Reversal of Chronic Rhinosinusitis-Associated Sinonasal Ciliary Dysfunction

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.

S-Nitrosoglutathione Reduces the Density of Staphylococcus aureus Biofilms Established on Human Airway Epithelial Cells

Patients with chronic rhinosinusitis (CRS) often show persistent colonization by bacteria in the form of biofilms which are resistant to antibiotic treatment. One of the most commonly isolated bacteria in CRS is Staphylococcus aureus (S. aureus). Nitric oxide (NO) is a potent antimicrobial agent and disperses biofilms efficiently. We hypothesized that S-nitrosoglutathione (GSNO), an endogenous NO carrier/donor, synergizes with gentamicin to disperse and reduce the bacterial biofilm density. We prepared GSNO formulations which are stable up to 12 months at room temperature and show the maximum amount of NO release within 1 h. We examined the effects of this GSNO formulation on the S. aureus biofilm established on the apical surface of the mucociliary-differentiated airway epithelial cell cultures regenerated from airway basal (stem) cells from cystic fibrosis (CF) and CRS patients. We demonstrate that for CF cells, which are defective in producing NO, treatment with GSNO at 100 μM increased the NO levels on the apical surface and reduced the biofilm bacterial density by 2 log units without stimulating pro-inflammatory effects or inducing epithelial cell death. In combination with gentamicin, GSNO further enhanced the killing of biofilm bacteria. Compared to placebo, GSNO significantly increased the ciliary beat frequency (CBF) in both infected and uninfected CF cell cultures. The combination of GSNO and gentamicin also reduced the bacterial density of biofilms grown on sinonasal epithelial cells from CRS patients and improved the CBF. These findings demonstrate that GSNO in combination with gentamicin may effectively reduce the density of biofilm bacteria in CRS patients. GSNO treatment may also enhance the mucociliary clearance by improving the CBF.

Septum submucosal glands exhibit aberrant morphology and reduced mucin production in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) is characterized by significant accumulation and thickening of mucus in the sinonasal cavities. One contributor of aberrant mucus production and impaired mucociliary clearance (MCC) is altered function of the sinonasal submucosal glands (SMGs), yet contributions of SMGs to upper airway disease initiation and progression remain unknown. The objective of this study was to characterize the morphology and secretory cell identities of the nasal septum SMGs in both healthy and CRS adults.

METHODS

Biopsies from adult participants with CRS without nasal polyps (CRSsNP, n = 4), CRS with nasal polyps (CRSwNP, n = 8), and non-CRS controls (n = 14) were collected from the posterior septum. Glandular morphology and mucus markers were investigated using histological techniques and high-resolution confocal microscopy.

RESULTS

Analysis revealed a significant decrease in gland density in the posterior septum of CRSsNP (28% ± 6.15%) and CRSwNP (23% ± 3.09%) compared to control participants (53% ± 1.59%, p < 0.0001). Further analysis of the CRS SMG secretory function revealed an overall decrease in Mucin 5B+ gland mucus being produced. Dilated and cystic ductal structures filled with inspissated mucus were also common to CRS glands.

CONCLUSION

Here, we describe a significant alteration in SMG structure and function in the adult CRS posterior septum suggesting reduced gland contribution to MCC. The SMGs of both the nose and sinuses may represent targets for future therapeutic approaches.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

In vitro safety of ketotifen as a topical nasal rinse

BACKGROUND

Ketotifen is a second-generation noncompetitive H1-antihistamine and mast-cell stabilizer. It is commonly used to treat or prevent allergic conjunctivitis, asthma, chronic urticaria, anaphylaxis, mast-cell, and other allergic-type disorders. However, it has never been studied in aspirin-exacerbated respiratory disease (AERD), an aggressive phenotype of chronic rhinosinusitis with nasal polyps, where the mast cell plays a prominent role its pathogenesis.

METHODS

Human sinonasal epithelial cells were grown at an air-liquid interface (ALI). Ketotifen powder was dissolved in saline to make 4 test solutions at 1.04, 2.08, 10.4, and 20.8 µg/mL. Control (saline) or ketotifen solution was added apically to ALI cultures from tissue of 5 unique patients, and ciliary beat frequency (CBF) changes were recorded. Lactate dehydrogenase was measured at 24 and 48 hours to estimate long-term cellular toxicity.

RESULTS

Apical application of ketotifen at all concentrations was neither ciliotoxic nor ciliostimulatory, with no change in CBF over a period of 15 minutes after application. Cellular toxicity for all concentrations at 24 and 48 hours after application was <3% and <7%, respectively, that of lysed cultures.

CONCLUSION

Topical application of ketotifen to an in vitro model of sinonasal epithelium is safe, as evaluated by CBF and lactate dehydrogenase. Ketotifen is neither ciliotoxic nor ciliostimulatory, and no long-term cellular toxicity was observed. Ketotifen may have promise as a topical nasal rinse in the treatment of AERD.

Nasal mucociliary clearance and hearing loss in pseudoexfoliation syndrome

PURPOSE

To evaluate nasal mucociliary clearance (NMC) and hearing loss in patients with pseudoexfoliation (PEX) syndrome.

METHODS

The study included 36 patients with PEX syndrome as the study group, and 39 healthy individuals as the control group. The duration of NMC was measured using the saccharine test. Audiometry was applied at 250, 500, 1000, 2000, 4000, 6000 and 8000 Hz frequencies to determine hearing thresholds and prevalence of hearing loss.

RESULTS

No statistically significant difference was determined between the groups in respect of age and gender (p = 0.23 and p = 0.36, respectively). In the saccharine test, the mean NMC time was 18.41 ± 8.53 min for the study group and 11.69 ± 4.96 min for the control group. The mean NMC time of study group was significantly longer than that of the controls (p < 0.001). In the comparisons of the two groups in terms of the prevalence of hearing loss, no statistically significant difference was found at any of the evaluated frequencies (p > 0.05, for all). There was also no statically significant difference between groups in relation to hearing thresholds at these frequencies (p > 0.05, for all).

