS should not be recommended in the treatment of postoperative CRSwNP patients.

LEVEL OF EVIDENCE

1b Laryngoscope, 1743-1751, 2018.

Enhanced chemosensory sensitivity in patients with idiopathic rhinitis and its reversal by nasal capsaicin treatment

BACKGROUND

The therapeutic action of capsaicin treatment in patients with idiopathic rhinitis (IR) is based on ablation of the transient receptor potential cation channel subfamily V, receptor 1 (TRPV1)-substance P nociceptive signaling pathway. However, the functional consequences of capsaicin treatment on nasal nerve activation and the association between the reduction in nasal hyperreactivity (NHR) and response to capsaicin treatment remain unknown.

OBJECTIVE

We sought to study the effects of capsaicin nasal spray on the afferent innervation of the nasal mucosa by monitoring trigeminal nerve activity in patients with IR and healthy control (HC) subjects.

METHODS

A double-blind, placebo-controlled randomized trial with capsaicin nasal spray was performed involving 33 patients with IR and 12 HC subjects. Before and at 4, 12, and 26 weeks after treatment, nasal mucosal potentials (NMPs) were measured while exposing the nasal mucosa of patients with IR and HC subjects to aerosols with increasing doses of the chemical irritants allyl isothiocyanate (AITC; also known as mustard oil) or capsaicin. The threshold for each compound was determined for each subject. The results of the NMP measurements were evaluated in parallel with the therapeutic response, visual analog scale scores for nasal symptoms, self-reported NHR, and mRNA expression of PGP9.5; TRPV1; transient receptor potential cation channel subfamily A, receptor 1 (TRPA1); TRPV4; transient receptor potential cation channel subfamily M, member 8 (TRPM8); and nerve growth factor (NGF) in nasal biopsy specimens.

RESULTS

AITC turned out to be the best stimulus because the coughing induced by capsaicin interfered with measurements. At baseline, the threshold for evoking changes in NMPs based on AITC was significantly lower for patients with IR compared with HC subjects (P = .0423). Capsaicin treatment of IR patients increased the threshold for the response to AITC at 4 and 12 weeks compared with placebo (P = .0406 and P = .0325, respectively), which returned to baseline by week 26 (P = .0611). This increase correlated with changes in visual analog scale major symptom (P = .0004) and total symptom (P = .0018) scores. IR patients with self-reported NHR at baseline showed a trend to being better responders to capsaicin treatment compared with patients with IR but without NHR (P = .10).

CONCLUSION

The lower threshold for AITC based on NMPs in patients with IR compared with HC subjects and the increased threshold for AITC after capsaicin treatment in patients with IR demonstrate the crucial role of TRPA1 and TRPV1 in IR pathophysiology. The strong correlation between the increase in AITC threshold in patients with IR and symptom reduction after capsaicin treatment demonstrates the clinical relevance of these findings.

Impaired barrier function in patients with house dust mite-induced allergic rhinitis is accompanied by decreased occludin and zonula occludens-1 expression

BACKGROUND

Tight junction (TJ) defects have recently been associated with asthma and chronic rhinosinusitis. The expression, function, and regulation of nasal epithelial TJs remain unknown in patients with allergic rhinitis (AR).

OBJECTIVE

We investigated the expression, function, and regulation of TJs in the nasal epithelium of patients with house dust mite (HDM)-induced AR and in an HDM-induced murine model of allergic airway disease.

METHODS

Air-liquid interface cultures of primary nasal epithelial cells of control subjects and patients with HDM-induced AR were used for measuring transepithelial resistance and passage to fluorescein isothiocyanate-dextran 4 kDa (FD4). Ex vivo transtissue resistance and FD4 permeability of nasal mucosal explants were measured. TJ expression was evaluated by using real-time quantitative PCR and immunofluorescence. In addition, the effects of IL-4, IFN-γ, and fluticasone propionate (FP) on nasal epithelial cells were investigated in vitro. An HDM murine model was used to study the effects of allergic inflammation and FP treatment on transmucosal passage of FD4 in vivo.

RESULTS

A decreased resistance in vitro and ex vivo was found in patients with HDM-induced AR, with increased FD4 permeability and reduced occludin and zonula occludens-1 expression. AR symptoms correlated inversely with resistance in patients with HDM-induced AR. In vitro IL-4 decreased transepithelial resistance and increased FD4 permeability, whereas IFN-γ had no effect. FP prevented IL-4-induced barrier dysfunction in vitro. In an HDM murine model FP prevented the allergen-induced increased mucosal permeability.

CONCLUSION

We found impaired nasal epithelial barrier function in patients with HDM-induced AR, with lower occludin and zonula occludens-1 expression. IL-4 disrupted epithelial integrity in vitro, and FP restored barrier function. Better understanding of nasal barrier regulation might lead to a better understanding and treatment of AR.

Nasal allergen deposition leads to conjunctival mast cell degranulation in allergic rhinoconjunctivitis

BACKGROUND

The naso-ocular interaction in allergic rhinoconjunctivitis is well recognized from epidemiological, clinical, and experimental observations. The precise mechanisms remain incompletely understood. A new mouse model of allergic rhinoconjunctivitis was used to investigate the contribution of mast cells and trigeminal ganglia activation to conjunctival (conj.) inflammation after nasal allergen provocation.

