Fungus as the cause of chronic rhinosinusitis: the case remains unproven

Noninvasive fungal rhinosinusitis: a case series

Introduction: Fungal rhinosinusitis (FRS) remains a rare disease. The noninvasive forms are hard to diagnose. The management protocols remain controversial. We aim to describe the clinical, radiological and pathological features of noninvasive FRS and present our management protocol and follow-up results. Patients and methods: This descriptive study was conducted in the ear-nose-throat department of the university hospital, Taher Sfar in Mahdia, Tunisia. All patients who responded to the definition of noninvasive FRS (fungal balls and allergic fungal sinusitis) were included. The study was conducted over a three year period (May 2017 – April 2021). Results: Eleven patients were included in this study: four cases of fungal balls and seven cases of allergic fungal sinusitis. Patients presented with symptoms of chronic recurrent rhinosinusitis with no response to conventional treatments. Computed tomodensitometry scan showed opacification of the paranasal sinuses in all patients. Other signs were heterogeneous opacities, local calcifications and thinning of the bony walls of the sinuses. Histopathological findings were inflammatory polyps in all cases of allergic FRS with the presence of fungal hyphae in 42.8% of the cases. All patients underwent surgery after a median delay of 12 [6–24] months of the symptom’s onset. The used procedures were endoscopic middle meatal antrostomy for all patients, ethmoidectomy (81.8%) and sphenoidotomy (36.4%). None received systemic antifungals or corticosteroids with a favorable outcome in all cases. Conclusion: Symptoms of noninvasive FRS are nonspecific. The scan images contribute to the diagnosis, but the perioperative findings and the histopathological results remain crucial.  The management is mainly surgical.

Dupilumab: An emerging therapy in allergic fungal rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is a highly resistant disease and is challenging to treat. Patients with recurrent attacks of the disease despite surgical management can benefit from biologics as adjunct therapies. Dupilumab has shown promising endpoints in patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). This case series reports 4 patients with resistant AFRS concomitant with asthma, for which dupilumab therapy was administered. Long-term follow-ups showed that dupilumab improved the symptoms and improved the results of objective tools such as imaging and pulmonary function test.

Chronic Diseases Associated with Malassezia Yeast

Malassezia are a lipid-dependent basidiomycetous yeast of the normal skin microbiome, although Malassezia DNA has been recently detected in other body sites and has been associated with certain chronic human diseases. This new perspective raises many questions. Are these yeasts truly present in the investigated body site or were they contaminated by other body sites, adjacent or not? Does this DNA contamination come from living or dead yeast? If these yeasts are alive, do they belong to the resident mycobiota or are they transient colonizers which are not permanently established within these niches? Finally, are these yeasts associated with certain chronic diseases or not? In an attempt to shed light on this knowledge gap, we critically reviewed the 31 published studies focusing on the association of Malassezia spp. with chronic human diseases, including psoriasis, atopic dermatitis (AD), chronic rhinosinusitis (CRS), asthma, cystic fibrosis (CF), HIV infection, inflammatory bowel disease (IBD), colorectal cancer (CRC), and neurodegenerative diseases.

Current understanding of allergic fungal rhinosinusitis

Studying the pathophysiology of allergic fungal rhinosinusitis (AFRS) has proved challenging. While this clinical entity is easily distinguishable based on the clinical criteria set forth by Bent and Kuhn twenty-five years ago, studies examining type 2 inflammatory profiles in AFRS can make it seem more alike other CRS subtypes than it is different. Still, evolving research seems to clearly delineate this subtype from others in CRS. This review will critically evaluate the evolution of research examining the pathophysiology of AFRS and will conclude with a summary of the special considerations in the management of this fascinating disease.

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.

A seven-year retrospective analysis of the clinicopathological and mycological manifestations of fungal rhinosinusitis in a single-centre tropical climate hospital

Objective:

To evaluate the clinicopathological and mycological manifestations of fungal rhinosinusitis occurring in the Tengku Ampuan Rahimah Hospital, in Klang, Malaysia, which has a tropical climate.

Methods:

Records of patients treated from 2009 to 2016 were analysed retrospectively. Data from the records were indexed based on age, gender, clinical presentations, symptom duration, clinical signs and mycological growth.