CONCLUSION

The NMC time was significantly prolonged in patients with PEX syndrome. This result indicates that nasal mucosa cilia, which have similar elastic and mobile structures as the iris, are damaged in PEX syndrome, which is an infiltrative disease increasing the rigidity of affected tissues. In upper respiratory tract infections of unknown cause, PEX syndrome should be considered among the etiological factors. In this study, no significant relationship was detected between PEX and hearing loss.

Epithelial cell function and remodeling in nasal polyposis

OBJECTIVE

To review the latest discoveries on airway epithelial cell diversity and remodeling in type 2 inflammation, including nasal polyposis.

DATA SOURCES

Reviews and primary research manuscripts were identified from PubMed, Google, and Bioarchives, using the search words airway epithelium, nasal polyposis, or chronic rhinosinusitis with nasal polyposis AND basal cell, ciliated cell, secretory cell, goblet cell, neuroendocrine cell, pulmonary neuroendocrine cell, ionocyte, brush cell, solitary chemosensory cell, microvillus cell, or tuft cell.

STUDY SELECTIONS

Studies were selected based on novelty and likely relevance to airway epithelial innate immune functions or the pathobiology of type 2 inflammation.

RESULTS

Airway epithelial cells are more diverse than previously appreciated, with specialized subsets, including ionocytes, solitary chemosensory cells, and neuroendocrine cells that contribute to important innate immune functions. In chronic rhinosinusitis with nasal polyposis, the composition of the epithelium is significantly altered. Loss of ciliated cells and submucosal glands and an increase in basal airway epithelial progenitors leads to loss of innate immune functions and an expansion of proinflammatory potential. Type 2 cytokines play a major role in driving this process.

CONCLUSION

Airway epithelial remodeling in chronic rhinosinusitis is extensive, leading to loss of innate immune function and enhanced proinflammatory potential. The mechanisms driving airway remodeling and its sequelae deserve further attention before restitution of epithelial differentiation can be considered a reasonable therapeutic target.

Responses of Well-differentiated Human Sinonasal Epithelial Cells to Allergen Exposure and Environmental Pollution in Chronic Rhinosinusitis

Background

Evidence suggests that intrinsic cell dysfunction leads to dysregulated immune responses to environmental triggers in chronic rhinosinusitis (CRS). Although epidemiological and in vivo studies support this theory, in vitro studies are lacking.

Methods

Epithelial cells from human sinonasal mucosa were cultured using an air–liquid interface culture model producing a well-differentiated phenotype. Specimens were characterized as chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyps and healthy control mucosa. Culture wells were exposed to house dust mite (HDM), diesel exhaust particles (DPM), or a combination (HDM + DPM) over 24 hours and responses in the 3 groups compared. Ciliary beat frequency (CBF) and transepithelial electrical resistance (TEER) were measured to assess mucociliary and barrier function, respectively. Interleukin-6 (IL-6) and 33 (IL-33) were measured after 24 hours. Results following challenge testing are expressed as fold change from baseline.

Results

Baseline CBF was lower in CRSsNP compared with control (5.27 ± 0.51 Hz vs 5.88 ± 1.22 Hz, P = .003). HDM significantly reduced CBF and TEER in the CRSwNP group compared with its vehicle (CBF: 0.55 ± 0.25 vs 1.03 ± 0.22, P < .001; TEER: 0.54 [0.13] Ω cm2 vs 0.93 [0.5] Ω cm2, P = .001). In CRSwNP and CRSsNP, HDM induced an increase in IL-6 compared with its vehicle (CRSwNP: 81.11 [67.19] pg/mL vs 3.15 [44.64] pg/mL, P = .016; CRSsNP: 321.46 [182.04] pg/mL vs 21.54 [53.93] pg/mL, P = .004). Results are expressed as median (interquartile range) and in IL-33 in CRswNP (84.04 [69.96] pg/mL vs 16.62 [20.19] pg/mL, P = .025). Exposure to DPM did not affect CBF, TEER, and cytokine release in all groups.

Conclusion

CRSwNP and CRSsNP cells exhibit altered responses particularly to HDM even after they have been removed from their host and cultured in vitro, suggesting an intrinsic cell dysfunction of the upper airway epithelium.

Broncho-Vaxom® (OM-85 BV) soluble components stimulate sinonasal innate immunity

BACKGROUND

Broncho-Vaxom® (OM-85 BV) is an extract of infectious respiratory bacteria that is used as an immunostimulant outside of the United States for the prevention and treatment of bronchitis and rhinosinusitis. Prior studies have shown that use of OM-85 BV is associated with reduction in frequency of respiratory infection and decreased duration of antibiotic usage. However, the effects of OM-85 BV on respiratory mucosal innate immunity are unknown.

METHODS

Human sinonasal epithelial cells were grown at an air-liquid interface (ALI). Ciliary beat frequency (CBF) and nitric oxide (NO) production in response to stimulation with OM-85 BV was measured in vitro. Pharmacologic inhibitors of bitter taste receptor (T2R) signaling were used to determine if this pathway was taste-receptor-mediated.

RESULTS

Apical application of OM-85 BV resulted in an NO-mediated increase in CBF (p < 0.05) and increased NO production (p < 0.0001) when compared to saline-stimulated control cultures. ALI pretreatment with taste receptor pathway inhibitors blocked OM-85 BV-induced increases in NO.

CONCLUSION

OM-85 BV has ciliostimulatory and immunogenic properties that may be partially responsible for its observed efficacy as a respiratory therapeutic. These responses were NO-dependent and consistent with T2R activation. Further work is necessary to elucidate specific component-receptor signaling relationships.

