Wound healing in endoscopic sinus surgery: Phase 1 clinical trial evaluating the role of Chitogel with adjuvants.

OBJECTIVES: This study aimed to determine the safety and efficacy of Chitogel, with and without Deferiprone (Def) and Gallium Protoporphyrin (GaPP), as a promoter of wound healing to improve surgical outcomes after endoscopic sinus susgery. DESIGN: A double-blinded, randomised control human clinical trial was conducted in patients undergoing ESS as a treatment for chronic rhinosinusitis. Participants underwent functional ESS or FESS with drill out as required and were randomised to receive test product Chitogel, Chitogel in combination with Def or Def-GaPP versus no packing (control). SETTING: Ostial stenosis and persistent inflammation are the main reasons for revision endoscopic sinus surgery (ESS). Post-operative (PO) dressings can improve PO wound healing and patient outcomes after ESS. PARTICIPANTS: Eighty two patients were included in this study with 79 patients completing the study with 40 undergoing full house FESS and 39 FESS plus frontal drillout. MAIN OUTCOME MEASURES: Patients were followed up at 2, 6 and 12 weeks PO, and outcome scores such as SNOT-22, VAS and LKS, pre and post-surgery (12 weeks) were compared. RESULTS: Seventy nine patients completed the study, there was a significant reduction in SNOT-22 score and improvement of VAS at 12 weeks in patients treated with Chitogel compared to control (p < .05). In those patients, the mean ostium area for the Chitogel and the Chitogel + Def + GaPP groups was higher across all three sinuses compared to the no-treatment control group, without statistical significance. Sphenoid sinus ostium was significantly more patent in patients treated with Chitogel compared to the control at the 12-week time point (p < .05). CONCLUSION: Chitogel as a PO dressing after ESS results in the best patient-reported symptom scores and objective measurements. The combination of Def and GaPP to Chitogel though proving safe, had no effect on the ostium patency or mucosal healing.

Customised acoustic therapy delivered through a web-based platform-An innovative approach to tinnitus treatment.

OBJECTIVES: Customised acoustic therapy aims to moderate the neural pathways implicated in the pathophysiology of tinnitus. This study aimed to assess the efficacy of customised acoustic therapy administered via a web-based treatment platform. DESIGN: Clinical trial with prospective recruitment. Fifty-eight participants underwent 6 weeks of customised acoustic therapy. SETTING: Treatment was delivered for 2 h each day using a smartphone, tablet or computer. Treatment was integrated into usual daily activities. PARTICIPANTS: Participants with subjective tinnitus were recruited through public and private otolaryngology clinics and electronic and print media. MAIN OUTCOMES MEASURED: FiveQ, a novel 5 question tinnitus questionnaire, was measured at baseline and each week of treatment. Statistical analyses, including Wilcoxon, Mann-Whitney and mixed linear regression, were used to assess treatment efficacy and identify factors associated with treatment response. RESULTS: 39/58 participants (67.2%) had an improvement in symptom severity scores, 4 had no change (6.9%) and 15 had a decline from baseline (25.9%). Mean FiveQ scores improved by 22.9% from 40.8 (SD = 21.4) at baseline to 31.5 (SD = 21.3) following 6 weeks of treatment (p < 0.001). With the exception of the slight tinnitus group, all other groups (from mild to catastrophic) demonstrated a treatment response. Participants with low frequency tinnitus (<2000 Hz) had a significantly greater treatment response (p < 0.001). CONCLUSION: Customised acoustic therapy administered via a web-based platform demonstrated encouraging efficacy. At least mild symptoms at baseline and low frequency tinnitus were associated with a greater treatment response. Customised acoustic therapy offers accessible and efficacious tinnitus treatment, however longer term clinical studies are required to confirm the observed initial benefit is maintained.

FiveQ: A new easy-to-use validated clinical instrument for tinnitus severity.

