Chronic rhinosinusitis and antibiotics: the good, the bad, and the ugly

Discordance of chronic rhinosinusitis disease control between EPOS guidelines and patient perspectives identifies utility of patient-rated control assessment

Background: The objective of this study was to determine concordance of patient-reported chronic rhinosinusitis (CRS) disease control with CRS disease control assessed according to European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) criteria. Methods: In 421 participants, CRS disease control was determined using EPOS criteria which include the burden of 5 symptoms measured on a binary scale, use of rescue medications in the prior 6 months and presence of diseased mucosa on nasal endoscopy. Symptom severity was also assessed using a visual analogue scale (VAS). Participants rated their CRS disease control as “controlled”, “partly controlled” or “uncontrolled”. Results: Patient-reported and EPOS-based CRS disease control ratings agreed for 49.6% of participants. Amongst cases of disagreement, EPOS guidelines assessed worse CRS disease control relative to 92.9% of patients. Facial pain/pressure and impaired sense of smell distinctly associated with patient agreement with EPOS guidelines on having “uncontrolled” CRS. Higher VAS symptom scores were associated with worse patient-reported CRS disease control (i.e., agreeing with EPOS guidelines). Removal of the nasal endoscopy criterion improved agreement between patients’ and EPOS control assessments, and replacement of this criterion with patient-reported control further aligned EPOS guidelines with patient perspectives. Conclusions: EPOS guidelines regularly assess worse CRS control than assessed by patients. The lack of more gradated symptom severity criteria and inclusion of nasal endoscopy may contribute to discordance of EPOS guidelines with patient-reported CRS control. Replacement of nasal endoscopy findings with a measure of patient-reported CRS disease control better aligns EPOS CRS disease control guidelines with patients’ perspectives.

Associations Between Chronic Rhinosinusitis and Cancers: A Nationwide Population-Based Cohort Study

OBJECTIVE

Chronic rhinosinusitis (CRS) is one of the most common chronic inflammatory diseases. The effect of chronic inflammation caused by CRS on the occurrence of various cancers has not been thoroughly evaluated. This study aimed to investigate the increased incidences of 10 types of cancers among CRS patients with/without nasal polyps (NP) using a national population-based database from the Korean Health Insurance Review and Assessment Service.

STUDY DESIGN

A case-control cohort study.

METHODS

We compared the prevalence of various comorbidities between CRS and control participants from a national cohort dataset of the Korean Health Insurance Review and Assessment Service.

METHODS

CRS participants (n = 6,919) and non-CRS (n = 27,676) participants were selected from among the 514,866 participants from 2002 to 2015. A stratified Cox proportional hazards model was utilized to assess the hazard ratio (HR) of CRS for 10 types of cancers.

RESULTS

A stratified Cox proportional hazard model demonstrated that the adjusted HR for hematologic malignancy was significantly higher in the CRS patients than in the controls regardless of the presence of NP (2.90 for total CRS; 2.15 for CRS with NP; 4.48 for CRS without NP). The HR for thyroid cancer was significantly higher in the CRS patients without NP but not in those with NP (1.50 for total CRS; 1.78 for CRS without NP).

CONCLUSION

This study showed that CRS participants had a significantly higher prevalence of hematologic malignancy and thyroid cancer.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Novel strategies for inhibition of bacterial biofilm in chronic rhinosinusitis

An important role has been recently reported for bacterial biofilm in the pathophysiology of chronic diseases, such as chronic rhinosinusitis (CRS). CRS, affecting sinonasal mucosa, is a persistent inflammatory condition with a high prevalence around the world. Although the exact pathological mechanism of this disease has not been elicited yet, biofilm formation is known to lead to a more significant symptom burden and major objective clinical indicators. The high prevalence of multidrug-resistant bacteria has severely restricted the application of antibiotics in recent years. Furthermore, systemic antibiotic therapy, on top of its insufficient concentration to eradicate bacteria in the sinonasal biofilm, often causes toxicity, antibiotic resistance, and an effect on the natural microbiota, in patients. Thus, coming up with alternative therapeutic options instead of systemic antibiotic therapy is emphasized in the treatment of bacterial biofilm in CRS patients. The use of topical antibiotic therapy and antibiotic eluting sinus stents that induce higher antibiotic concentration, and decrease side effects could be helpful. Besides, recent research recognized that various natural products, nitric oxide, and bacteriophage therapy, in addition to the hindered biofilm formation, could degrade the established bacterial biofilm. However, despite these improvements, new antibacterial agents and CRS biofilm interactions are complicated and need extensive research. Finally, most studies were performed in vitro, and more preclinical animal models and human studies are required to confirm the collected data. The present review is specifically discussing potential therapeutic strategies for the treatment of bacterial biofilm in CRS patients.

Radiographic disease severity in chronic rhinosinusitis patients and health care utilization

OBJECTIVES

Chronic rhinosinusitis (CRS) affects approximately 12% of the population and leads to increased health care utilization and indirect costs exceeding $20 billion annually in the United States. The Lund-Mackay score (LMS) measures radiographic disease severity for CRS but poorly correlates with symptom scores. The association between LMS and health care utilization in CRS patients has not yet been investigated. The study aimed to assess the association between health care utilization and CRS radiographic severity using LMS.

METHODS

CRS patients enrolled in a clinical registry were evaluated. Nasal endoscopy findings and LMS were recorded for patients with sinus CT imaging. Patient symptom scores, demographic characteristics, and health care utilization measures were collected. The relationship between these factors and LMS was examined.

RESULTS

A total of 556 patients met inclusion criteria. Mean age was 45.3 years, 53.4% were male, and 41.7% had nasal polyps. There was no difference in sex, smoking history, 22-item Sino-nasal Outcome Test scores, or past medical history factors between patients with high (≥8, n = 410) and low (<8, n = 146) LMS. Among high LMS patients, 73.7% underwent endoscopic sinus surgery (ESS) compared to 55.5% with low LMS (P < .01), and a greater percentage of patients had nasal polyps (49.3% vs 20.5%, P < .01). On multivariable logistic regression, high LMS patients used fewer antibiotic courses (OR: 0.68 [0.51-0.91]), but were more likely to be managed with ESS (OR: 2.28 [1.41-3.73]), and have nasal polyps (OR: 2.11 [1.16-3.93]) compared to low LMS patients. There was no significant difference in the number of steroid courses, over the counter pill use, provider visits, work/school days missed, or symptom duration between the two LMS groups.

CONCLUSION

CRS patients with severe radiographic disease are more likely to have nasal polyps, undergo ESS, and take fewer antibiotic courses. However, there is no association between radiographic disease severity and other measures of health care utilization.