Precision medicine in united airways disease: A "treatable traits" approach

United airways disease (UAD) is the concept that the upper and lower airways, which are anatomically and immunologically related, form a single organ. According to this concept, upper and lower airway diseases are frequently comorbid because they reflect manifestations of a single underlying disease at different sites of the respiratory tract. Allergic asthma-allergic rhinitis is the archetypal UAD, but emerging data indicate that UAD is a heterogeneous condition and consists of multiple phenotypes (observable clinical characteristics) and endotypes (pathobiologic mechanisms). The UAD paradigm also extends to myriad sinonasal diseases (eg, chronic rhinosinusitis with or without nasal polyps) and lower airway diseases (eg, bronchiectasis, chronic obstructive pulmonary disease). Here, we review currently known phenoendotypes of UAD and propose a "treatable traits" approach for the classification and management of UAD, wherein pathophysiological mechanisms and factors contributing to disease are identified and targeted for treatment. Treatable traits in UAD can be analyzed according to a framework comprising airway inflammation (eosinophilic, neutrophilic), impaired airway mucosal defense (impaired mucociliary clearance, antibody deficiency), and exogenous cofactors (allergic sensitizers, tobacco smoke, microbes). Appreciation of treatable traits is necessary in advancing the effort to deliver precise treatments and achieve better outcomes in patients with UAD.

Taste Receptor Polymorphisms and Immune Response: A Review of Receptor Genotypic-Phenotypic Variations and Their Relevance to Chronic Rhinosinusitis

Bitter (T2R) and sweet taste (T1R) receptors have emerged as regulators of upper airway immune responses. Genetic variation of these taste receptors additionally confers susceptibility to infection and has been implicated in severity of disease in chronic rhinosinusitis (CRS). Ongoing taste receptor research has identified a variety of biologically active compounds that activate T1R and T2R receptors, increasing our understanding of not only additional receptor isoforms and their function but also how receptor function may contribute to the pathophysiology of CRS. This review will discuss the function of taste receptors in mediating airway immunity with a focus on recently described modulators of receptor function and directions for future research into the potential role of genotypic and phenotypic receptor variation as a predictor of airway disease and response to therapy.

Chronic Rhinosinusitis without Nasal Polyps

Chronic rhinosinusitis without nasal polyps (CRSsNP) is more prevalent than chronic rhinosinusitis with nasal polyps (CRSwNP). Certain diseases predispose to whereas others are associated with CRSsNP. Predisposing diseases include allergic and nonallergic upper and lower airway diseases, epithelial cell disorders, immunodeficiencies, autoimmune diseases, and some infectious diseases. In addition, environmental and host factors, examples of which include smoking, a higher incidence of abnormal biofilms, and innate immune defects, play a role in the pathogenesis of this disease. CRSsNP is characterized by histologic abnormalities, including basement membrane thickening (fibrosis) and goblet cell hyperplasia. Neutrophils and several chemokines, TGF-β and C-X-C motif chemokine ligand (CXCL)-8, play a role in CRSsNP remodeling. However, there are conflicting data about CRSsNP endotypes, for example, whether it is characterized by neutrophilia or eosinophilia or both. In spite of advancements and the understanding of the pathogenesis of this disease, additional study is necessary to better comprehend its underlying mechanisms, endotypes, and evidence-based treatment strategies.

Genetic and Immune Dysregulation in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent condition that is heterogeneous in disease characteristics and multifactorial in cause. Although sinonasal mucosal inflammation in CRS is often either reversible or well-managed medically and surgically, a significant proportion of patients has a refractory form of CRS despite maximal therapy. Two of the several described factors thought to contribute to disease recalcitrance are genetic influences and dysfunction of the host immune system. Current evidence for a genetic basis of CRS is reviewed, as it pertains to putative abnormalities in innate and adaptive immune function. The role of systemic immunodeficiencies in refractory CRS is discussed.

Cytofunctional changes in nasal ciliated cells in patients treated with hyaluronate after nasal surgery

BACKGROUND

Hyaluronic acid (HA) plays a significant role in tissue repair of mucosal surfaces and, consequently, in surgical injury remodelling of nasal mucosa.

OBJECTIVE

To assess the effect of high-molecular-weight HA administered by aerosol on the morphofunctional recovery of ciliated cells damaged by surgical trauma.

METHODS

A single-blind, prospective, randomized trial was carried out with 94 patients who were randomly assigned, after endoscopic turbinoplasty, either to treatment with nasal saline solution irrigation (control group, n = 47) or to treatment with nasal douches based on high concentration (9 mg) and high-molecular-weight sodium hyaluronate (active treatment group, n = 47). All the patients were evaluated by using nasal fiberendoscopy, mucociliary transport time, nasal cytologic test, and a visual analog scale in terms of symptoms before and at 2 and 4 weeks after surgery.

RESULTS

Visual analog scale values were significantly lower in the active treatment (AT) group at week 2 regarding each individual symptom. Mucociliary transport time was significantly reduced in patients in the AT group but only 1 month after surgery. Both the percentage of cellular impairments and the number of cells with hyperchromatic supranuclear stria showed significant improvements in the AT group in all postsurgery evaluations (p < 0.05).

CONCLUSION

Intranasal use of sodium hyaluronate in patients who underwent functional nasal surgery improved both mucociliary clearance and nasal mucosa regeneration due to a faster recovery of the impaired ciliated cells.

Pediatric chronic rhinosinusitis

The goal of this review is to elucidate the pathogenic factors, histopathologic features, and special considerations that relate to pediatric versus adult chronic rhinosinusitis (CRS) and to emphasize differences and similarities between the adult and pediatric conditions. Emphasis is placed on understanding of the differences in pathogenic mechanisms, host-microbial interactions, potential defects in innate antimicrobial immunity, and the role of biofilm formation in pediatric versus adult CRS and how these translate to different approaches toward both medical and surgical management. Pediatric CRS can be viewed as evolving from acute bacterial rhinosinusitis into an uncomplicated "early" stage of CRS, later evolving into a persistent stage and, in some cases, evolving into a late "maladaptive-eosinophilic" stage disease. Given this potential evolution toward more irreversible disease, a plea can be made for improved recognition of and more aggressive early intervention for pediatric CRS, it is hoped, to prevent these long-term consequences. For the primary care physician, this may necessitate enlisting the support of a sinus specialist before the symptoms of CRS have persisted for months or years. It may also necessitate, in some cases, the use of sinus computed tomography imaging to demonstrate that sinus abnormalities have resolved. Other arguments can be made for prompt and comprehensive management of pediatric CRS, including the need to reduce the burden of illness, reduce health care costs, avoid unnecessary antibiotic use and its attendant effects toward promoting antibiotic resistant infections and, potentially, to reduce the development of important comorbidities, e.g., asthma.