OBJECTIVES: Tinnitus is a complex and debilitating phenomenon with potentially significant implications on quality of life. New presentations can be resource and time intensive for clinicians. Validated comprehensive tinnitus questionnaires may lack practical utility in the high-volume clinical setting. Concise, targeted questionnaires may offer an efficient alternative. This study aimed to assess the validity of the FiveQ, a novel five question construct designed to measure tinnitus severity. Convergent validity was assessed through correlating FiveQ against two comprehensive validated questionnaires, the Tinnitus Handicap Questionnaire (THQ) and Tinnitus Handicap Inventory (THI). DESIGN: Cross-sectional study with prospective recruitment. The 117 voluntarily recruited participants completed the FiveQ, THI and THQ questionnaires. Results were comparatively analysed. SETTING: Recruitment was via electronic and print media, audiology clinics and public and private otolaryngology outpatient clinics. Surveys were completed electronically. PARTICIPANTS: Members of the public aged over 18 with subjective tinnitus were invited to participate. MAIN OUTCOME MEASURED: Analyses for establishing the content validity, construct validity, internal consistency, explorary factor analysis, and responsiveness of FiveQ was performed. RESULTS: FiveQ demonstrated a high positive correlation with both the THI (r = 0.773, p < .001) and THQ (r = 0.808, p < .001). Internal consistency for FiveQ reached an acceptable threshold (Cronbach's alpha 0.86). Exploratory factor analysis demonstrated that one latent factor underlies the five items of the FiveQ. FiveQ demonstrated better responsiveness than both the THI and THQ after a 6 week interval repeat measurement. CONCLUSION: FiveQ demonstrated high-positive correlations with existing validated tinnitus questionnaires as well as acceptable internal consistency and factor analysis. The concise construct of FiveQ allows clinicians to efficiently estimate tinnitus severity, target treatment towards dominant symptoms and establish a reliable estimation of treatment response following interventions.

Prevention of adhesions post-abdominal surgery: Assessing the safety and efficacy of Chitogel with Deferiprone in a rat model.

INTRODUCTION: Adhesions are often considered to be an inevitable consequence of abdominal and pelvic surgery, jeopardizing the medium and long-term success of these procedures. Numerous strategies have been tested to reduce adhesion formation, however, to date, no surgical or medical therapeutic approaches have been successful in its prevention. This study demonstrates the safety and efficacy of Chitogel with Deferiprone and/or antibacterial Gallium Protoporphyrin in different concentrations in preventing adhesion formation after abdominal surgery. MATERIALS AND METHODS: 112 adult (8-10 week old) male Wistar albino rats were subjected to midline laparotomy and caecal abrasion, with 48 rats having an additional enterotomy and suturing. Kaolin (0.005g/ml) was applied to further accelerate adhesion formation. The abrasion model rats were randomized to receive saline, Chitogel, or Chitogel plus Deferiprone (5, 10 or 20 mM), together with Gallium Protoporphyrin (250µg/mL). The abrasion with enterotomy rats were randomised to receive saline, Chitogel or Chitogel with Deferiprone (1 or 5 mM). At day 21, rats were euthanised, and adhesions graded macroscopically and microscopically; the tensile strength of the repaired caecum was determined by an investigator blinded to the treatment groups. RESULTS: Chitogel with Deferiprone 5 mM significantly reduced adhesion formation (p<0.01) when pathologically assessed in a rat abrasion model. Chitogel with Deferiprone 5 mM and 1 mM also significantly reduced adhesions (p<0.05) after abrasion with enterotomy. Def-Chitogel 1mM treatment did not weaken the enterotomy site with treated sites having significantly better tensile strength compared to control saline treated enterotomy rats. CONCLUSIONS: Chitogel with Deferiprone 1 mM constitutes an effective preventative anti-adhesion barrier after abdominal surgery in a rat model. Moreover, this therapeutic combination of agents is safe and does not weaken the healing of the sutured enterotomy site.