LEVEL OF EVIDENCE

2b, individual retrospective cohort study.

Complications Associated with PROPEL Mometasone Furoate Bioabsorbable Drug-eluting Sinus Stents From 2012 to 2020

BACKGROUND

Till date, there have been no studies that have analyzed a database to examine postmarket adverse events associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents.

OBJECTIVE

To determine the postmarket complications associated with PROPEL mometasone furoate bioabsorbable drug-eluting sinus stents.

METHODS

The US Food and Drug Administration's Manufacturer and User Facility Device Experience database was searched for adverse events associated with PROPEL bioabsorbable drug-eluting sinus stents between January 1, 2012 and December 31, 2020. Data were extracted and analyzed from medical device reports (MDRs) that involved sinus stents.

RESULTS

After 47 MDRs were identified, 25 reports involving PROPEL bioabsorbable drug-eluting sinus stents were reviewed, from which 40 adverse events were recorded. Of these, there were 32 adverse events to patients and 8 device malfunctions. The most common adverse events to patients included infection (21.8%), oropharyngeal obstruction (15.6%), and headache/pain (12.5%). The most common device malfunction reported was migration and expulsion of the stent (87.5%).

CONCLUSIONS

PROPEL sinus stents have been shown to be effective in preventing sinus outflow obstruction after functional endoscopic sinus surgery. Both adverse events to patients and device malfunctions are reported infrequently. A more comprehensive understanding of rare postmarket complications seen with PROPEL sinus stents may further aid informed decision-making regarding their usage.

Antibiofilm peptides: overcoming biofilm-related treatment failure

Health leaders and scientists worldwide consider antibiotic resistance among the world's most dangerous pathogens as one of the biggest threats to global health. Antibiotic resistance has largely been attributed to genetic changes, but the role and recalcitrance of biofilms, largely due to growth state dependent adaptive resistance, is becoming increasingly appreciated. Biofilms are mono- and multi-species microbial communities embedded in an extracellular, protective matrix. In this growth state, bacteria are transcriptionally primed to survive extracellular stresses. Adaptations, affecting metabolism, regulation, surface charge, immune recognition and clearance, allow bacteria to thrive in the human body and withstand antibiotics and the host immune system. Biofilms resist clearance by multiple antibiotics and have a major role in chronic infections, causing more than 65% of all infections. No specific antibiofilm agents have been developed. Thus, there is a pressing need for alternatives to traditional antibiotics that directly inhibit and/or eradicate biofilms. Host defence peptides (HDPs) are small cationic peptides that are part of the innate immune system to both directly kill microbes but also function to modulate the immune response. Specific HDPs and their derivatives demonstrate broad-spectrum activity against biofilms. In vivo biofilm assays show efficacy in abscess, respiratory, in-dwelling device, contact lens and skin infection models. Further progress has been made through the study of ex vivo organoid and air-liquid interface models to better understand human infections and treatment while relieving the burden and complex nature of animal models. These avenues pave the way for a better understanding and treatment of the underlying cause of chronic infections that challenge the healthcare system.

Antibiotic Treatment for Chronic Rhinosinusitis: Prescription Patterns and Associations With Patient Outcome and the Sinus Microbiota

Background

Chronic rhinosinusitis (CRS) is a common and debilitating inflammatory condition of the sinuses, afflicting 5% of the general population. Although antibiotics are frequently prescribed for the medical management of CRS, there is surprisingly little evidence to support their efficacy. In this study, we aimed to establish associations between medication usage, the sinus microbiota and patients’ clinical outcomes.

Methods

Antibiotic prescription patterns for the year before sample collection of 156 CRS patients, 45 disease control patients (mostly requiring septoplasty and inferior turbinate reduction) and 35 healthy control subjects were examined and analyzed together with previously published bacterial 16S rRNA gene amplicon data from our group.

Results

The highest antibiotic usage was observed among the two CRS patient categories. Despite heavy antibiotic usage, CRS patients’ clinical outcomes as indicated by patient questionnaires and radiologic scores were similar to those patients that did not receive any antibiotics. The sinus microbiota was dominated by members of the bacterial genera Corynebacterium and Staphylococcus in all three cohorts. Bacterial community dispersion as measured by principal coordinate analysis was significantly higher in CRS patients compared to healthy control subjects, but not disease control patients. Pairwise comparisons within cohorts revealed differences in the relative 16S rRNA gene sequence abundances of the genera Staphylococcus and Lawsonella between antibiotic users and non-users. However, overall antibiotic effects were minimal and unpredictable.

Conclusion

The unpredictable effects of antibiotic treatment on the sinus microbiota found in this study, together with the lack of differences in patients’ symptom scores between cohorts, do not support preoperative antibiotic treatment for CRS patients.

The influence of nasal bacterial microbiome diversity on the pathogenesis and prognosis of chronic rhinosinusitis patients with polyps

PURPOSE

The role of the microbiome in the paranasal sinuses and its contribution to sinus mucosal health and disease remains poorly understood. Consequently, we examined the nasal microbiome of chronic rhinosinusitis patients with polyps (CRSwNP), chronic sinusitis without nasal polyps (CRSsNP) and a control population, associated with IL-5 of nasal polyp tissues and postoperative follow-up of CRSwNP patients, in search of nasal microbial community characteristics related to pathogenesis and prognosis of CRSwNP, providing a new perspective for further understanding of the disease.

METHODS

The middle meatus secretions of 77 CRSwNP, 36 CRSsNP and 34 non-CRS subjects were collected. The bacterial microbiome composition was detected using high-throughput sequencing technology based on 16S rRNA, and the differences in the nasal microbial diversity among the three groups were compared. At the same time, nasal polyp tissues were collected to detect the expression of IL-5 and analyse its relationship with the structural characteristics of nasal microbial colonies. Postoperative follow-up of patients with CRSwNP was conducted for 1 year to record the recurrence of nasal polyps and analyse the correlation between the recurrence of nasal polyps and IL-5 as well as the characteristics of nasal microbial diversity.