Risk Factors and Comorbidities in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a heterogeneous disorder that creates a significant burden on the healthcare system. It is caused by a combination of inflammatory, environmental, and host factors; however, the precise mechanism of how each factor leads to CRS continues to be a source of debate. Previous data regarding this topic is often inconsistent or of lower quality. In this article, we review the recent literature on the risk factors and comorbidities in CRS. Large population-based studies have helped establish smoking as a significant risk factor for CRS. The focus has now shifted towards smoking and its effect on long-term outcomes after endoscopic sinus surgery (ESS). Ciliary dyskinesia, both primary and secondary, can affect both the sinonasal cavity and lower airways simultaneously by decreasing the beat frequency of cilia and inducing mucostasis. The effects of secondary dyskinesia may be reversible and there is some evidence to suggest the use of topical mucolytics in patients with CRS. Allergy and variants of sinonasal anatomy have been hypothesized to increase the risk of developing CRS by inducing chronic inflammation and obstructing the sinus ostia. Nevertheless, emerging data regarding these topics continue to produce inconclusive results. Inflammation of the upper and lower airways can occur simultaneously as seen in patients with asthma and aspirin sensitivity. The connection between these pro-inflammatory disease states has been known for many years. Newer evidence include large population-based studies and studies that correlate objective tests, such as computer tomography scans to pulmonary function tests. However, the treatment of CRS and its effects on obstructive airway disease continues to be a topic of debate. More large prospective studies are needed in order to continue refining our knowledge of the disease processes in CRS.

Nasal Mucociliary Clearance in Adenoid Hypertrophy and Otitis Media with Effusion

Mucociliary clearance (MCC), which exists in many systems, is the first defensive mechanism of the human body. Nasal MCC has an important role in transporting the secretions of the nasal cavity and paranasal sinuses along with the trapped inhaled pathogens to the nasopharynx. Physiologic or pathologic situations that effect nasal MCC, such as temperature, humidity, nasal obstruction, allergic rhinitis, chronic infections, etc., lead to impaired MCC and related local or circumjacent system disorders. With this perspective, when a unified airway with a multiple disease principle is considered, investigating the relationship between adenoid hypertrophy (AH), otitis media with effusion (OME) and nasal MCC is logical. In this review, histological and physiologic properties of nasal MCC and its possible role involving pathologic situations such as AH and OME is discussed together with recent literature findings.

The effect of drugs and other compounds on the ciliary beat frequency of human respiratory epithelium

BACKGROUND

Cilia in the human respiratory tract play a critical role in clearing mucus and debris from the airways. Their function can be affected by a number of drugs or other substances, many of which alter ciliary beat frequency (CBF). This has implications for diseases of the respiratory tract and nasal drug delivery. This article is a systematic review of the literature that examines 229 substances and their effect on CBF.

METHODS

MEDLINE was the primary database used for data collection. Eligibility criteria based on experimental design were established, and 152 studies were ultimately selected. Each individual trial for the substances tested was noted whenever possible, including concentration, time course, specific effect on CBF, and source of tissue.

RESULTS

There was a high degree of heterogeneity between the various experiments examined in this article. Substances and their general effects (increase, no effect, decrease) were grouped into six categories: antimicrobials and antivirals, pharmacologics, human biological products, organisms and toxins, drug excipients, and natural compounds/other manipulations.

CONCLUSION

Organisms, toxins, and drug excipients tend to show a cilioinhibitory effect, whereas substances in all other categories had mixed effects. All studies examined were in vitro experiments, and application of the results in vivo is confounded by several factors. The data presented in this article should be useful in future respiratory research and examination of compounds for therapeutic and drug delivery purposes.

The Etiology and Pathogenesis of Chronic Rhinosinusitis: a Review of Current Hypotheses

Chronic rhinosinusitis (CRS) is a broad clinical syndrome that is characterized by prolonged mucosal inflammation of the nose and paranasal sinuses, and is typically divided into two subtypes based on the presence or absence of nasal polyps. The etiology and pathogenesis of both forms remain areas of active research. Over the last 15 years, a number of hypotheses have been proposed to explain all or part of the clinical CRS spectrum. These hypotheses reflect the concept that CRS results from a dysfunctional interplay between individual host characteristics and factors exogenous to the host. Six broad theories on CRS etiology and pathogenesis are discussed as follows: (1) the "fungal hypothesis," (2) the "superantigen hypothesis," (3) the "biofilm hypothesis," and (4) the "microbiome hypothesis," all of which emphasize key environmental factors, and (5) the "eicosanoid hypothesis" and (6) the "immune barrier hypothesis," which describe specific host factors. These theories are reviewed, and the evidence supporting them is critically appraised.

In vitro studies of a distillate of rectified essential oils on sinonasal components of mucociliary clearance

BACKGROUND

Herbal remedies predate written history and continue to be used frequently for many common ailments. The essential oil mixture standardized is a phytopharmaceutical with a distillate of a mixture of rectified essential oils of eucalyptus, sweet orange, myrtle, and lemon as active ingredients used to treat respiratory diseases such as bronchitis and rhinosinusitis. We evaluated the pharmacologic effects of a distillate of rectified essential oils standardized on primary human upper respiratory epithelial cultures specifically addressing electrolyte transport, cilia beat frequency (CBF), airway surface liquid (ASL) hydration, and mucus transport velocity.