Proteomic analysis of nasal mucus samples of healthy patients and patients with chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis (CRS) has a complex and multifactorial pathogenesis with a heterogeneous inflammatory profile. Proteomic analysis of nasal mucus may enable further understanding of protein abundances and biologic processes present in CRS and its endotypes compared with in healthy patients. OBJECTIVE: Our aim was to determine differences in the nasal mucus proteome of healthy patients and patients with CRS. METHODS: Nasal mucus was obtained from healthy patients, patients with CRS without nasal polyps (CRSsNP), and patients with CRS with nasal polyps (CRSwNP) before surgery. Gel electrophoresis was performed to fractionate the complex protein extracts before mass spectrometry analysis. Gene set enrichment analysis was performed on differentially expressed proteins. RESULTS: A total of 33 patients were included in this study (12 healthy, 10 with CRSsNP, and 11 with CRSwNP). In all, 1142 proteins were identified in mucus samples from healthy patients, 761 in mucus samples from patients with CRSsNP, and 998 in mucus samples from patients with CRSwNP. Dysfunction in immunologic pathways, reduced cellular signaling, and increased cellular metabolism with associated tissue remodeling pathways were present in patients with CRS compared with in healthy patients. CONCLUSION: Significant downregulation of mucosal immunity and antioxidant pathways with increased tissue modeling processes may account for the clinical manifestations of CRS. Ultimately, the differing proteome and biologic processes provide further insight into CRS pathogenesis and its endotypes.

Staphylococcus aureus biofilm exoproteins are cytotoxic to human nasal epithelial barrier in chronic rhinosinusitis.

BACKGROUND: Chronic rhinosinusitis patients (CRS) suffer from chronic inflammation of the sinus mucosa associated with chronic relapsing infections. Mucosal biofilms, associated with Staphylococcus aureus, have been implicated as a cause. We compared the effect of exoproteins secreted from clinical isolates of S aureus from CRS patients in planktonic and biofilm form on the nasal epithelial barrier. METHODS: Clinical S aureus isolates from 39 CRS patients were grown in planktonic and biofilm forms and their exoproteins concentrated. These were applied to primary human nasal epithelial cells grown at the air-liquid interface. Transepithelial electrical resistance, permeability of flourescein isothiocyanate-dextrans, and cytotoxicity were measured. Structure and expression of tight junctions zona occludens-1, and claudin-1 proteins were assessed by electron microscopy and immunofluorescence. The Wilcoxon signed rank test was used for statistical analyses. RESULTS: S aureus biofilm exoproteins showed dose- and time-dependent reduction of transepithelial electrical resistance, increased cell toxicity, and increased permeability (p < 0.001) compared with equal concentrations of planktonic cultures. Discontinuity in zona occludens-1 and claudin-1 immunofluorescence was confirmed as disrupted tight junctions on electron microscopy. CONCLUSION: S aureus biofilm exoproteins disrupt the mucosal barrier structure in a time- and dose-dependent manner and are toxic. Damage to the mucosal barrier by S aureus biofilm exoproteins may play a major role in CRS etiopathogenesis.

Microbiotyping the Sinonasal Microbiome.

This study offers a novel description of the sinonasal microbiome, through an unsupervised machine learning approach combining dimensionality reduction and clustering. We apply our method to the International Sinonasal Microbiome Study (ISMS) dataset of 410 sinus swab samples. We propose three main sinonasal "microbiotypes" or "states": the first is Corynebacterium-dominated, the second is Staphylococcus-dominated, and the third dominated by the other core genera of the sinonasal microbiome (Streptococcus, Haemophilus, Moraxella, and Pseudomonas). The prevalence of the three microbiotypes studied did not differ between healthy and diseased sinuses, but differences in their distribution were evident based on geography. We also describe a potential reciprocal relationship between Corynebacterium species and Staphylococcus aureus, suggesting that a certain microbial equilibrium between various players is reached in the sinuses. We validate our approach by applying it to a separate 16S rRNA gene sequence dataset of 97 sinus swabs from a different patient cohort. Sinonasal microbiotyping may prove useful in reducing the complexity of describing sinonasal microbiota. It may drive future studies aimed at modeling microbial interactions in the sinuses and in doing so may facilitate the development of a tailored patient-specific approach to the treatment of sinus disease in the future.