RESULTS

The results showed that the average Sobs index (579.31) of the non-CRS group was significantly higher than that of the CRSwNP group (387.31, P = 0.03). PCoA analysis showed that the microbial distribution in the three groups was mostly similar, with only a few unique to each group. At the phylum level, Actinobacteria and Chlamydia in the non-CRS group were significantly higher than those in the CRSwNP and CRSsNP groups. At the genus level, Corynebacterium and Dolosigranulum in the non-CRS group were significantly higher than those in the CRSwNP and CRSsNP groups. Twenty-five CRSwNP patients had nasal polyps that were IL-5 positive, accounting for 32.47%, and the relative abundance of Enterobacter was 6.37% ± 5.92%, which was significantly higher than 0.58% ± 0.11% in the IL-5 negative group. No significant difference was found after correction (p = 0.026, FDR p > 0.05). One year after surgery, 77 patients with CRSwNP who underwent surgery were successfully followed up, and 12 patients with CRSwNP relapsed, with a recurrence rate of 15.6%. Total nasal symptom scores (TNSS) were significantly higher in the recurrent group than in the nonrecurrent group (P = 0.000). No differences in microbial diversity were found between the CRSwNP populations in the recurrent group and the nonrecurrent group at both the phylum and genus levels. For the nonrecurrent CRSwNP group, the relative abundance of Actinobacteria (PDR P = 0.012) and Corynebacterium (PDR P = 0.003) was higher than that before surgery, and the relative abundance of Bacteroidetes (PDR P = 0.040) was lower than that before surgery. However, for the recurrence CRSwNP group, there was no significant difference in the nasal microbiome between postoperation and preoperation.

CONCLUSION

In conclusion, microbial dysbiosis in the nasal cavity is associated with the pathogenesis of CRSwNP. In Southwest China, the inflammatory pattern of nasal polyps is not dominated by eosinophilic infiltration of Th2-type inflammation. The recurrence of nasal polyps after ESS may be potentially related to the decrease in protective bacteria and the increase in pathogenic bacteria, and the improvement of postoperative bacterial disorder is correlated with the nonrecurrence of CRSwNP.

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.

Antibiotic eluting sinus stents

OBJECTIVES

Chronic rhinosinusitis (CRS) is a multifactorial disease affecting up to 16% of the United States population and disproportionately affecting the cystic fibrosis (CF) patient population. Despite treating the underlying infection, the use of systemic antibiotics has shown little efficacy in alleviation of symptom burden. This review seeks to discuss recent research on novel antibiotic eluting stent therapy in vitro and within animal models as well as the factors that contribute to its efficacy.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of all published literature related to antibiotic eluting sinus stents was conducted to integrate and summarize this innovative approach to chronic sinus infections.

RESULTS

Placement of the ciprofloxacin sinus stent (CSS) and ciprofloxacin-ivacaftor sinus stent (CISS) exhibited improvement in endoscopic and radiographic findings in rabbit CRS models. While the CSS showed an overall trend toward improvement in microscopic findings and a reduction in biofilm mass, there remained a significant quantity of planktonic bacteria due to antibiotic depletion from an initial burst release in the first 48 hours of stent placement. The CISS and ciprofloxacin-azithromycin sinus stents (CASSs) exhibited controlled antibiotic release over the study period leading to greatly reduced planktonic bacterial load and biofilm mass. In vitro studies indicate that CASS may be just as efficacious at reducing biofilm mass.

CONCLUSION

Antibiotic eluting sinus stents show significant promise as a novel therapeutic strategy for CRS. The CISS may have particular promise for the CF patient population by addressing both the infectious and genetic components of disease. Animal studies demonstrate significant promise for translation into human studies. Human clinical trials are warranted to determine the efficacy of antibiotic sinus stents in human patients.

LEVEL OF EVIDENCE

NA.

In-vitro evaluation of a ciprofloxacin and azithromycin sinus stent for Pseudomonas aeruginosa biofilms

BACKGROUND

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease characterized by persistent inflammation and bacterial infection. Ciprofloxacin and azithromycin are commonly prescribed antibiotics for CRS, but the ability to provide targeted release in the sinuses could mitigate side effects and improve drug concentrations at the infected site. This study was aimed to evaluate the efficacy of the novel ciprofloxacin-azithromycin sinus stent (CASS) in vitro.

METHODS

The CASS was created by coating ciprofloxacin (hydrophilic, inner layer) and azithromycin (hydrophobic, outer layer) onto a biodegradable poly-l-lactic acid (PLLA) stent. In-vitro evaluation included: (1) assessment of drug-coating stability within the stent using scanning electron microscopy (SEM); (2) determination of ciprofloxacin and azithromycin release kinetics; and (3) assessment of anti-biofilm activities against Pseudomonas aeruginosa.

RESULTS

The ciprofloxacin nanoparticle suspension in the inner layer was confirmed by zeta potential. Both ciprofloxacin (60 µg) and azithromycin (3 mg) were uniformly coated on the surface of the PLLA stents. The CASS showed ciprofloxacin/azithromycin sustained release patterns, with 80.55 ± 11.61% of ciprofloxacin and 93.85 ± 6.9% of azithromycin released by 28 days. The CASS also significantly reduced P aeruginosa biofilm mass compared with bare stents and controls (relative optical density units at 590-nm optical density: CASS, 0.037 ± 0.006; bare stent, 0.911 ± 0.015; control, 1.000 ± 0.000; p < 0.001; n = 3).

CONCLUSION

The CASS maintains a uniform coating and sustained delivery of ciprofloxacin and azithromycin, providing anti-biofilm activities against P aeruginosa. Further studies evaluating the efficacy of CASS in a preclinical model are planned.

Measuring antibiotic levels and their relationship with the microbiome in chronic rhinosinusitis

Background

The evidence supporting the efficacy of antibiotic therapy in the treatment of chronic rhinosinusitis is not compelling. A limited number of studies show that the changes in the nasal microbiome in patients following drug therapy are unpredictable and variable. The evidence for the impact of oral antibiotics on the gut microbiota is stronger, possibly as a result of differences in drug distribution to various sites around the body. There are few studies on sinus mucosal and mucus levels of oral antibiotics used in the treatment of chronic rhinosinusitis. The distribution dependent effects of antibiotics on the sinonasal microbiome is unclear.

Conclusion

This review highlights that relative drug concentrations and their efficacy on microbiota at different sites is an important subject for future studies investigating chronic rhinosinusitis.

Exacerbations of Chronic Rhinosinusitis-Microbiology and Perspectives of Phage Therapy

The chronically inflamed mucosa in patients with chronic rhinosinusitis (CRS) can additionally be infected by bacteria, which results in an acute exacerbation of the disease (AECRS). Currently, AECRS is universally treated with antibiotics following the guidelines for acute bacterial rhinosinusitis (ABRS), as our understanding of its microbiology is insufficient to establish specific treatment recommendations. Unfortunately, antibiotics frequently fail to control the symptoms of AECRS due to biofilm formation, disruption of the natural microbiota, and arising antibiotic resistance. These issues can potentially be addressed by phage therapy. In this study, the endoscopically-guided cultures were postoperatively obtained from 50 patients in order to explore the microbiology of AECRS, evaluate options for antibiotic treatment, and, most importantly, assess a possibility of efficient phage therapy. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently isolated bacteria, followed by Haemophilus influenzae, Pseudomonas aeruginosa, and Enterobacteriaceae. Alarmingly, mechanisms of antibiotic resistance were detected in the isolates from 46% of the patients. Bacteria not sensitive to amoxicillin were carried by 28% of the patients. The lowest rates of resistance were noted for fluoroquinolones and aminoglycosides. Fortunately, 60% of the patients carried bacterial strains that were sensitive to bacteriophages from the Biophage Pharma collection and 81% of the antibiotic-resistant strains turned out to be sensitive to bacteriophages. The results showed that microbiology of AECRS is distinct from ABRS and amoxicillin should not be the antibiotic of first choice. Currently available bacteriophages could be used instead of antibiotics or as an adjunct to antibiotics in the majority of patients with AECRS.