METHODS

Well-differentiated primary human sinonasal epithelial cultures grown at an air-liquid interface were treated on the apical or basolateral surface with varying concentrations of a distillate of rectified essential oils standardized. Changes in CBF were determined using the Sissons-Ammons Video Analysis system while changes in chloride flux were determined using the fluorescent dye 6-methoxy-N-(3-sulfopropyl)quinolinium. ASL hydration was quantified using Texas red dextran and mucociliary transport velocity was measured using fluorescent microspheres and time lapse photography.

RESULTS

When applied to the basolateral surface, a distillate of rectified essential oils standardized activated chloride efflux and ciliary beat in a dose-dependent fashion, increasing ASL height and accelerating mucociliary transport velocity. The ancillary apical application of a distillate of rectified essential oils standardized had minimal effects on the CBF.

CONCLUSION

Basolateral application of a distillate of rectified essential oils standardized stimulates both chloride efflux and cilia beat frequency resulting in a synergistic effect dramatically augmenting mucociliary transport velocity. These in vitro data support the clinical efficacy of this phytopharmaceutical in respiratory inflammatory disorders.

Effects of histamine on ciliary beat frequency of ciliated cells from guinea pigs nasal mucosa

We aimed to investigate the effect of histamine on ciliary beat frequency (CBF) through combining high-speed digital microscopy and patch-clamp technology. Ciliated cells were obtained from septum and turbinate of 90-120-day-old healthy male guinea pigs. Tight seal was formed by applying negative pressure on the glass electrode after the drawing and pushing progress. Then, we enrolled high-speed digital microscopy to measure CBF before and after treatment with histamine of different concentrations ranging from 10(-6) to 10(-1) mol/L in Hank's solution and D-Hank's solution as well as after administrating adenosine triphosphate. One-way ANOVA, Student's t test or Kruskal-Wallis test was used for statistical comparisons. Glass electrode fix up ciliated cell is available at tip diameter of 2-5 μm and negative pressure of 10-20 cmH2O column. The baseline CBF in Hank's solution was higher than in D-Hank's solution. Treatment with 10(-6)-l0(-3) mol/L histamine of concentrations can stimulate a rise of CBF. Nevertheless, CBF in all groups decreased to baseline CBF within 20 min. Generally, 10(-2) mol/L histamine can stimulate a rise of CBF; meanwhile, the high concentration of histamine killed 50% ciliated cell. Histamine at 10(-1) mol/L killed all ciliated cells. Ciliary beating activity decreased in Ca(2+)-free solution. Moreover, adenosine triphosphate could increase CBF effectively after the stimulation effect of histamine. We construct an effective technology integrating patch-clamp technique with CBF measurements on ciliated cells. Extracellular histamine stimulation could increase CBF effectively.

ICON: chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a public health problem that has a significant socio-economic impact. Moreover, the complexity of this disease due to its heterogeneous nature based on the underlying pathophysiology - leading to different disease variants - further complicates our understanding and directions for the most appropriate targeted treatment strategies. Several International/national guidelines/position papers and/or consensus documents are available that present the current knowledge and treatment strategies for CRS. Yet there are many challenges to the management of CRS especially in the case of the more severe and refractory forms of disease. Therefore, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), a collaboration between EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus (ICON) on Chronic Rhinosinusitis. The purpose of this ICON on CRS is to highlight the key common messages from the existing guidelines, the differences in recommendations as well as the gaps in our current knowledge of CRS, thus providing a concise reference. In this document we discuss the definition of the disease, its relevance, pharmacoeconomics, pathophysiology, phenotypes and endotypes, genetics and risk factors, natural history and co-morbidities as well as clinical manifestations and treatment options in both adults and children comprising pharmacotherapy, surgical interventions and more recent biological approaches. Finally, we have also highlighted the unmet needs that wait to be addressed through future research.

Advances in asthma drug discovery: evaluating the potential of nasal cell sampling and beyond

INTRODUCTION

Inhaled corticosteroid anti-inflammatory therapy is effective at controlling disease symptoms of asthma, but a subset of patients remains symptomatic despite optimal treatment, creating a clear unmet medical need. Moreover, none of the currently available drugs for asthma are really disease-modifying or curative. Although murine models of asthma, based on transgenic and knockout animals, may offer an integrated pathophysiological system for studying the characteristics of airway inflammation and hyperresponsiveness, these alterations are noteworthily different compared with those observed in asthmatic patients. Since a clear functional and inflammatory relationship between the nasal mucosa and bronchial tissue in patients suffering from asthma and allergic rhinitis has been recognized, using preclinical models based on human nasal cells sampling might support a prompt and effective anti-inflammatory drug discovery in asthma.

AREAS COVERED

The authors provide a review, which discusses the potential role of nasal cell sampling and its application in advanced drug discovery for asthma. The contents range from the similarities and differences between asthma and allergic rhinitis up to artificial airway models based on sophisticated human lung-on-a-chip devices.

EXPERT OPINION

Nasal cell sampling and processing have reached a great potential in asthma drug discovery. The authors believe that models of asthma, which are based on human nasal cells, can provide valuable indications of proof of pharmacological and potential therapeutic efficacy in both preclinical and early clinical settings.

Host-microbial interactions in patients with chronic rhinosinusitis

There has been considerable investigation of host-microbial interactions in patients with chronic rhinosinusitis (CRS) in hopes of elucidating mechanisms of disease and better treatment. Most attention has been paid to bacterial infection and potential underlying defects in innate immunity. Bacterial biofilm is present in most patients with CRS undergoing surgical intervention, and its presence is associated with more severe disease and worse surgical outcomes. A role for viral or fungal infection in patients with CRS is less clear. There is no evidence for a primary defect in mucociliary clearance in most patients with CRS. Decreased levels of certain antimicrobial proteins, most notably lactoferrin, have been found in sinus secretions, whereas levels of other antimicrobial proteins have been found to be normal. No primary defects in Toll-like receptors have been found in patients with CRS, although a 50% reduced expression of Toll-like receptor 9 was reported in patients with recalcitrant nasal polyps. A polymorphism in a bitter taste receptor was recently associated with refractory CRS and persistent Pseudomonas aeruginosa infection. A downregulation of innate immunity by maladaptive T_H2 tissue inflammation has also been described in patients with recalcitrant nasal polyps, suggesting a link to persistent infection. To date, an effective means of restoring host-microbial balance and mitigating disease in patients with CRS remains elusive.