A Novel Rat Model to Test Intra-Abdominal Anti-adhesive Therapy.

Background: Adhesion formation after abdominal surgery is considered almost inevitable and a major cause of morbidity. Novel treatments have been proposed, however there is a lack of suitable small animal models for pre-clinical evaluation, mainly due to inconsistency in adhesion formation in positive control animals. Here, we propose a new rat model of abdominal adhesions using Kaolin as the adhesion-inducing agent at an optimized dosage for testing newer agents in respect to their anti-adhesive property. Materials and Methods: Twenty-five adult (8-10 week old) male Wistar albino rats underwent midline laparotomy and caecal abrasion and were randomized to receive topical applications of normal saline or different concentrations and volumes of a Kaolin-based formulation. At day 14 rats were humanely killed, and adhesions graded macroscopically by an investigator blinded to the treatment groups, using pre-determined adhesion scores and microscopically using histopathology. Results: Kaolin at 0.005 g/mL caused consistent adhesions without compromising rat viability. At higher doses significant morbidity and mortality was observed in the animals treated. Conclusions: Kaolin induced adhesion in a rat abdominal surgery model is reliable and can be safely used to test the efficacy of novel anti-adhesive formulations to prevent intra-abdominal adhesions.

Antibiotics Affect ROS Production and Fibroblast Migration in an In-vitro Model of Sinonasal Wound Healing.

Introduction: Antibiotics are often administered to patients perioperatively and have been shown to affect ROS production of nasal cells in vitro, but their effect in the setting of active wound healing remains unclear. Reactive oxygen species (ROS) are known to play a significant role in wound healing. This study analyzed a broad array of antibiotics used after sinus surgery to assess their effect on wound healing and ROS production in vitro. It was hypothesized that ROS production would be affected by these antibiotics and there would be a negative relationship between ROS activity and cell migration speed. Methods: Monolayers of primary human nasal epithelial cells (HNEC) and primary fibroblasts were disrupted with a linear wound, treated with 10 different antibiotics or a ROS inhibitor and observed over 36 h in a controlled environment using confocal microscopy. ROS activity and migration speed of the wound edge were measured at regular intervals. The relationship between the two parameters was analyzed using mixed linear modeling. Results: Performing a linear scratch over the cell monolayers produced an immediate increase in ROS production of ~35% compared to unscratched controls in both cell types. Incubation with mitoquinone and the oxazolidinone antibiotic linezolid inhibited ROS activity in both fibroblasts and HNEC in association with slowed fibroblast cell migration (p < 0.05). Fibroblast cell migration was also reduced in the presence of clarithromycin and mupirocin (p < 0.05). A significant correlation was seen between ROS suppression and cell migration rate in fibroblasts for mitoquinone and all antibiotics except for azithromycin and doxycycline, where no clear relationship was seen. Treatments that slowed fibroblast cell migration compared to untreated controls showed a significant correlation with ROS suppression (p < 0.05). Conclusion: Increased ROS production in freshly wounded HNEC and fibroblast cell monolayers was suppressed in the presence of antibiotics, in correlation with reduced fibroblast cell migration. In contrast, HNEC cell migration was not significantly affected by any of the antibiotics tested. This differential effect of antibiotics on fibroblast and HNEC migration might have clinical relevance by reducing adhesion formation without affecting epithelial healing in the postoperative setting.

The international sinonasal microbiome study: A multicentre, multinational characterization of sinonasal bacterial ecology.

