The histological and microbiological characteristics of bacterial microcolonies in paediatric tonsillar hyperplasia.

INTRODUCTION: Paediatric tonsillar hyperplasia (TH) is associated with a spectrum of presentations ranging from recurrent tonsillitis (RT) to sleep-disordered breathing (SDB). The underlying pathogenesis of tonsillar hyperplasia remains poorly understood. Previous studies have implicated bacterial microcolonies as targets of host inflammatory cells and as a potential driver of the chronic inflammation seen in TH. The role of atopy in tonsillar hyperplasia is also largely unknown. In this study, we aimed to determine the allergic responses and microbial factors that may influence TH in children. MATERIALS AND METHODS: Paired tonsils and a serum sample were collected from 21 children undergoing tonsillectomy for RT or SDB in the Auckland region. The disposition of immunoglobulin isotypes (IgG, A, M and E) and local inflammatory cells on histological sections of tonsil tissue were determined using immunohistochemistry techniques. Aeroallergen specific IgE (sIgE) and Staphylococcal enterotoxin C specific IgE (SEC-specific IgE) were measured in serum and tonsil tissue using the ImmunoCAP® system. Finally, tonsil bacterial microcolonies were then excised from histological slides using laser microdissection techniques, before undergoing bacterial and fungal amplicon sequencing. RESULTS: There were no significant differences in any of the measured variables between children with RT and SDB symptoms. IgE staining was not associated with increased levels of mast cells, leukocytes or plasma cells. However, sIgE positivity was more frequently found in local tissue than in serum (p = 0.025). A significant association was observed between tissue sIgE levels and tissue SEC-specific IgE levels (r2 = 0.95, p = 0.0001). The most abundant bacterial and fungal genera identified in the microcolonies were Fusobacterium, Sphingomonas, Porphyromonas, Prevotella and Malassezia. DISCUSSION: These results suggest that there is a local IgE response in children with TH. Local IgE production is unrelated to systemic atopy and may play a key role in the pathogenesis of TH. This is the first study to determine the microbial composition of microcolonies in tonsil tissue. These findings enhance current understanding of the microbiology of tonsils in children with TH and have important implications for antibiotic strategies.

Comparison of Sinus Deposition from an Aqueous Nasal Spray and Pressurised MDI in a Post-Endoscopic Sinus Surgery Nasal Replica.

BACKGROUND: Optimising intranasal distribution and retention of topical therapy is essential for effectively managing patients with chronic rhinosinusitis, including those that have had functional endoscopic sinus surgery (FESS). This study presents a new technique for quantifying in vitro experiments of fluticasone propionate deposition within the sinuses of a 3D-printed model from a post-FESS patient. METHODS: Circular filter papers were placed on the sinus surfaces of the model. Deposition of fluticasone on the filter paper was quantified using high-performance liquid chromatography (HPLC) assay-based techniques. The deposition patterns of two nasal drug delivery devices, an aqueous nasal spray (Flixonase) and metered dose inhaler (Flixotide), were compared. The effects of airflow (0 L/min vs. 12 L/min) and administration angle (30° vs. and 45°) were evaluated. RESULTS: Inhaled airflow made little difference to sinus deposition for either device. A 45° administration angle improved frontal sinus deposition with the nasal spray and both ethmoidal and sphenoidal deposition with the inhaler. The inhaler provided significantly better deposition within the ethmoid sinuses (8.5x) and within the maxillary sinuses (3.9x) compared with the nasal spray under the same conditions. CONCLUSION: In the post-FESS model analysed, the inhaler produced better sinus deposition overall compared with the nasal spray. The techniques described can be used and adapted for in vitro performance testing of different drug formulations and intranasal devices under different experimental conditions. They can also help validate computational fluid dynamics modelling and in vivo studies.

Sinonasal and gastrointestinal bacterial composition and abundance are stable after 1 week of once-daily oral antibiotic treatment for chronic rhinosinusitis.