Results:

Of 80 samples, 27 (33.75 per cent) had fungal growth. Sixteen patients were classified as having non-invasive fungal rhinosinusitis and 11 as having invasive fungal rhinosinusitis. The commonest clinical presentation was nasal polyposis in non-invasive fungal rhinosinusitis patients (p < 0.05) and ocular symptoms in invasive fungal rhinosinusitis patients (p < 0.05). The commonest organism was aspergillus sp. (p < 0.05) in non-invasive fungal rhinosinusitis and mucorales in invasive fungal rhinosinusitis.

Conclusion:

There is an almost equal distribution of both invasive and non-invasive fungal rhinosinusitis, as seen in some Asian countries. Invasive fungal rhinosinusitis, while slightly uncommon when compared to non-invasive fungal rhinosinusitis, is potentially life threatening, and may require early and extensive surgical debridement. The clinical presentation of nasal polyposis was often associated with non-invasive fungal rhinosinusitis, whereas ocular symptoms were more likely to be associated with invasive fungal rhinosinusitis.

Candida Species Biofilms' Antifungal Resistance

Candida infections (candidiasis) are the most prevalent opportunistic fungal infection on humans and, as such, a major public health problem. In recent decades, candidiasis has been associated to Candida species other than Candida albicans. Moreover, biofilms have been considered the most prevalent growth form of Candida cells and a strong causative agent of the intensification of antifungal resistance. As yet, no specific resistance factor has been identified as the sole responsible for the increased recalcitrance to antifungal agents exhibited by biofilms. Instead, biofilm antifungal resistance is a complex multifactorial phenomenon, which still remains to be fully elucidated and understood. The different mechanisms, which may be responsible for the intrinsic resistance of Candida species biofilms, include the high density of cells within the biofilm, the growth and nutrient limitation, the effects of the biofilm matrix, the presence of persister cells, the antifungal resistance gene expression and the increase of sterols on the membrane of biofilm cells. Thus, this review intends to provide information on the recent advances about Candida species biofilm antifungal resistance and its implication on intensification of the candidiasis.

Allergic Aspergillus Rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is a unique variety of chronic polypoid rhinosinusitis usually in atopic individuals, characterized by presence of eosinophilic mucin and fungal hyphae in paranasal sinuses without invasion into surrounding mucosa. It has emerged as an important disease involving a large population across the world with geographic variation in incidence and epidemiology. The disease is surrounded by controversies regarding its definition and etiopathogenesis. A working group on "Fungal Sinusitis" under the International Society for Human and Animal Mycology (ISHAM) addressed some of those issues, but many questions remain unanswered. The descriptions of "eosinophilic fungal rhinosinusitis" (EFRS), "eosinophilic mucin rhinosinusitis" (EMRS) and mucosal invasion by hyphae in few patients have increased the problem to delineate the disease. Various hypotheses exist for etiopathogenesis of AFRS with considerable overlap, though recent extensive studies have made certain in depth understanding. The diagnosis of AFRS is a multi-disciplinary approach including the imaging, histopathology, mycology and immunological investigations. Though there is no uniform management protocol for AFRS, surgical clearing of the sinuses with steroid therapy are commonly practiced. The role of antifungal agents, leukotriene antagonists and immunomodulators is still questionable. The present review covers the controversies, recent advances in pathogenesis, diagnosis, and management of AFRS.

The clinical importance of fungal biofilms

Fungal biofilms have become an increasingly important clinical problem. The widespread use of antibiotics, frequent use of indwelling medical devices, and a trend toward increased patient immunosuppression have resulted in a creation of opportunity for clinically important yeasts and molds to form biofilms. This review will discuss the diversity and importance of fungal biofilms in the context of clinical medicine, provide novel insights into the clinical management of fungal biofilm infection, present evidence why these structures are recalcitrant to antifungal therapy, and discuss how our knowledge and understanding may lead to novel therapeutic intervention.

Aspergillus Biofilms in Human Disease

The biofilm phenotype of Aspergillus species is an important and accepted clinical entity. While industrially these biofilms have been used extensively in important biofermentations, their role in clinical infection is less well defined. A recent flurry of activity has demonstrated that these interesting filamentous moulds have the capacity to form biofilms both in vitro and in vivo, and through various investigations have shown that these are exquisitely resistant to antifungal therapies through a range of adaptive resistance mechanisms independent of defined genetic changes. This review will explore the clinical importance of these biofilms and provide contemporary information with respect to their clinical management.