The sinonasal microbiome remains poorly defined, with our current knowledge based on a few cohort studies whose findings are inconsistent. Furthermore, the variability of the sinus microbiome across geographical divides remains unexplored. We characterize the sinonasal microbiome and its geographical variations in both health and disease using 16S rRNA gene sequencing of 410 individuals from across the world. Although the sinus microbial ecology is highly variable between individuals, we identify a core microbiome comprised of Corynebacterium, Staphylococcus, Streptococcus, Haemophilus and Moraxella species in both healthy and chronic rhinosinusitis (CRS) cohorts. Corynebacterium (mean relative abundance = 44.02%) and Staphylococcus (mean relative abundance = 27.34%) appear particularly dominant in the majority of patients sampled. Amongst patients suffering from CRS with nasal polyps, a statistically significant reduction in relative abundance of Corynebacterium (40.29% vs 50.43%; P = .02) was identified. Despite some measured differences in microbiome composition and diversity between some of the participating centres in our cohort, these differences would not alter the general pattern of core organisms described. Nevertheless, atypical or unusual organisms reported in short-read amplicon sequencing studies and that are not part of the core microbiome should be interpreted with caution. The delineation of the sinonasal microbiome and standardized methodology described within our study will enable further characterization and translational application of the sinus microbiota.

Prevention of peridural adhesions in spinal surgery: Assessing safety and efficacy of Chitogel with Deferiprone in a sheep model.

INTRODUCTION: Spinal laminectomy is a common procedure performed to relieve neural compression in patients suffering from myelopathy or radiculopathy. However, up to 40% of patients suffer from persistent post-operative pain and disability, a condition known as Failed Back Surgery Syndrome (FBSS). Excessive scarring in the surgical bed is implicated as a cause. Hydrogels have been proposed to prevent adhesion formation post-laminectomy; however, their efficacy has not been proven. This study uses Chitogel complexed with the iron chelator Deferiprone (Def) to prevent adhesion formation in a sheep laminectomy model. MATERIAL & METHODS: Fifteen Adult Merino sheep (Ovis Aries, 1-5 yrs old) underwent laminectomy at lumbar levels 1-5 and had hydrated aluminum silicate (kaolin) applied to promote adhesion formation. Subjects were randomised to receive at each laminectomy level no-treatment control, Chitogel, Chitogel with Def at 20 mM or 40 mM or Carboxy-methyl-cellulose and Polyethylene oxide (CMC/PEO) gel. The animals were recovered for 3 months post-surgery, followed by assessment with Magnetic Resonance Imaging (MRI) and histopathology of the spinal tissues for evaluating the presence and extent of adhesions. RESULTS: MRI and Histology assessment indicated that Kaolin induced severe inflammation with adhesion formation. Chitogel with and without 20 mM Def decreased inflammation (p < 0.01) and trended to reduce adhesions (p < 0.1). Chitogel with Def 40 mM was not significantly dis-similar to CMC/PEO and did not reduce inflammation or adhesions compared to no-treatment control. CONCLUSION: Chitogel in combination with Def 20 mM is safe and effective in decreasing the inflammatory process and may possibly reduce post-operative adhesions following laminectomy.

The Microbiome of the Nasolacrimal System and Its Role in Nasolacrimal Duct Obstruction.