Taste Receptors in Upper Airway Innate Immunity

Taste receptors, first identified on the tongue, are best known for their role in guiding our dietary preferences. The expression of taste receptors for umami, sweet, and bitter have been demonstrated in tissues outside of the oral cavity, including in the airway, brain, gastrointestinal tract, and reproductive organs. The extra-oral taste receptor chemosensory pathways and the endogenous taste receptor ligands are generally unknown, but there is increasing data suggesting that taste receptors are involved in regulating some aspects of innate immunity, and may potentially control the composition of the nasal microbiome in healthy individuals or patients with upper respiratory diseases like chronic rhinosinusitis (CRS). For this reason, taste receptors may serve as potential therapeutic targets, providing alternatives to conventional antibiotics. This review focuses on the physiology of sweet (T1R) and bitter (T2R) taste receptors in the airway and their activation by secreted bacterial products. There is particular focus on T2R38 in sinonasal ciliated cells, as well as the sweet and bitter receptors found on specialized sinonasal solitary chemosensory cells. Additionally, this review explores the impact of genetic variations in these receptors on the differential susceptibility of patients to upper airway infections, such as CRS.

Antibodies against the DNABII protein integration host factor (IHF) inhibit sinus implant biofilms

OBJECTIVES

Chronic rhinosinusitis is a common, costly condition often treated with endoscopic sinus surgery and intraoperative placement of intranasal sinus implant materials. Whereas these materials aid in postoperative healing, they also support bacterial biofilm formation and thus contribute to negative outcomes. This study examined pretreatment of sinus implant materials with antibody against an essential bacterial biofilm structural component, the DNABII family of DNA-binding proteins, as a strategy to prevent biofilm formation.

METHODS

Sinus implant materials were equilibrated in immunoglobulin G (IgG)-enriched antiserum against the DNABII protein integration host factor (IHF), individually or in combination with amoxicillin-clavulanate prior to inoculation with nontypeable Haemophilus influenzae (NTHI), a predominant pathogen of chronic rhinosinusitis. After 16 hours, the bacterial burden was quantitated and compared to pretreatment with saline, IgG-enriched naive serum, or amoxicillin-clavulanate alone.

RESULTS

NTHI readily formed biofilms on all three materials in vitro. However, pretreatment of each material with IgG-enriched anti-IHF resulted in a significant decrease in bacterial burden compared to controls (P ≤ 0.05). Moreover, a significant and synergistic outcome was achieved with a cocktail of anti-IHF plus amoxicillin-clavulanate (P ≤ 0.05) with complete inhibition of NTHI biofilm formation on all three materials.

CONCLUSIONS

Biofilm formation was well supported in vitro on three sinus implant materials that vary in composition and resorption characteristics; however, pretreatment of each with DNABII protein targeted antibodies in combination with a previously ineffective antibiotic was highly effective to prevent the formation NTHI biofilms. These data demonstrate the potential for clinical utility of pretreatment of sinus implant and additional surgical materials with anti-DNABII antibodies.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:1364-1371, 2020.

The T cell activating properties and antitumour activity of Staphylococcal Enterotoxin-like Q

Staphylococcal enterotoxins (SEs), as typical superantigens, exhibit promising antitumour activity in the clinic, but their unavoidable side effects related to fever and emesis seriously limit their application for the treatment of malignant tumours. Fortunately, the identification of Staphylococcal enterotoxin-like toxins (SEls), which possess amino acid sequences similar to those of classical SEs but exhibit no or low emetic activity, has provided a set of potential immunomodulatory candidates for cancer therapy. The aim of this study was to examine the effect of SElQ on lymphocyte activation and to further demonstrate its antitumour activity both in vitro and in vivo. High-purity SElQ was successfully harvested, and in vitro results confirmed that SElQ can significantly activate mouse- and human-derived lymphocytes in a dose-dependent manner, particularly CD4⁺ and CD8⁺ T cells, which showed significant increases in both percentage and absolute number. Further examination revealed that in addition to the originally recognized TCR Vβ5 and 21, TCR Vβ14, 17 and 18 were activated in SElQ-induced human PBMCs. Moreover, the expression of IL-2 and IFN-γ was significantly upregulated in vitro and in vivo after SElQ treatment. Based on the findings that SElQ induces lymphocyte activation and cytokine release, we then confirmed its antitumour activity both in vitro and in vivo. The data showed that treatment with a low concentration of SElQ (30 µg/mouse) could inhibit the growth of tumours by approximately 30% and no significant toxicity was observed. Taken together, our results demonstrated that SElQ can significantly induce T cell activation and cytokine release and further elicit substantial antitumour activity and thus provide support for the potential application of SElQ in cancer immunotherapy.

The Efficacy of Yogic Breathing Exercise Bhramari Pranayama in Relieving Symptoms of Chronic Rhinosinusitis

INTRODUCTION

A multitude of modalities are available for the treatment of chronic rhinosinusitis, however, each has its side effects and compliance issues. Bhramari pranayama, which is a breathing exercise in the practice of yoga, offers an inexpensive and free from side effect modality in this regard.

OBJECTIVE

The objective of this study was to evaluate the efficacy of Bhramari pranayama in relieving the symptoms of chronic sinusitis.

METHODOLOGY

A total of 60 patients with chronic sinusitis were randomly divided into two groups, one received conventional treatment of chronic sinusitis and the other group was in addition taught to practice yogic breathing exercise Bhramari pranayama. The patients were advised to practice this breathing exercise twice a day and were followed up at 1, 4, and 12 weeks using the Sino-Nasal Outcome Test (SNOT-22 score).

RESULTS

The mean SNOT-22 score in the group following the Bhramari pranayama breathing exercise using the ANOVA test improved from 39.13 ± 9.10 to 24.79 ± 8.31 (P = 0.0002), this improvement was seen by the end of 4 weeks itself and continued until the 12th week of assessment.

CONCLUSION

Integrating regular practice of Bhramari pranayama along with the conventional management of chronic rhinosinusitis is more effective than conventional management alone.