The inflammatory response of eosinophil-related fungal rhinosinusitis varies with inciting fungi

Earlier studies demonstrated immunological response to Alternaria alternata in patients with eosinophil-related fungal rhinosinusitis (FRS). However, Aspergillus flavus rather than A. alternata is predominantly isolated from such patients in Asia. We compared immunological response to A. flavus and A. alternata in our patients with eosinophil related FRS. Total immunoglobulin E, absolute eosinophil count (AEC), cytokine response, and in vitro eosinophil degranulation in the presence of A. flavus/A. alternata were compared among patients with eosinophil-related FRS, non-eosinophilic rhinosinusitis (NECRS), and healthy individuals. Eosinophil-related FRS patients were subgrouped into: Group A - presence of mucin with fungus in tissues and positive immediate hypersensitivity; group B - presence of mucin with fungus in biopsies and no immediate hypersensitivity; and group C - presence of mucin without fungi and hypersensitivity. A. flavus was the predominant (89%) isolate. Significantly higher major basic protein (MBP) was induced by A. flavus in Group A (279.15 ± 32.29 ng/2.5 × 10(5) cells) compared to Group B (254.9 ± 17.14 ng), Group C (238.33 ± 17.56 ng), NECRS (56.96 ± 10.97 ng), and normal subjects (28.73 ± 7.04 ng). A. alternata - eosinophil interaction failed to induce detectable MBP. AEC and serum cytokines, interleukin (IL)- 2, IL-4, IL-5, IL-10, tumor necrosis factor α, and interferon-γ were significantly higher (P < 0.001) in eosinophil-related FRS compared to NECRS and control. Thus a mixed Th1 and Th2 cytokine response was observed in eosinophil-related FRS. In conclusion, immune response in eosinophil-related FRS depends on locally inciting fungi rather than A. alternata in all instances, and the categorization of this group appears to be arbitrary.

Frequency of fungal agents identified in sinus samples from patients with clinically suspected rhinosinusitis

Fungal rhinosinusitis (FRS) is one of the most important rhinosinusoidal disorders, which involves a variety of etiological agents. We carried out a study to determine the frequency of fungal agents in sinus samples from patients with clinically suspected rhinosinusitis (RS). A total of 205 clinical samples were assessed from 174 patients with clinically suspected RS, of which 48 were positive for microscopic examination and culture, 47 were positive for direct examination but negative by culture, 4 were negative for direct examination but positive by culture, and 106 were negative for both methodologies. The main fungal agents isolated were Aspergillus spp. (32.7%), followed by Schizophyllum commune (28.8%). Sensitivity and specificity of the direct examination were 92.3% and 69.3%, respectively, and concordance between the direct examination and culture was 48.4%. This study indicated that both Aspergillus and S. commune appear to be the most important agents involved in the development of FRS.

ICON: chronic rhinosinusitis

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

The molecular genetics of inflammatory, autoimmune, and infectious diseases of the sinonasal tract: a review

CONTEXT

The sinonasal tract is frequently affected by a variety of nonneoplastic inflammatory disease processes that are often multifactorial in their etiology but commonly have a molecular genetic component.

OBJECTIVE

To review the molecular genetics of a variety of nonneoplastic inflammatory diseases of the sinonasal tract.

DATA SOURCES

Inflammatory lesions of the sinonasal tract can be divided into 3 main categories: (1) chronic rhinosinusitis, (2) infectious diseases, and (3) autoimmune diseases/vasculitides. The molecular diagnosis and pathways of a variety of these inflammatory lesions are currently being elucidated and will shed light on disease pathogenesis and treatment.

CONCLUSIONS

The sinonasal tract is frequently affected by inflammatory lesions that arise through complex interactions of environmental, infectious, and genetic factors. Because these lesions are all inflammatory in nature, the molecular pathology surrounding them is most commonly due to upregulation and down-regulation of genes that affect inflammatory responses and immune regulation.

Medical management of allergic fungal rhinosinusitis following endoscopic sinus surgery: an evidence-based review and recommendations

BACKGROUND

Allergic fungal rhinosinusitis (AFRS) is a subset of polypoid chronic rhinosinusitis that is characterized by the presence of eosinophilic mucin with fungal hyphae within the sinuses and a Type I hypersensitivity to fungi. The treatment of AFRS usually involves surgery in combination with medical therapies to keep the disease in a dormant state. However, what constitutes an optimal medical regimen is still controversial. Hence, the purpose of this article is to provide an evidence-based approach for the medical management of AFRS.