PURPOSE: Acquired nasolacrimal duct obstruction (NLDO) is a common problem leading to epiphora, the pathophysiology of which remains unclear. Culture-based studies have found Staphylococcal species to be the most prevalent organisms, reported in 47% to 73% of patients with NLDO. Recently, culture-independent molecular methods of have allowed more comprehensive detailing of local microbiota. This study aims to evaluate the sinonasal and lacrimal microbiome of patients undergoing dacryocystorhinostomy for NLDO using 16S-amplicon sequencing. METHODS: Guarded intraoperative swabs were taken from the middle meatus (MM), inferior meatus, and the opened lacrimal sac of 14 NLDO patients undergoing dacryocystorhinostomy and from the inferior meatus and MM on the contralateral unaffected side. MM swabs from 12 control patients were compared with NLDO patients. RESULTS: Comparing microbiota at lacrimal sac to MM and inferior meatus sites reveals that the lacrimal sac microbiome is dominated by Staphylococci (36.3%) and Corynebacterium (35.8%). No significant genus differential abundance between the 3 sites, and between the ipsilateral and contralateral sinonasal swabs, and no convincing evidence of reduced alpha diversity in all comparisons. There was a statistically significant lower relative abundance of Corynebacterium (37.6% vs. 65.1%; p = 0.035) in the MM of NLDO patients compared with controls. CONCLUSIONS: The lacrimal sac microbiome in acquired NLDO is similar to the sinonasal microbiome. The relative abundance of Corynebacterium was reduced compared with controls. These findings suggest that an altered sinonasal microbiome may be associated with NLDO, either as a consequence or a risk factor, and merits future research.The authors have demonstrated a decreased relative abundance of Corynebacterium at the middle meatus of patients with ipsilateral nasolacrimal duct obstruction (NLDO), compared with controls, and that the lacrimal sac microbiome is similar to the sinonasal microbiome. An altered microbial state may, therefore, be associated with NLDO, either as a consequence or a risk factor, and merits future research.

The effect of neutrophil serine proteases on human nasal epithelial cell barrier function.

BACKGROUND: The neutrophil serine proteases neutrophil elastase (NE), cathepsin G (CG), and proteinase 3 (PR3) are implicated in the regulation of inflammatory conditions. Pseudomonas aeruginosa elastase (PE), also a serine protease, has been found to behave similarly to NE and has been proposed to assist the pathogen in evading the host immune response. The effect of serine proteases on human nasal epithelial barrier function requires further investigation to better understand the pathophysiology of inflammatory conditions. METHODS: Purified human neutrophil serine proteases and PE were applied to primary human nasal epithelial cells grown at air-liquid interface (HNEC-ALI) cultures from 6 patients. Barrier integrity and function was assessed via transepithelial electrical resistance (TER), permeability assays, immunofluorescence of Zona occludens-1 (ZO-1), and ciliary beat frequency (CBF) measurements. Cytotoxicity assays were employed to assess cell viability. Interleukin 6 (IL-6) and IL-8 enzyme-linked immunosorbent assay (ELISA) assessed cytokine release from HNEC-ALI. RESULTS: The application of serine proteases showed detrimental effects on HNEC-ALI barrier integrity. Reduction in TER occurred with NE, CG, and PE with increased paracellular permeability with NE, CG, PR3, and PE. Discontinuous tight junctions with reduction in ZO-1 expression were identified using immunofluorescence. Neutrophil serine proteases were not toxic cells to the HNECs and had no detrimental effects on the CBF. CONCLUSION: Serine proteases derived from neutrophils and from P. aeruginosa showed detrimental effects on the mucosal barrier integrity with increased permeability, allowing for potential bacterial invasion. This finding may further assist in understanding the pathophysiology present in chronic inflammatory airway diseases.

Extent of maxillary sinus surgery and its effect on instrument access, irrigation penetration, and disease clearance.

BACKGROUND: Middle meatal antrostomy (MMA) provides limited access to the anteromedial and inferior aspect of the maxillary sinus (MS) often resulting in residual disease and inflammatory burden. Newer extended procedures, such as mega-antrostomy (Mega-A) and extended modified mega-antrostomy (EMMA), have been developed to address this limitation. This study assesses the effect of varying extent of MS surgery on irrigation penetration and access of instrumentation. METHODS: The MS of 5 fresh-frozen cadavers were sequentially dissected. Irrigation was evaluated with a squeeze bottle (SB) in different head positions and using different volumes of fluid. Surgical reach and visualization were examined using common sinus instruments and different angled endoscopes. A disease simulation was also performed to check for residual debris after instrumentation and irrigations. RESULTS: Irrigation penetration improved as antrostomy size increased (p < 0.0001), with a significant difference observed between the extended procedures and MMA. The effect of the volume was significant for SB (p < 0.0001) but head positions appeared irrelevant (p = 0.613). Overall visualization improved for Mega-A and EMMA. A similar trend was seen for the reach of the instruments to all sinus wall subsites. EMMA facilitated the most removal of "sinus disease" in the disease simulation model when compared with both MMA and Mega-A, due to its reach of the anteroinferior aspects of the maxillary sinus. CONCLUSIONS: High-volume irrigation using SB achieved good sinus penetration, irrespective of head position. Extended MS procedures appear to further increase irrigation penetration as well as surgical access.