Bacteriological analysis of isolated chronic sinusitis without polyps

INTRODUCTION

Chronic sinusitis (CRS) is phenotypically divided into inflammation with polyps (CRSwNP) or without polyps (CRSsNP).

AIM

To try to explain the reasons for isolated sinusitis by analysing medical history as well as anatomical and bacteriological data.

MATERIAL AND METHODS

In 2016, endoscopic surgery was performed in 103 patients with CRSsNP within 6 months. The authors evaluated 28 patients with lesions in one sinus.

RESULTS

The patients did not report any previous facial trauma, dental procedures, there were no odontogenic causes of the disease. They had not been treated with antibiotics within 30 days prior to admission to hospital. Ninety-seven bacterial strains were grown, of which 32 in patients with isolated nasal sinusitis. Statistical analysis has shown that there is a trend toward a statistically significant (p = 0.0868) relationship between the presence of Staphylococcus aureus and the type of inflammation.

CONCLUSIONS

There is an indication that the presence of Staphylococcus aureus is associated with isolated sinusitis, especially in women.

Chronic Rhinosinusitis in Children: Pathophysiology, Evaluation, and Medical Management

PURPOSE OF REVIEW

Pediatric chronic rhinosinusitis (CRS) is a common disorder that carries significant morbidity. The diagnosis requires sinus symptoms that persist despite standard medical therapy greater than 3 months. Viral infections, allergies, and anatomic differences in children lead to chronic obstruction of the osteomeatal complex.

RECENT FINDINGS

Chronic rhinosinusitis as a diagnosis is a conglomeration of multiple phenotypes and endotypes. As such, the diagnosis and management are complex. New survey studies provide some consensus on prevalence and management of this disease in children. In this review, we highlight the differential diagnosis of pediatric CRS, including non-eosinophilic/infectious variants, eosinophilic variants with and without nasal polyps, allergic fungal sinusitis, aspirin-exacerbated respiratory disease, primary immunodeficiency, and disorders of mucociliary clearance. Further, we detail treatment options that should be considered. Finally, we feature emerging potential treatment options of CRS, including anti-immunoglobulin E, interleukin-5, and interleukin-4 receptor alpha subunit.

Taste receptors in the upper airway

Taste receptors were named for their originally-identified expression on the tongue and role in the sensation of taste (gustation). They are now known to be involved in many chemosensory processes outside the tongue. Expression of the receptors for bitter, sweet, and umami was recently identified in many organs, including the brain, airway, gastrointestinal tract, and reproductive systems. We do not yet know the full roles of these receptors in all of these tissues, nor do we know all of the endogenous ligands that activate them. However, taste receptors are emerging as potentially important therapeutic targets. Moreover, they may mediate some off target effects of drugs, as many medications in common clinical use are known to be bitter. The focus of this review is on recent basic and clinical data describing the expression of bitter (T2R) and sweet (T1R) receptors in the airway and their activation by secreted bacterial compounds. These receptors play important roles in innate immune nitric oxide production and antimicrobial peptide secretion, and may be useful targets for stimulating immune responses in the upper respiratory tract via topical therapies. Moreover, genetic variation in these receptors may play a role in the differential susceptibility of patients to certain types of respiratory infections as well as to differential outcomes in patients with chronic rhinosinusitis (CRS). CRS is a syndrome of chronic upper respiratory infection and inflammation and has a significant detrimental impact on patient quality of life. CRS treatment accounts for approximately 20% of adult antibiotic prescriptions and is thus a large driver of the public health crisis of antibiotic resistance. Taste receptors represent a novel class of therapeutic target to potentially stimulate endogenous immune responses and treat CRS patients without conventional antibiotics.

[Management of Rhinosinusitis in Primary Care]

Acute rhinosinusitis is an important health problem. Even though its frequency is not well documented in our country?, the economic burden it bears is not insignificant as it notably alters the quality of life of affected patients. Its diagnosis is generally clinical in nature, with further studies reserved only for the differential diagnoses of complications or tumour-like processes. The most frequent causes are viral infections, although Streptococcus pneumoniae and Haemophilus influenzae are the most commonly isolated bacterial agents. Although complications are uncommon nowadays, they can be serious when they occur, and commonly include orbital infections, closely followed in frequency by intracranial and bone infections. Treatment should consist of symptomatic measures, like saline rinses and antibiotics in cases of bacterial origin.

l-Methionine anti-biofilm activity against Pseudomonas aeruginosa is enhanced by the cystic fibrosis transmembrane conductance regulator potentiator, ivacaftor

BACKGROUND

Biofilms may contribute to refractory chronic rhinosinusitis (CRS), as they lead to antibiotic resistance and failure of effective clinical treatment. l-Methionine is an amino acid with reported biofilm-inhibiting properties. Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator with mild antimicrobial activity via inhibition of bacterial DNA gyrase and topoisomerase IV. The objective of this study was to evaluate whether co-treatment with ivacaftor and l-methionine can reduce the formation of Pseudomonas aeruginosa biofilms.

METHODS

P aeruginosa (PAO-1 strain) biofilms were studied in the presence of l-methionine and/or ivacaftor. For static biofilm assays, PAO-1 was cultured in a 48-well plate for 72 hours with stepwise combinations of these agents. Relative biofilm inhibitions were measured according to optical density of crystal violet stain at 590 nm. Live/dead assays (BacTiter-Glo™ assay, Promega) were imaged with laser scanning confocal microscopy. An agar diffusion test was used to confirm antibacterial effects of the drugs.

RESULTS

l-Methionine (0.5 μM) significantly reduced PAO-1 biofilm mass (32.4 ± 18.0%; n = 4; p < 0.001) compared with controls. Low doses of ivacaftor alone (4, 8, and 12 μg/mL) had no effect on biofilm formation. When combined with ivacaftor (4 μg/mL), a synergistic anti-biofilm effect was noted at 0.05 μM and 0.5 μM of l-methionine (two-way analysis of variane, p = 0.0415) compared with corresponding concentrations of l-methionine alone.

CONCLUSION

Ivacaftor enhanced the anti-biofilm activity of l-methionine against the PAO-1 strain of P aeruginosa. Further studies evaluating the efficacy of ivacaftor/l-methionine combinations for P aeruginosa sinusitis are planned.

Preclinical therapeutic efficacy of the ciprofloxacin-eluting sinus stent for Pseudomonas aeruginosa sinusitis

BACKGROUND

The ciprofloxacin-coated sinus stent (CSS) has unique therapeutic potential to deliver antibiotics to the sinuses. The objective of this study is to evaluate the efficacy of the CSS stent in eliminating Pseudomonas aeruginosa infection in a rabbit model of sinusitis.