BACKGROUND: Despite the widespread prescription of antibiotics for the treatment of chronic rhinosinusitis (CRS), their efficacy remains uncertain. Limited penetration of systemic antibiotics into the sinonasal mucosa has been reported previously by this group. This study aimed to investigate the short-term effects of antibiotics on the sinus and gut microbiota as well as any relationships these had with drug distribution. METHODS: Thirty subjects undergoing functional endoscopic sinus surgery for CRS were randomized to one of three groups: (1) doxycycline (100 mg daily for 7 days); (2) roxithromycin (300 mg daily for 7 days); and (3) control (no antibiotics given). Sinonasal and stool samples collected before and after treatment were analyzed using 16S ribosomal RNA (rRNA) gene-targeted amplicon sequencing and Droplet Digital polymerase chain reaction (PCR) for bacterial community composition and the quantification of bacterial DNA, respectively. RESULTS: There were no significant major bacterial community shifts or changes to bacterial diversity and load following the treatment period in all patient groups. Non-significant trend reductions were observed in gut microbial diversity with antibiotics. For the roxithromycin group, sinonasal bacterial diversity was negatively correlated with serum drug levels and reduced overall compared to controls (p < 0.05). The relative abundance of Staphylococcus ASV129 in sinonasal samples reduced with increasing mucus doxycycline levels (p = 0.01). CONCLUSION: Antibiotic prescription for CRS should be further investigated because of preliminary evidence of poor sinonasal drug penetration, unproven efficacy, and the potential impact of dysbiosis in the sinuses and off-target sites. Further studies should consider distinguishing the presence of DNA from viable and nonviable bacteria.

Nasal air conditioning following total inferior turbinectomy compared to inferior turbinoplasty - A computational fluid dynamics study.

BACKGROUND: The aim of this study was to use computational fluid dynamics (CFD) to investigate the effects on nasal heat exchange and humidification of two different surgical techniques for reducing the inferior turbinate under different environmental conditions. METHODS: Virtual surgery using two techniques of turbinate reduction was performed in eight nasal airway obstruction patients. Bilateral nasal airway models for each patient were compared: 1) Pre-operative 2) Post inferior turbinoplasty 3) Post total inferior turbinate resection (ITR). Two representative healthy models were included. Three different environmental conditions were investigated 1) ambient air 2) cold, dry air 3) hot, humid air. CFD modelling of airflow and conditioning was performed under steady-state, laminar, inspiratory conditions. FINDINGS: Nasal conditioning is significantly altered following inferior turbinate reduction surgery, particularly with ITR under cold, dry inspired air (CDA). The degree of impairment is minor under the simulated range of environmental conditions (temperature = 12-40 °C; relative humidity = 13-80%). Streams of significantly colder air are found in the nasopharynx and more prevalent under CDA in ITR. These are related to high velocity flow streams, which remain cool in their centre throughout the widened inferior nasal cavity. INTERPRETATION: Reduced air-mucosal heat exchange and moisture carrying capacity occurs under cooler temperatures in patients following inferior turbinate surgery. The clinical impact in extremely cold and dry conditions in groups with poor baseline respiratory function, respiratory illness, or endurance athletes is of special interest.

Effect of tonsillectomy on antibiotic prescribing in children.

INTRODUCTION: Tonsillectomy is the second most common surgical procedure performed in pediatric otolaryngology. Multiple courses of antibiotics are usually prescribed prior to surgical intervention. Surgery is indicated when patients reach a certain number of infective episodes, or their obstructive symptoms warrant intervention. Little is known about the role of tonsillectomy on long term postoperative antibiotic use. Recently, our group published a retrospective case series that described the clinical characteristics and outcomes of children under the age of 16 years who underwent tonsillectomy. This study is a follow-up on this previous case series and its purpose is to determine whether tonsillectomy in this group of children led to a reduction in the number of antibiotics prescribed in the year following surgery. METHODS: Data were collected from the clinical records departments of two district health boards in Auckland, New Zealand. Hospital morbidity records were reviewed for all children younger than 16 years old, who underwent a tonsillectomy between December 2015 and December 2017 in the Auckland region. All antibiotics prescribed following surgery were obtained from New Zealand's national community prescribing database. RESULTS: A total of 1538 children underwent tonsillectomy during the study period. Following surgery, antibiotics were prescribed to 828 (54%) patients at the time of discharge, with an average of 1.2 ± 0.1 courses in the year following surgery. This was significantly reduced compared to preoperative antibiotic intake (3.4 ± 0.1 courses) in the year preceding surgery (p < 0.001). Readmission within 30 days of discharge was not associated with increased antibiotic usage postoperatively. In the two weeks following surgery, 25% of patients were prescribed a course of antibiotics for a presumed postoperative infection. CONCLUSIONS: These findings support the benefit of tonsillectomy in reducing antibiotic consumption in the year following surgery. Furthermore, it has highlighted areas of practice, such as perioperative antibiotic prescription, which can be improved to further reduce the prescription of antibiotics for children with tonsillar hyperplasia.