The Association Between Disease Severity and Microbiome in Chronic Rhinosinusitis.

OBJECTIVE: The role of the microbiome in the etiology of chronic rhinosinusitis (CRS) is still in debate. Reductions in richness and diversity have been implicated in CRS; however, limited knowledge exists regarding the impact of the severity of disease on the microbiome. The associations between constituents of the microbiome and the degree of mucosal inflammation and tissue eosinophilia are described. METHODS: A cross-sectional study of CRS and non-CRS patients who underwent endoscopic sinus surgery was performed. Sinus mucosal biopsies were assessed for the degree of inflammation and tissue eosinophilia. Middle-meatal swabs were subjected to 16S rRNA gene sequencing, which quantified the prevalence, mean relative abundance, richness, and diversity. Comparisons between the microbiome at the genus level and degree of inflammation (absent, mild, moderate, severe) and tissue eosinophilia (absent, < 10, 10-100, > 100 per high-powered field) were performed. RESULTS: Eight-nine patients (52.8 ± 14.21 years, 64.0% male) were assessed. Of those, 52 had CRS and 37 were controls. Corynebacterium and Staphylococcus were the most abundant genera in both the CRS (29% and 16%) and non-CRS groups (40% and 20%). Richness decreased in more severely inflamed patients (23.2 ± 13.9 vs. 18.1 ± 16.1 vs. 16.8 ± 12.3 vs. 14.7 ± 10.9; P < 0.01), as did diversity (1.4 ± 0.7 vs. 1.2 ± 1.0 vs. 1.2 ± 0.8 vs. 0.9 ± 0.7; P = 0.05). Richness was associated with higher tissue eosinophilia (23.2 ± 13.9 vs. 19.3 ± 17.2 vs. 15.9 ± 11.6 vs. 13.4 ± 6.6; P < 0.01). CONCLUSION: The loss of richness and diversity seen in the CRS microbiome appears to be a product of severity of inflammation and tissue eosinophilia. Whether this dysbiosis is causative or a result of the disease with impaired epithelial integrity requires ongoing research. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1265-1273, 2019.

Comparative Viral Sampling in the Sinonasal Passages; Different Viruses at Different Sites.

Background: With the emergence of the microbiome as an important factor in health and disease in the respiratory tract standardised, validated techniques are required for its accurate characterisation. No standardised technique has been reported specifically for viral sampling in the sinonasal passages. Aim: To optimise viral sampling techniques from the sinonasal cavity. Methods: Sterile cytology brushes were used under endoscopic guidance to sample the sinonasal mucosa at time of endoscopic sinus surgery at both the middle and inferior meatuses (MM and IM). DNA and RNA were extracted from the samples and underwent PCR or RT-PCR testing, respectively, for a panel of 15 common upper respiratory tract viruses. Results: Twenty-four adult patients were recruited for this study. 18/24 (75%) patients were positive for virus in at least one site, while 8/24 (33%) were positive for virus at both sites. The mean number of viruses identified at the two sites were similar (0.875 ± 0.899 at the MM vs. 0.750 ± 1.032 at the IM). 6/24 (25%) of patients showed no virus at either site, while 3/24 (12.5%) demonstrated the same viral species at both sites. Conclusion: Although the number of viruses present at different sites with the nasal cavity are similar, discord exists in the viral species between sites. It is therefore recommended that both sites are sampled in the clinical and research setting better to characterise the viral species within the nasal cavity.