METHODS

A ciprofloxacin-eluting sinus stent was created by coating ciprofloxacin/Eudragit RS100 on biodegradable poly-D/L-lactic acid (2 mg). After analyzing in-vitro inhibition of P aeruginosa (PAO-1 strain) biofilm formation, a total of 8 stents (4 shams, 4 CSSs) were placed unilaterally in rabbit maxillary sinuses via dorsal sinusotomy after inducing infection for 1 week with PAO-1. Animals were assessed 2 weeks after stent insertion with nasal endoscopy, sinus culture, computed tomography (CT) scan, histopathology, and scanning electron microscopy (SEM).

RESULTS

PAO-1 biofilm formation was significantly reduced in vitro with exposure to the CSS (p < 0.0001). Insertion of the stent in PAO-1-infected rabbits for 2 weeks resulted in significant improvement in sinusitis according to endoscopy scoring (p < 0.0001) and CT scoring (p < 0.002). Histology and SEM revealed marked improvement in the structure of the mucosa and submucosa with no detection of biofilm structures in the CSS cohort.

CONCLUSION

Although this study had a small sample size, we identified robust therapeutic efficacy of the CSS by reducing bacterial load and biofilm formation of P aeruginosa in a preclinical model of sinusitis after placement for 2 weeks.

Plant flavones enhance antimicrobial activity of respiratory epithelial cell secretions against Pseudomonas aeruginosa

Flavones are a class of natural plant secondary metabolites that have anti-inflammatory and anti-bacterial effects. Some flavones also activate the T2R14 bitter taste receptor, which is expressed in motile cilia of the sinonasal epithelium and activates innate immune nitric oxide (NO) production. Flavones may thus be potential therapeutics for respiratory infections. Our objective was to examine the anti-microbial effects of flavones on the common sinonasal pathogens Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa, evaluating both planktonic and biofilm growth. Flavones had only very low-level antibacterial activity alone. They did not reduce biofilm formation, but did reduce production of the important P. aeruginosa inflammatory mediator and ciliotoxin pyocyanin. However, flavones exhibited synergy against P. aeruginosa in the presence of antibiotics or recombinant human lysozyme. They also enhanced the efficacy of antimicrobials secreted by cultured and primary human airway cells grown at air-liquid interface. This suggests that flavones may have anti-gram-negative potential as topical therapeutics when combined with antibiotics or in the context of innate antimicrobials secreted by the respiratory or other epithelia. This may have an additive effect when combined with T2R14-activated NO production. Additional studies are necessary to understand which flavone compounds or mixtures are the most efficacious.

Chronic Rhinosinusitis and the Evolving Understanding of Microbial Ecology in Chronic Inflammatory Mucosal Disease

Chronic rhinosinusitis (CRS) encompasses a heterogeneous group of debilitating chronic inflammatory sinonasal diseases. Despite considerable research, the etiology of CRS remains poorly understood, and debate on potential roles of microbial communities is unresolved. Modern culture-independent (molecular) techniques have vastly improved our understanding of the microbiology of the human body. Recent studies that better capture the full complexity of the microbial communities associated with CRS reintroduce the possible importance of the microbiota either as a direct driver of disease or as being potentially involved in its exacerbation. This review presents a comprehensive discussion of the current understanding of bacterial, fungal, and viral associations with CRS, with a specific focus on the transition to the new perspective offered in recent years by modern technology in microbiological research. Clinical implications of this new perspective, including the role of antimicrobials, are discussed in depth. While principally framed within the context of CRS, this discussion also provides an analogue for reframing our understanding of many similarly complex and poorly understood chronic inflammatory diseases for which roles of microbes have been suggested but specific mechanisms of disease remain unclear. Finally, further technological advancements on the horizon, and current pressing questions for CRS microbiological research, are considered.

Bacterial d-amino acids suppress sinonasal innate immunity through sweet taste receptors in solitary chemosensory cells

In the upper respiratory epithelium, bitter and sweet taste receptors present in solitary chemosensory cells influence antimicrobial innate immune defense responses. Whereas activation of bitter taste receptors (T2Rs) stimulates surrounding epithelial cells to release antimicrobial peptides, activation of the sweet taste receptor (T1R) in the same cells inhibits this response. This mechanism is thought to control the magnitude of antimicrobial peptide release based on the sugar content of airway surface liquid. We hypothesized that d-amino acids, which are produced by various bacteria and activate T1R in taste receptor cells in the mouth, may also activate T1R in the airway. We showed that both the T1R2 and T1R3 subunits of the sweet taste receptor (T1R2/3) were present in the same chemosensory cells of primary human sinonasal epithelial cultures. Respiratory isolates of Staphylococcus species, but not Pseudomonas aeruginosa, produced at least two d-amino acids that activate the sweet taste receptor. In addition to inhibiting P. aeruginosa biofilm formation, d-amino acids derived from Staphylococcus inhibited T2R-mediated signaling and defensin secretion in sinonasal cells by activating T1R2/3. d-Amino acid-mediated activation of T1R2/3 also enhanced epithelial cell death during challenge with Staphylococcus aureus in the presence of the bitter receptor-activating compound denatonium benzoate. These data establish a potential mechanism for interkingdom signaling in the airway mediated by bacterial d-amino acids and the mammalian sweet taste receptor in airway chemosensory cells.

Bacterial Ball as an Unusual Finding in Patients With Chronic Rhinosinusitis

OBJECTIVES

Pathophysiology of chronic rhinosinusitis (CRS) is very complex and has not yet been clearly understood. To date, various factors have been researched to have relations with the pathogenesis of CRS, such as superantigens and biofilms. Recently, we found an unusual pathological finding in patients with CRS, and we called this new entity as bacteria ball (or bioball). In this study, we analyze the clinical characteristics of bacteria ball occurred in CRS.

METHODS

This study enrolled consecutive 247 patients with CRS who underwent functional endoscopic sinus surgery from January 2015 to August 2016. The diagnosis of bacterial ball was made when negative in Gomori-methenamine-silver stain and positive in Gram stain. Histologically, bacterial ball was defined as acellular mucous materials with bacterial colonies and inflammatory cell infiltrates. We compared clinical data and computed tomography (CT) findings between fungal and bacterial balls.

RESULTS

Six cases (2.4%) of CRS were confirmed histologically as bacterial ball. Most of them were found in the maxillary sinus of CRS without nasal polyposis (66.7%). Bacterial ball was green or brown colored materials similar to fungal ball which was harder and tightly adherent to the antral mucosa. Compared to fungal ball, patients with bacterial ball showed significantly less peripheral eosinophils (P=0.011) and calcification in CT scans (P=0.003).