Oral antibiotics used in the treatment of chronic rhinosinusitis have limited penetration into the sinonasal mucosa: a randomized trial.

Despite the widespread prescription of antibiotics for patients with chronic rhinosinusitis (CRS), the extent to which drug distribution to the sinonasal mucosa occurs remains largely undefined. Twenty subjects undergoing functional endoscopic sinus surgery (FESS) for CRS were randomized to one of two groups: 1) doxycycline (100 mg daily for seven days) 2) roxithromycin (300 mg daily for seven days). Drug levels were measured using liquid chromatography-tandem mass spectrometry in sinonasal mucus, sinonasal tissues and serum at steady state. Doxycycline concentrations measured in the mucus were significantly lower compared to that in the serum (mean mucus/serum ratio = 0.16, p < 0.001) and the tissue (mean mucus/tissue ratio = 0.18, p < 0.0001). Roxithromycin concentrations in the mucus were also significantly lower compared to that in the serum (mean mucus/serum ratio = 0.37, p = 0.002) and the tissue (mean mucus/tissue ratio = 0.60, p < 0.001). Although the efficacy of doxycycline and roxithromycin in sinonasal mucus in vivo cannot be predicted solely from reported minimum inhibitory concentrations, given the added complexity of bacterial biofilm antimicrobial tolerance, these results suggest that low mucosal penetration of antibiotics may be one of the factors contributing to the limited efficacy of these agents in the treatment of CRS.

Magnetic resonance imaging evaluation of the distribution of spray and irrigation devices within the sinonasal cavities.

BACKGROUND: Optimizing intranasal distribution and retention of nasal sprays is essential in the management of patients with chronic rhinosinusitis (CRS), including those that have had functional endoscopic sinus surgery (FESS). Despite multiple existing distribution studies, there remains a need for a technique that allows regionalization of particle deposition within a patient's unique 3-dimensional (3D) geometry without exposing the patient to radiation. METHODS: Seven participants delivered normal saline containing a gadolinium-based contrast agent (GBCA) by either saline irrigation or nasal sprays on 1 side of the nasal cavity. The saline irrigation group included 2 participants (both healthy) while the nasal spray group included 5 participants (2 healthy, 2 post-FESS patients, 1 CRS patient without any sinus surgery). The distribution of new signal enhancement was assessed on each participant using magnetic resonance imaging (MRI). Serial scans were performed over an interval of 4 minutes in the nasal spray group to assess changes in intranasal distribution over time. RESULTS: Signal enhancement was widespread within the nasal cavities and maxillary sinuses of participants (both healthy) that underwent sinus irrigation. For the nasal spray participants, the hotspots for signal enhancement were similar regardless of disease status or previous history of surgery. These included the internal nasal valve, anterior septum, inferior surface of the inferior turbinate, nasal floor, and nasopharynx. No signal enhancement was detected with nasal sprays in either unoperated or operated paranasal sinuses. CONCLUSION: A technique has been developed using MRI evaluation of radioopaque contrast to characterize the temporospatial distribution of topical drug delivery within the sinonasal cavities.

Bacterial microcolonies exist within the sphenoid bone in chronic rhinosinusitis and healthy controls.

BACKGROUND: Some patients with chronic rhinosinusitis (CRS) exhibit thickening of the sinus bones that has been termed osteitis. The histopathology and microbiology of these changes have not been fully described. The aim of this study was to look for the presence of bacteria and immune cells within samples of bone from patients with and without CRS and correlate these findings to radiological findings. METHODS: Bone on the anterior face of the sphenoid was examined radiologically and histologically in 8 patients with CRS with nasal polyposis, 8 patients with CRS without polyposis, and 6 control patients with pituitary adenomas and normal sinuses. Bone thickness and density were measured by computed tomography (CT) scanning. Bone samples were collected intraoperatively and 20 tissue sections were analyzed for each patient. Bacteria were identified by Giemsa and Gram stains. Immune cells were identified by conventional histology and immunohistochemistry. RESULTS: Small colonies of bacteria were identified within the bone in 3 of 16 CRS patients and 2 of 6 control subjects (p = 0.6). Isolated immune cells were identified within the bone in 3 of 16 CRS patients and 2 of 6 control subjects (p = 0.6) but both bacteria and immune cells occurred together in only 1 case. The presence of bacteria or immune cells within bone samples did not correlate with either bone thickness or bone density. CONCLUSION: This study describes the presence of bacteria and immune cells within a minority of CRS patients and normal controls. The bacterial microcolonies identified do not appear to be the cause of the bone changes seen in many CRS patients.