METHODS

A systemic review of the literature on the medical management of AFRS was performed using Medline, EMBASE, and Cochrane Review Databases up to March 15, 2013. The inclusion criteria were as follows: patients >18 years old; AFRS as defined by Bent and Kuhn; post-sinus surgery; studies with a clearly defined end point to evaluate the effectiveness of medical therapy in postoperative AFRS patients.

RESULTS

This review identified and assessed 6 medical modalities for AFRS in the literature: oral steroids; topical steroids; oral antifungals; topical antifungals; immunotherapy; and leukotriene modulators.

CONCLUSION

Based on available evidence in the literature, postoperative systemic and standard topical nasal steroids are recommended in the medical management of AFRS. Nonstandard topical nasal steroids, oral antifungals, and immunotherapy are options in cases of refractory AFRS. No recommendations can be provided for topical antifungals and leukotriene modulators due to insufficient clinical research reported in the literature.

An evaluation of varying protocols for high-level disinfection of flexible fiberoptic laryngoscopes

OBJECTIVES/HYPOTHESIS

The use of flexible fiberoptic laryngoscopes (FFLs) is ubiquitous in otolaryngology practices. As with any medical device, there exists a small risk for transmission of pathogenic microorganisms between patients, necessitating high-level decontamination between uses. Most of the literature to date has studied channeled scopes such as those used in esophagogastroduodenoscopy and colonoscopy. A recent study of nonchanneled flexible laryngoscopes suggested that current high-level decontamination practices in use at some institutions, including ours, may be overly aggressive. We sought to evaluate and compare the efficacy of varying techniques of high-level disinfection of FFLs.

STUDY DESIGN

FFLs were used in routine clinical encounters and then disinfected with a variety of techniques. The FFLs were then cultured for bacteria and fungi, and the rates of positive cultures were compared between the techniques and the controls.

METHODS

In this study, we took FFLs following use in routine clinical practice and disinfected them using one of eight decontamination protocols. We compared the bacterial and fungal culture results to positive and negative controls.

RESULTS

We demonstrated that each of the eight cleaning protocols was statistically efficacious at removing bacterial contamination. Our results for fungal cultures did not reach statistical significance.

CONCLUSIONS

Using in vitro inoculation of FFLs, this study demonstrated that quicker and more cost-effective practices are equally efficacious to more time-consuming and expensive techniques with regard to bacterial contamination of FFLs.

LEVEL OF EVIDENCE

NA

The microbiome of chronic rhinosinusitis: culture, molecular diagnostics and biofilm detection

Background

Bacteria and fungi are believed to influence mucosal inflammation in chronic rhinosinusitis (CRS). However their presence and relationship to disease is debated. This study used multiple detection methods to compare microbial diversity and microbial abundance in healthy and diseased sinonasal mucosa. The utility of contemporary detection methods is also examined.

Methods

Sinonasal mucosa was analyzed from 38 CRS and 6 controls. Bacterial and fungal analysis was performed using conventional culture, molecular diagnostics (polymerase chain reaction coupled with electrospray ionization time-of-flight mass spectrometry) and fluorescence in situ hybridization.

Results

Microbes were detected in all samples, including controls, and were often polymicrobial. 33 different bacterial species were detected in CRS, 5 in control patients, with frequent recovery of anaerobes. Staphylococcus aureus and Propionibacterium acnes were the most common organisms in CRS and controls, respectively. Using a model organism, FISH had a sensitivity of 78%, and a specificity of 93%. Many species were detected in both CRS and controls however, microbial abundance was associated with disease manifestation.

Conclusions

This study highlights some cornerstones of microbial variations in healthy and diseased paranasal sinuses. Whilst the healthy sinus is clearly not sterile, it appears prevalence and abundance of organisms is critical in determining disease. Evidence from high-sensitivity techniques, limits the role of fungi in CRS to a small group of patients. Comparison with molecular analysis suggests that the detection threshold of FISH and culture is related to organism abundance and, furthermore, culture tends to select for rapidly growing organisms.

Role of fungi in the pathophysiology of chronic rhinosinusitis: an update

The pathogenesis of chronic rhinosinusitis (CRS) is multi-factorial with an infectious process likely at least partly involved. While bacteria have been proposed to play a critical role in CRS, fungi have also been implicated by some investigators, although the pathogenesis of fungi in CRS represents a significant controversy among rhinologists. Fungal-associated factors believed to be involved in CRS include the ability of fungi to induce significant inflammatory reactions by different means through inducing localized cytokine production in the sinonasal tract. Despite these observations, randomized, controlled studies on CRS patients using antifungal therapy have not resulted in significant improvement in CRS patients. The role of fungi in the pathogenesis of CRS remains controversial.