CONCLUSION

Bacterial ball is unusual findings occurred in patient with CRS which is different from fungal ball and biofilm. For diagnosis of bacterial ball, Gram stain is essentially required to identify bacterial colonies. Bacterial ball might appear to be evidence of a new strategy for living in the paranasal sinuses.

Flavones modulate respiratory epithelial innate immunity: Anti-inflammatory effects and activation of the T2R14 receptor

Chronic rhinosinusitis has a significant impact on patient quality of life, creates billions of dollars of annual healthcare costs, and accounts for ∼20% of adult antibiotic prescriptions in the United States. Because of the rise of resistant microorganisms, there is a critical need to better understand how to stimulate and/or enhance innate immune responses as a therapeutic modality to treat respiratory infections. We recently identified bitter taste receptors (taste family type 2 receptors, or T2Rs) as important regulators of sinonasal immune responses and potentially important therapeutic targets. Here, we examined the immunomodulatory potential of flavones, a class of flavonoids previously demonstrated to have antibacterial and anti-inflammatory effects. Some flavones are also T2R agonists. We found that several flavones inhibit Muc5AC and inducible NOS up-regulation as well as cytokine release in primary and cultured airway cells in response to several inflammatory stimuli. This occurs at least partly through inhibition of protein kinase C and receptor tyrosine kinase activity. We also demonstrate that sinonasal ciliated epithelial cells express T2R14, which closely co-localizes (<7 nm) with the T2R38 isoform. Heterologously expressed T2R14 responds to multiple flavones. These flavones also activate T2R14-driven calcium signals in primary cells that activate nitric oxide production to increase ciliary beating and mucociliary clearance. TAS2R38 polymorphisms encode functional (PAV: proline, alanine, and valine at positions 49, 262, and 296, respectively) or non-functional (AVI: alanine, valine, isoleucine at positions 49, 262, and 296, respectively) T2R38. Our data demonstrate that T2R14 in sinonasal cilia is a potential therapeutic target for upper respiratory infections and that flavones may have clinical potential as topical therapeutics, particularly in T2R38 AVI/AVI individuals.

Bacteriology of the Middle Meatus in Chronic Rhinosinusitis with and without Polyposis

There are only limited data in the literature, and none specifically from the Middle East, on the pathogenic bacteria in chronic rhinosinusitis (CRS) as opposed to healthy nasal cavities and their association with disease severity. The present study was conducted in the department of head and neck surgery of a tertiary medical center. Middle meatal swabs were taken preoperatively from patients with CRS with nasal polyposis (CRSwNP) (n = 60), CRS without nasal polyposis (CRSsNP) (n = 50), and control patients with septal deviation (n = 26) or no nasal abnormalities (n = 27). Culture findings were compared among the groups and correlated with CRS severity. Positive pathogenic culture rates were 78% in the CRSwNP group and 64% in the CRSsNP group. Twenty pathogenic bacterial species were identified; the most common was Staphylococcus aureus (27%). The most common Gram-negative isolate was Citrobacter spp. (17%). Gram-negative species were significantly more prevalent in the CRSwNP group than the others. Mean Lund-Mackay scores were 12.8 in the CRSwNP group and 6.9 in the CRSsNP group, and were unrelated to the culture findings. Positive culture rates were significantly higher in the septal deviation (54%) than the nasal healthy group (26%), although both values were significantly lower than in the CRS groups. In conclusion, patients with CRS have higher rates of bacterial isolates than patients without CRS. CRSwNP is associated with more Gram-negative bacteria than CRSsNP, regardless of disease severity. The relatively high positive culture rate in patients with septal deviation merits investigation.

In vitro effects of anthocyanidins on sinonasal epithelial nitric oxide production and bacterial physiology

BACKGROUND

T2R bitter taste receptors play a crucial role in sinonasal innate immunity by upregulating mucociliary clearance and nitric oxide (NO) production in response to bitter gram-negative quorum-sensing molecules in the airway surface liquid. Previous studies showed that phytochemical flavonoid metabolites, known as anthocyanidins, taste bitter and have antibacterial effects. Our objectives were to examine the effects of anthocyanidins on NO production by human sinonasal epithelial cells and ciliary beat frequency, and their impact on common sinonasal pathogens Pseudomonas aeruginosa and Staphylococcus aureus.

METHODS

Ciliary beat frequency and NO production were measured by using digital imaging of differentiated air-liquid interface cultures prepared from primary human cells isolated from residual surgical material. Plate-based assays were used to determine the effects of anthocyanidins on bacterial swimming and swarming motility. Biofilm formation and planktonic growth were also assessed.

RESULTS

Anthocyanidin compounds triggered epithelial cells to produce NO but not through T2R receptors. However, anthocyanidins did not impact ciliary beat frequency. Furthermore, they did not reduce biofilm formation or planktonic growth of P. aeruginosa. In S. aureus, they did not reduce planktonic growth, and only one compound had minimal antibiofilm effects. The anthocyanidin delphinidin and anthocyanin keracyanin were found to promote bacterial swimming, whereas anthocyanidin cyanidin and flavonoid myricetin did not. No compounds that were tested inhibited bacterial swarming.

CONCLUSION

Results of this study indicated that, although anthocyanidins may elicited an innate immune NO response from human cells, they do not cause an increase in ciliary beating and they may also cause a pathogenicity-enhancing effect in P. aeruginosa. Additional studies are necessary to understand how this would affect the use of anthocyanidins as therapeutics. This study emphasized the usefulness of in vitro screening of candidate compounds against multiple parameters of both epithelial and bacterial physiologies to prioritize candidates for in vivo therapeutic testing.

Dead or alive: Deoxyribonuclease I sensitive bacteria and implications for the sinus microbiome

BACKGROUND

Recently, there has been tremendous interest in the sinus microbiome and how it relates to disease. However, a lack of a standardized sample collection and DNA extraction methods makes comparison of results across studies nearly impossible. Furthermore, current techniques fail to identify which components of the microbiome are actually alive within the host at the time of sampling.

OBJECTIVE

To develop and optimize a method to differentiate which bacterial species in the human sinus microbiome are live versus dead.

METHODS

Duplicate samples from the middle meatus of patients with healthy sinus tissue and those patients with chronic rhinosinusitis were collected by using brushes (n = 12), swabs (n = 27), and tissue biopsy (n = 8) methods. One sample from each pair was either deoxyribonuclease I- or control-treated before DNA extraction. The relative bacterial versus human composition of each sample was determined. A 16S ribosomal RNA gene analysis was performed on a six-paired sample from patients with healthy sinus tissue.