METHODS

Sensitized mice were exposed to ovalbumin (OVA) via the nose and/or conjunctiva, and conj. homogenates were analyzed for histamine and substance P (using ELISA) and by eosinophil peroxidase (EPO) and beta-hexosaminidase assays. The conj. effects of nasal allergen deposition were compared with those induced by the mast cell activator C48/80 and with pretreatment of the mast cell stabilizer ketotifen or the transient receptor potential channel receptor (TRP) agonist capsaicin. Protachykinin 1 (TAC1) expression was quantified in the trigeminal ganglia using real time polymerase chain reaction.

RESULTS

At 1 hour after nasal application of OVA, increased conj. levels of beta-hexosaminidase (0.68 ± 0.03 nm versus 0.56 ± 0.02 nm; p = 0.02), histamine (751.1 ± 52.17 ng/mL versus 546.3 ± 76.91 ng/mL; p = 0.05), and EPO (0.66 ± 0.09 nm versus 0.37 ± 0.03 nm; p = 0.02) were detected compared with saline. Higher levels of TAC1 expression were found in the trigeminal ganglia at 24 hours after OVA application (1326 ± 255 versus 687.5 ± 90.77 TAC1/beta-actin; p = 0.04). Nasal challenge with C48/80 increased substance P and beta-hexosaminidase levels in the conjunctiva, as well as TAC1 expression. Pretreatment with ketotifen resulted in lower levels of substance P as well as TAC1 expression. Destruction of sensory nerves in the nose by capsaicin reduced the OVA-induced conj. levels of substance P, histamine, and beta-hexosaminidase.

CONCLUSION

Nasal allergen deposition in sensitized mice induced trigeminal TAC1 expression and conj. mast cell degranulation. These data represent a significant step forward in understanding the close interaction between nasal and conj. inflammation in allergy.

Long-term follow-up of 123 patients with adenocarcinoma of the sinonasal tract treated with endoscopic resection and postoperative radiation therapy

BACKGROUND

Most series about endoscopic resection of adenocarcinomas of the sinonasal tract present outcome data from a small heterogeneous group of patients with a relatively short follow-up period and a wide variety of histological subtypes and treatment protocols. This relatively large study with a very homogeneous study population updates our experience with a stable treatment protocol looking at survival rates, surgical technique, and prognostic factors.

METHODS

We conducted a retrospective analysis of the medical records of 123 patients with adenocarcinoma of the intestinal type primarily treated with endoscopic resection and postoperative radiotherapy (RT) in a single tertiary referral center during the period 1992 to 2010.

RESULTS

Mean follow-up was 66 months and median follow-up was 54 months. Mean and median follow-up of the subgroup of patients alive at the end of follow-up was 74 months and 61 months, respectively. At 5-years of follow-up, overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were 68%, 82%, and 62% respectively. At 10-year follow-up, these numbers were 51%, 74%, and 45%, respectively. Prognostic factors for treatment outcome are predominantly local recurrence, development of distant metastasis, T classification, histopathological classification, and the center where the first surgery was performed.

CONCLUSION

This large study of sinonasal adenocarcinoma primarily treated with endoscopic resection and RT confirms that this approach results in good oncologic and functional outcome.

Short-time cold dry air exposure: a useful diagnostic tool for nasal hyperresponsiveness

OBJECTIVES/HYPOTHESIS

Demonstration of nasal hyperreactivity (NHR) in allergic and nonallergic rhinitis remains a diagnostic challenge because of the lack of a clinically attractive protocol with high sensitivity and specificity. Our aim was to evaluate the feasibility of a shortened cold dry air (CDA) provocation protocol for the diagnosis of NHR in patients with allergic rhinitis (AR) and idiopathic rhinitis (IR).

STUDY DESIGN

Twelve AR patients, 12 IR patients, and 12 controls were exposed to air at -10°C and <10% humidity for 15 minutes.

METHODS

Nasal symptoms were subjectively evaluated by visual analogue scale (VAS), and nasal obstruction was objectively measured by peak nasal inspiratory flow (PNIF) before and after CDA exposure. NHR was defined as a drop in PNIF larger than 20% from baseline upon CDA challenge.

RESULTS

Nasal CDA exposure induced nasal obstruction in AR and IR patients but not in controls. The VAS for nasal obstruction increased significantly in IR patients (post-CDA: 9.1 cm [6.9, 9.7] vs. pre-CDA: 5.5 cm [5.0, 8.9], P = .004) as well as in AR patients (post-CDA: 5.0 cm [1.3, 6.6] vs. pre-CDA: 0.8 cm [0.0, 1.7], P = .001). PNIF values showed a significant decrease in the AR (post-CDA: 50.0 L/min [37.5, 97.5] vs. pre-CDA: 95.0 L/min [52.5, 127.5], P = .002) and IR (post-CDA: 75.0 L/min [47.5, 102.5] vs. pre-CDA: 100.0 L/min [67.5, 130.0], P = .002) group after CDA provocation, which was not observed in the controls (P = 1.000). The sensitivity and specificity of CDA provocation for diagnosis of NHR were 66.7% and 100%, respectively, for both IR and AR. In contrast to nasal obstruction, rhinorrhea and sneezing were not induced by CDA exposure.

CONCLUSIONS

This study demonstrates that a short nasal CDA exposure is a reliable method for the diagnosis of NHR in rhinitis patients, with a high sensitivity and specificity.