Effects of sodium hyaluronate in children with recurrent upper respiratory tract infections: results of a randomised controlled study

Hyaluronic acid is a major component of many extracellular matrices that plays a role in the regulation of vasomotor tone and mucous gland secretion, and in the modulation of the inflammatory process in upper and lower airways. This pilot study was aimed at evaluating the effects of nasal washes with 9 mg nebulised sodium hyaluronate given for 15 days per month over 3 months in 75 paediatric patients with recurrent upper respiratory tract infections (URTI). Eligible patients were randomized to treatment with nasal washes containing 9 mg sodium hyaluronate plus saline solution or saline alone, according to an open-label, parallel group design, with blind observer assessment. Ciliary motility, which was assessed based on a 0-3 point rating scale (0 = absent, 1 = less than 5 minutes, 2 = greater than or equal to 5 and &#8804; 10 minutes, 3 = greater than 10 minutes) was the primary study endpoint. The secondary efficacy variables included cytological (presence of neutrophils, eosinophils and mast cells), microbiological (presence of bacteria and mycetes), endoscopical (presence of adenoid hypertrophy and biofilm) and clinical (presence of rhinitis, post-nasal drip, nasal dyspnoea) parameters. The two treatment groups (mean age 7.5 years, 53percent of males) were comparable for baseline data, except a higher mean age in the control group than in the treated group. Treatment with 9 mg sodium hyaluronate was associated with significantly greater improvements (p less than 0.001 between groups) in primary outcome ciliary motility [odds ratio (OR) 13.61; 95 percent CI 4.51-41.00 in the univariate regression analysis that examined the probability of improvement]. Treatment with 9 mg sodium hyaluronate was also significantly superior to saline alone in adenoid hypertrophy (p less than 0.001; OR 14.72; 95 percent CI 4.74-45.68), presence of bacteria (p = 0.026; OR 2.95; 95 percent CI 1.15-7.55), neutrophils (p = 0.002; OR 4.51; 95 percent CI 1.75-11.62), rhinitis (p = 0.040; OR 10.47; 95 percent CI 3.10-35.31), nasal dyspnoea (p = 0.047; OR 3.80; 95 percent CI 1.09-13.19) and biofilm (p = 0.049; OR 9.90; 95 percent CI 2.61-37.47). Advantages of 9 mg of sodium hyaluronate over control on post-nasal drip and presence of mycetes (although evident) did not reach the level of statistical significance. The superiority of the treated group over saline alone was confirmed in a multivariate logistic regression analysis that took into account age as confounding factor. The number of days of absence from school was significantly lower in the 9 mg sodium hyaluronate group compared to controls (p less than 0.001 between groups). A 3-month intermittent treatment with 9 mg sodium hyaluronate with nasal washes plus saline solution was associated with significant improvements in ciliary motility and in cytological, microbiological, endoscopic and clinical outcomes compared to saline, in children with recurrent URTI.

Abnormal nasal nitric oxide production, ciliary beat frequency, and Toll-like receptor response in pulmonary nontuberculous mycobacterial disease epithelium

RATIONALE

Pulmonary nontuberculous mycobacterial (PNTM) disease has increased over the past several decades, especially in older women. Despite extensive investigation, no consistent immunological abnormalities have been found. Using evidence from diseases such as cystic fibrosis and primary ciliary dyskinesia, in which mucociliary dysfunction predisposes subjects to high rates of nontuberculous mycobacterial disease that increase with age, we investigated correlates of mucociliary function in subjects with PNTM infections and healthy control subjects.

OBJECTIVES

To define ex vivo characteristics of PNTM disease.

METHODS

From 2009 to 2012, 58 subjects with PNTM infections and 40 control subjects were recruited. Nasal nitric oxide (nNO) was determined at the time of respiratory epithelial collection. Ciliary beat frequency at rest and in response to Toll-like receptor (TLR) and other agonists was determined using high-speed video microscopy.

MEASUREMENTS AND MAIN RESULTS

We found decreased nNO production, abnormally low resting ciliary beat frequency, and abnormal responses to agonists of TLR2, -3, -5, -7/8, and -9 in subjects with PNTM compared with healthy control subjects. The low ciliary beat frequency in subjects with PNTM was normalized ex vivo by augmentation of the NO-cyclic guanosine monophosphate pathway without normalization of their TLR agonist responses.

CONCLUSIONS

Impaired nNO, ciliary beat frequency, and TLR responses in PNTM disease epithelium identify possible underlying susceptibility mechanisms as well as possible avenues for directed investigation and therapy.

Purinergic signaling in the airways

Evidence for a significant role and impact of purinergic signaling in normal and diseased airways is now beyond dispute. The present review intends to provide the current state of knowledge of the involvement of purinergic pathways in the upper and lower airways and lungs, thereby differentiating the involvement of different tissues, such as the epithelial lining, immune cells, airway smooth muscle, vasculature, peripheral and central innervation, and neuroendocrine system. In addition to the vast number of well illustrated functions for purinergic signaling in the healthy respiratory tract, increasing data pointing to enhanced levels of ATP and/or adenosine in airway secretions of patients with airway damage and respiratory diseases corroborates the emerging view that purines act as clinically important mediators resulting in either proinflammatory or protective responses. Purinergic signaling has been implicated in lung injury and in the pathogenesis of a wide range of respiratory disorders and diseases, including asthma, chronic obstructive pulmonary disease, inflammation, cystic fibrosis, lung cancer, and pulmonary hypertension. These ostensibly enigmatic actions are based on widely different mechanisms, which are influenced by the cellular microenvironment, but especially the subtypes of purine receptors involved and the activity of distinct members of the ectonucleotidase family, the latter being potential protein targets for therapeutic implementation.