RESULTS

We found that swabs and brushes collected a higher percentage of bacterial DNA than did tissue biopsy. We also determined that as much as 50% of the bacteria collected in these samples was already dead at the time of collection. The 16S ribosomal RNA gene analysis found significant changes in the relative abundance of taxa identified in the live versus dead bacterial communities of healthy human sinuses.

CONCLUSIONS

Our findings indicated that swabs provided the best quality microbiome samples and that a large portion of the bacteria identified in the sinus were deoxyribonuclease I sensitive. These results highlighted the need for improved techniques such as those presented here, which can differentiate between living and dead bacteria in a sample, a potentially critical distinction when examining changes in sinus innate immune function because both components play important, but distinct, functions. Further studies will determine how these living and dead bacterial populations shift in different disease states and after clinical intervention.

Sinonasal solitary chemosensory cells "taste" the upper respiratory environment to regulate innate immunity

BACKGROUND

It is not fully understood how sinonasal epithelial cells detect the presence of pathogens and activate innate defense responses necessary for protecting the upper airway from infection. One mechanism is through bitter taste receptors (T2Rs), which are expressed in the sinonasal cavity. One T2R isoform, T2R38, is expressed in ciliated cells and detects quorum-sensing molecules from gram-negative bacteria, activating antimicrobial nitric oxide production. More recent studies have examined the role of T2Rs expressed in a sinonasal cell type that has only recently been identified in humans, the solitary chemosensory cell (SCC). We sought to provide an overview of SCCs and taste receptor function in human sinonasal defense as well as implications for chronic rhinosinusitis (CRS).

METHODS

A literature review of the current knowledge of SCCs and taste receptors in sinonasal physiology and CRS was conducted.

RESULTS

Human sinonasal SCCs express both bitter T2R and sweet T1R2/3 receptors. Activation of SCC T2Rs activates a calcium signal that propagates to the surrounding epithelial cells and causes secretion of antimicrobial peptides. T1R2/3 sweet receptor activation by physiological airway surface liquid (ASL) glucose concentrations attenuates the T2R response, likely as a mechanism to prevent full activation of the T2R pathway except during times of infection, when pathogens may consume ASL glucose and reduce its concentration.

CONCLUSION

SCCs appear to be important mediators of upper airway innate immunity, as the SCC T2Rs regulate antimicrobial peptide secretion, but further study is needed to determine the specific T2R isoforms involved as well as whether polymorphisms in these isoforms affect susceptibility to infection or patient outcomes in CRS. The inhibitory role of T1R2/3 sweet receptor suggests that T1R2/3 blockers may have therapeutic potential in some CRS patients, particularly those with diabetes mellitus. However, further clinical study of the relationship between infection and T1R2/3 genotype is required.

Expression and Regulation of Interleukin-9 in Chronic Rhinosinusitis

Background

The pathogenesis of human chronic rhinosinusitis (CRS) remains controversial. Recent evidence has suggested that interleukin (IL)-9 is vital in eliciting inflammatory response, stimulating cell proliferation and preventing apoptosis, through binding to the IL-9 receptor (IL-9R). However, little is known about the roles of both molecules in the etiology of CRS. Therefore, this study aimed to assess IL-9 and IL-9R expression and determine their rolesin the pathophysiology of CRS.

Methods

Immunohistochemistry was used to assess IL-9 and IL-9R immunolabeling. In addition, Western blotting and real-time polymerase chain reaction (PCR) were used for IL-9 and IL-9R protein and mRNA level quantitation, respectively, in CRS and control subjects. Furthermore, the effects of various stimulators at different concentrations and time on IL-9 were evaluated using nasal explant cultures.

Results

IL-9 and IL-9R were overexpressed in CRS, especially in CRS with nasal polyps. Interestingly, IL-9 expression was closely related to that of IL-9R. In addition, IL-9 mRNA levels were increased by treatment with IL-4, IL-17A, IL-1beta, and the IL-4 and transforming growth factor (TGF) beta1 combination, but suppressed by interferon gamma and IL-27.

Conclusion

IL-9 and IL-9R were overexpressed in CRS at both protein and mRNA levels. In addition, IL-4, IL-17A, IL-1beta, and the IL-4 and TGF-beta1 combination contributed to increased IL-9 levels. Our findings indicate that IL-9 may play a proinflammatory role after IL-9R binding to induce mucosal epithelial cell growth, gland epithelial cell proliferation, and inflammatory cell infiltration in CRS. Future studies are required to further define the role of IL-9 in CRS etiology.

Taste receptors in innate immunity

Taste receptors were first identified on the tongue, where they initiate a signaling pathway that communicates information to the brain about the nutrient content or potential toxicity of ingested foods. However, recent research has shown that taste receptors are also expressed in a myriad of other tissues, from the airway and gastrointestinal epithelia to the pancreas and brain. The functions of many of these extraoral taste receptors remain unknown, but emerging evidence suggests that bitter and sweet taste receptors in the airway are important sentinels of innate immunity. This review discusses taste receptor signaling, focusing on the G-protein-coupled receptors that detect bitter, sweet, and savory tastes, followed by an overview of extraoral taste receptors and in-depth discussion of studies demonstrating the roles of taste receptors in airway innate immunity. Future research on extraoral taste receptors has significant potential for identification of novel immune mechanisms and insights into host-pathogen interactions.

The effectiveness topical amphotericin B in the management of chronic rhinosinusitis: a meta-analysis

Chronic rhinosinusitis (CRS) is believed to be the result of an exaggerated reaction to fungi in the nasal mucosa, and topical amphotericin B (AMB) is a commonly used treatment. The purpose of this study was to perform a meta-analysis of high-quality comparative studies to examine the efficacy of topical AMB for the treatment of CRS. A search was conducted of Medline, Cochrane, EMBASE, and ISI Web of Knowledge until December 31, 2013 using combinations of the search terms chronic rhinosinusitis, human, treatment, antibiotics, nasal irrigation, nebulized, nasal lavage, sinonasal rinses, and antimicrobials. Inclusion criteria were (1) comparative studies, (2) a diagnosis of CRS or chronic sinusitis, and (3) the intervention was a topical antifungal. The primary outcome measure was quality of life (QOL), and the secondary was nasal endoscopy score. Of 235 article initially identified, five randomized controlled trials were included in the meta-analysis. Analysis of four studies with complete QOL data found no difference between treatment and placebo groups [standard difference in means 0.78, 95 % confidence interval (CI) -0.25 to 1.81, P = 0.138]. Analysis of four studies with complete nasal endoscopy score data found no difference between the treatment and placebo groups (standard difference in means 0.34, 95 % CI -0.08 to 0.76, P = 0.117). AMB is not more effective than placebo in improving QOL or nasal endoscopy scores in patients with CRS.