Is chronic rhinosinusitis caused by persistent respiratory virus infection?

BACKGROUND: Many chronic rhinosinusitis (CRS) patients recall an upper respiratory tract infection as the inciting event of their chronic illness. Viral infections have been shown to cause obstruction of the osteomeatal complex, which is likely to be a critical step in the development of CRS. There is clear overlap between the pathogenesis of CRS and asthma. Infections with respiratory viruses in childhood increase the risk of subsequently developing asthma. Viral infections in established asthmatics are associated with acute exacerbations. We sought to determine whether respiratory viruses could be detected within the sinonasal mucosa of CRS patients using polymerase chain reaction (PCR) techniques. METHODS: Sinus mucosa was sampled from 13 patients with CRS and 2 patients with normal sinuses. PCR was used to look for common respiratory viruses (parainfluenza 1, 2, and 3; respiratory syncytial virus [RSV]; human metapneumovirus [hMPV]; adenovirus [ADV]; rhinovirus; coronavirus; bocavirus [BoV]; cytomegalovirus [CMV]; and influenza A and B). RESULTS: No respiratory viruses were detected in any of the samples. CONCLUSION: Persistence of respiratory viruses within the sinonasal mucosa is unlikely to be a cause of ongoing inflammation in CRS. The possibility remains that a transient viral infection provides the initial inflammatory stimulus.

Are biofilms associated with an inflammatory response in chronic rhinosinusitis?

BACKGROUND: Bacterial biofilms have been identified on the sinonasal mucosa of patients with chronic rhinosinusitis (CRS) but also on control samples. Their role in the disease pathogenesis is unproven. The objective of this study was to further evaluate the role of biofilms in CRS by assessing whether they are associated with an inflammatory response. METHODS: Mucosal samples were collected from 18 patients with CRS and 7 normal subjects. Bacteria on the mucosal surface were identified by Gram stain. Immune cells were identified by Giemsa stain and immunohistochemistry (IHC). The number of local immune cells was recorded beneath areas of the mucosal surface both colonized with and free from bacteria. RESULTS: In CRS patients, biofilms that were directly opposed to a disrupted epithelial layer were associated with more T lymphocytes (p = 0.01), and more macrophages (p = 0.003) than areas of mucosa without bacteria present. Biofilms associated with but not directly opposed to the epithelium were not associated with raised numbers of immune cells. CONCLUSION: Not all surface bacterial colonies are associated with a particular inflammatory response in CRS. Biofilms adherent to a disrupted epithelial layer are associated with higher numbers of immune cells and therefore appear to have a role in the pathogenesis of CRS.

The prevalence of atopic symptoms in children with otitis media with effusion.

OBJECTIVE: To determine the prevalence of allergic symptoms in children with otitis media with effusion (OME). STUDY DESIGN: A validated questionnaire from the International Study of Asthma and Allergies in Childhood was used to determine the prevalence of allergic symptoms in children. The questionnaire was completed by the parents of children with OME undergoing ventilation tube insertion, and the results were compared with a large reference group of school children of the same age. SUBJECTS AND METHODS: Children aged 6 or 7 years old with OME confirmed intraoperatively during ventilation tube insertion between 2001 and 2005 (n=89). The prevalence of allergic symptoms and nasal symptoms in children with OME was compared with an age-matched reference group. RESULTS: There was no difference in the prevalence of allergic symptoms suggesting rhinoconjunctivitis, asthma, or eczema between the OME and reference group. The prevalence of nasal symptoms, however, was greater in the children with OME than in the reference group 38.2 percent versus 23.5 percent (odds ratio=2.01; 95% confidence interval, 1.30-3.10; P<0.001). CONCLUSION: The prevalence of allergic symptoms was similar in 6- to 7-year-old children with OME and the reference group, suggesting a limited effect of allergy in the pathogenesis of OME in this age group. Nasal symptoms were more common in the OME group, which may reflect a higher prevalence of adenoidal hyperplasia.