Acquired cilia dysfunction in chronic rhinosinusitis

BACKGROUND

Cilia are complex and powerful cellular structures of the respiratory mucosa that play a critical role in airway defense. Respiratory epithelium is lined with cilia that perform an integrated and coordinated mechanism called mucociliary clearance. Mucociliary clearance is the process by which cilia transport the mucus blanket overlying respiratory mucosa to the gastrointestinal tract for ingestion. It is the primary means by which the airway clears pathogens, allergens, debris, and toxins. The complex structure and regulatory mechanisms that dictate the form and function of normal cilia are not entirely understood, but it is clear that ciliary dysfunction results in impaired respiratory defense.

METHODS

A literature review of the current knowledge of cilia dysfunction in chronic rhinosinsusitis was conducted.

RESULTS

Ciliary dysfunction may be primary, the result of genetic mutations resulting in abnormal cilia structure, or, more commonly, secondary, the result of environmental, infectious, or inflammatory stimuli that disrupt normal motility or coordination. Patients with chronic rhinosinusitis (CRS) have been found to have impaired mucociliary clearance. Many biochemical, environmental, and mechanical stimuli have been shown to influence ciliary beat frequency, and common microbial pathogens of respiratory mucosa such as Pseudomonas aeruginosa and Haemophilus influenzae have developed toxins that appear to interrupt normal mucociliary function. Furthermore, inflammatory mediators known to be present in patients with CRS appear to impair secondarily mucociliary clearance.

CONCLUSION

The goal of this article is to summarize the recent developments in the understanding of cilia dysfunction and mucociliary clearance in CRS.

Molecular modulation of airway epithelial ciliary response to sneezing

Our purpose was to evaluate the effect of the mechanical force of a sneeze on sinonasal cilia function and determine the molecular mechanism responsible for eliciting the ciliary response to a sneeze. A novel model was developed to deliver a stimulation simulating a sneeze (55 mmHg for 50 ms) at 26°C to the apical surface of mouse and human nasal epithelial cells. Ciliary beating was visualized, and changes in ciliary beat frequency (CBF) were determined. To interrogate the molecular cascades driving sneeze-induced changes of CBF, pharmacologic manipulation of intra- and extracellular calcium, purinergic, PKA, and nitric oxide (NO) signaling were performed. CBF rapidly increases by ≥150% in response to a sneeze, which is dependent on the release of adenosine triphosphate (ATP), calcium influx, and PKA activation. Furthermore, apical release of ATP is independent of calcium influx, but calcium influx and subsequent increase in CBF are dependent on the ATP release. Lastly, we observed a blunted ciliary response in surgical specimens derived from patients with chronic rhinosinusitis compared to control patients. Apical ATP release with subsequent calcium mobilization and PKA activation are involved in sinonasal ciliary response to sneezing, which is blunted in patients with upper-airway disease.

Cigarette Smoke Inhibits Dynamic Ciliary Beat Frequency in Pediatric Adenoid Explants

Objective. Environmental tobacco smoke exposure in children increases the incidence of upper respiratory infections, chronic sinusitis, and chronic otitis media. This study investigated the effects of ex vivo and in vitro smoke exposure on dynamic ciliary beat frequency (CBF) in pediatric adenoid explants.

Study Design. Blinded and controlled prospective study.

Setting. Tertiary care pediatric hospital.

Subjects and Methods. Fifty-five children undergoing adenoidectomy for obstructive sleep apnea and adenotonsillar hypertrophy were enrolled in this study. Adenoids were surgically removed using currettage. Hair was collected for nicotine analysis. Tissue was sectioned into 1-mm strips and allowed to equilibrate in DMEM/F12 with 2% fetal bovine serum for 24 hours. Cilia-bearing explant tissues were treated with either DMEM/F12 media, 5% cigarette smoke extract (CSE), or 10% CSE for 24 hours. Cilia were then stimulated using either isoproterenol (10−9 M) or methacholine (10−6M), and CBF was serially recorded using the Sisson-Ammons Video Analysis (SAVA) software.

Results. Children with hair nicotine levels ≥1 ng/mg consistent with secondhand smoke exposure display blunted dynamic CBF response ex vivo. Explants incubated with CSE in vitro demonstrate significant impairment of isoproterenol and methacholine-induced CBF.

Conclusion. CBF of adenoid explants increases when stimulated with isoproterenol and methacholine. Ex vivo and in vitro smoke exposure blunted ciliostimulation of CBF in adenoid explants. Smoke exposure impairs ciliary function in the pediatric airway and could potentially contribute to disorders such as chronic rhinosinusitis and chronic otitis media.

The effect of histamine on ciliary beat frequency in the acute phase of allergic rhinitis

BACKGROUND

There have been few studies about the effect of histamine on ciliary beat frequency (CBF) in the acute phase of allergic rhinitis.

OBJECTIVE

The present study was designed to investigate CBF in the acute phase of allergic rhinitis and the effect of histamine on CBF.

MATERIALS AND METHODS

Nasal septal mucosae were obtained from 13 mice that had been systemically immunized and locally challenged with ovalbumin (OVA) (group A), 11 OVA immunized and phosphate-buffered saline-challenged mice (group B), and 12 nontreated negative control mice (group C). The CBFs were observed within 20 minutes of local challenge with OVA. Ciliary beat frequencies were measured before and after treatment with 10(-5), 10(-3), and 10(-1) mol/L histamine and after administering antihistamine or Dulbecco's modified Eagle's medium to histamine-exposed mucosa.

RESULTS

The baseline CBF in group A was higher than in groups B and C. After treatment with 10(-1) mol/L histamine, CBF in all groups decreased to 0 within 5 to 7 minutes, whereas treatment with 10(-5) or 10(-3) mol/L histamine had no effect. The application of 100 μmol/L fexofenadine or Dulbecco's modified Eagle's medium solution restored histamine-induced ciliostasis to near baseline CBF after 10 minutes.

CONCLUSIONS

Ciliary beat frequency increased in the acute phase of a mouse model of allergic rhinitis. Physiologic concentrations of histamine had no effect on CBF, and thus, it appears that other mechanisms control CBF in the acute phase of allergic rhinitis.

Cilia dysfunction

Cilia are complex and powerful cellular structures that serve a multitude of functions across many types of organisms. In humans, one of the most critical roles of cilia is defense of the airway. The respiratory epithelium is lined with cilia that normally carry out an integrated and coordinated mechanism called mucociliary clearance. Mucociliary clearance, the process by which cilia transport the viscous mucus blanket of the upper airway to the gastrointestinal tract, is the primary means by which the upper airway clears itself of pathogens, allergens, debris, and toxins. The complex structure and regulatory mechanisms that dictate the form and function of normal cilia are not entirely understood, but it is clear that ciliary dysfunction results in impaired respiratory defense. Ciliary dysfunction may be primary, the result of genetic mutations resulting in abnormal cilia structure, or secondary, the result of environmental, infectious or inflammatory stimuli that disrupt normal motility or coordination.

Innate immunity

Innate immunity is an exciting area of research in rhinology because emerging evidence suggests that abnormal local immune responses, rather than pathogen-specific adaptive immunity, may play a more important role in the pathogenesis of chronic rhinosinusitis (CRS). This article reviews important recent research regarding the innate immune system and CRS, with particular focus on the role of pattern recognition receptors, antimicrobial peptides and biofilms, epithelial ciliary function, cystic fibrosis, and cigarette smoking, and on areas for future research and therapy.

Epithelium, cilia, and mucus: their importance in chronic rhinosinusitis

Chronic rhinosinusitis is a common disease resulting from inflammation of the sinonasal mucosa. It has long been recognized that patients with chronic rhinosinusitis have impaired capacity to clear sinonasal secretions. However, the cause of this pathologic process is not well understood. In this article the components of mucociliary clearance, including cilia, mucus production, and cilia beat frequency, are reviewed and alterations of the system discussed regarding contribution to the disease process.

Screening for staphylococcal superantigen genes shows no correlation with the presence or the severity of chronic rhinosinusitis and nasal polyposis

BACKGROUND

Staphylococcus aureus secretes numerous exotoxins which may exhibit superantigenic properties. Whereas the virulence of several of them is well documented, their exact biological effects are not fully understood. Exotoxins may influence the immune and inflammatory state of various organs, including the sinonasal mucosa: their possible involvement in chronic rhinosinusitis has been suggested and is one of the main trends in current research. The aim of this study was to investigate whether the presence of any of the 22 currently known staphylococcal exotoxin genes could be correlated with chronic rhinosinusitis.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a prospective, multi-centred European study, analysing 93 Staphylococcus aureus positive swabs taken from the middle meatus of patients suffering from chronic rhinosinusitis, with or without nasal polyposis, and controls. Strains were systematically tested for the presence of the 22 currently known exotoxin genes and genotyped according to their agr groups. No direct correlation was observed between chronic rhinosinusitis, with or without nasal polyposis, and either agr groups or the presence of the most studied exotoxins genes (egc, sea, seb, pvl, exfoliatins or tsst-1). However, genes for enterotoxins P and Q were frequently observed in nasal polyposis for the first time, but absent in the control group. The number of exotoxin genes detected was not statistically different among the 3 patient groups.

CONCLUSIONS/SIGNIFICANCE

Unlike many previous studies have been suggesting, we did not find any evident correlation between staphylococcal exotoxin genes and the presence or severity of chronic rhinosinusitis with or without nasal polyposis.

Cytology of the nasal mucosa after total laryngectomy

CONCLUSION

This study demonstrates morphological changes in the nasal mucosa as a consequence of functional changes of the nasal cavity after total laryngectomy (TLE).

OBJECTIVE

Observation of the changes of the nasal mucosa in patients after TLE.

PATIENTS AND METHODS

A cohort observational study contained 30 patients after TLE. These patients underwent nasal endoscopy and cytological and microbiological examination of the nasal mucosa. The control group comprised 30 patients.

RESULTS

In patients who underwent TLE, morphological changes occurred in the nasal mucosa. The hyperplasia of the cells in the basal zone was the most remarkable change after TLE. The difference was statistically significant (p=0.0002) in comparison with the control group. No statistically significant difference was shown in the incidence of squamous cell metaplasia. The inflammatory changes in the nasal mucosa were found in only 10% of patients after TLE; in comparison with the control group the statistically significant decrease was proven (p=0.003). The presence of bacteria in the nasal mucosa without any signs of inflammation was demonstrated in 27% of the patients who underwent TLE. That finding was not seen in the control group. The statistically significant difference was demonstrated (p=0.0046).

Evaluation of nasal mucociliary clearance after medical or surgical treatment of chronic rhinosinusitis

An evaluation of mucociliary clearance, with the use of rhinoscintigraphy and other objectives and subjectives measures, in medically and surgically treated patients with chronic rhinosinusitis, as well in patients with or without nasal polyposis, can add to the understanding of ciliary function and its role in the pathogenesis of chronic rhinosinusitis. Thirty-four patients medically treated and 21 surgically treated (FESS) patients evaluated with rhinoscintigraphy, CT-scans, and SNOT-20. Nine of the surgically treated patients had nasal polyps and studied as a separate group. Although the various groups differ on Lund-Mackay scores (H = 11.659, P = 0.003) and SNOT-20 results (F = 26.904, P < 0.001), a statistically significant difference between mucociliary transport velocity (MTV) values could not be found. Moreover, multiple linear regression could not prove a statistically significant correlation between MTV and other variables. The various groups of chronic rhinosinusitis patients cannot be differentiated on the basis of possible nasal mucociliary clearance alternations.