Bacterial-induced epithelial damage promotes fungal biofilm formation in a sheep model of sinusitis

BACKGROUND

Fungal biofilms have been discovered in chronic rhinosinusitis (CRS) patients, but factors contributing to their establishment are obscure. A recent animal study showed bacterial co-inoculation was required. We examine the role of 4 bacterial species and a cilia toxin on fungal biofilm formation in a sheep sinusitis model. The importance of epithelial integrity on fungal biofilm formation is also examined.

METHODS

Forty-eight frontal sinuses were inoculated with Aspergillus fumigatus alone, with 1 of 4 bacteria, or a cilia toxin. Bacterial and fungal biofilm was determined using confocal scanning laser microscopy. Inflammation and cilia integrity were assessed using light microscopy and transmission electron microscopy, respectively.

RESULTS

No fungal biofilm formed when inoculated alone. Florid fungal biofilm developed in more than 75% of sinuses associated with bacterial biofilm of all species, except Haemophilus influenzae, which failed to establish bacterial biofilm. Fungal biofilm also established in association with cilia toxin. Significant cilial damage was incited by all bacterial biofilms and cilia toxin, and was associated with fungal proliferation. Fungal biofilm formation did not significantly increase mucosal inflammation or epithelial damage over that caused by the bacteria or cilia toxin alone.

CONCLUSION

Bacterial biofilms cause sinonasal mucosal inflammation and epithelial injury, which provides conditions appropriate for fungal biofilm proliferation. The role of cilia in sinonasal mucosal defense against fungal organisms has been demonstrated. Without such an insult, fungal biofilms fail to proliferate in occluded sinuses. Improving cilial recovery postoperatively and treating bacterial biofilms may be key factors in reducing recalcitrance in allergic fungal rhinosinusitis patients.

Role of fungi in pathogenesis of chronic rhinosinusitis: the hypothesis rejected

PURPOSE OF REVIEW

Fungi have been suggested to play an important role in the pathogenesis of chronic rhinosinusitis (CRS). This review describes the recent knowledge concerning the role of fungi in the pathogenesis of CRS and allergic fungal rhinosinusitis (AFRS) and the clinical implications for treatment.

RECENT FINDINGS

Recent studies show that, although there are several potential deficits in the innate and potentially also in the acquired immunity of CRS patients that might reduce or change their ability to react to fungi, there are not many arguments to suggest a causative role for fungi in CRS with or without nasal polyps. However, due to the intrinsic or induced change in immunity of CRS patients, fungi might have a disease-modifying role. The fact that AFRS is more prevalent in warm and humid areas may point to fungi as a factor in this disease.

SUMMARY

Almost a decade after the launching of the hypothesis by Ponikau, the absence of convincing immunological data or evidence for clinical improvement of CRS upon therapy with antifungal agents now means that the hypothesis that fungi play a role in a majority of the cases of CRS has to be rejected and antifungal treatment should not be used.

Low SPINK5 expression in chronic rhinosinusitis

OBJECTIVES/HYPOTHESIS

Chronic rhinosinusitis (CRS) is a multifactorial disease that probably arises as a result of genetic diversity and environmental factors. SPINK5 is a serine protease inhibitor, which is supposed to be an important regulator of epithelial barrier maintenance. The role of SPINK5 polymorphisms and expression in CRS, especially in individuals with aspirin intolerance, is unclear.

STUDY DESIGN

SPINK5 single-nucleotide polymorphisms (SNPs) and SPINK5 expression levels were correlated with CRS without (CRSsNP) and with nasal polyps (CRSwNP), aspirin intolerance, asthma, and allergies.

METHODS

One hundred four nasal tissue samples, 15 from patients with CRSsNP, 59 from patients with CRSwNP, and 30 from healthy controls of the inferior turbinate, were analyzed for their SPINK5 status. Genotypes of four SPINK5 single nucleotide polymorphism (SNPs; G1258A, G2475T, A2915G, and A1103G), as well as SPINK5 mRNA expression levels, were determined by polymerase chain reaction.

RESULTS

No correlation between any SPINK5 SNP and CRSsNP, CRSwNP, or allergies and asthma was observed. The heterozygous SNPs G1258A and A1103G were observed more frequently in aspirin-intolerant patients; the homozygous (A/A) genotype of SNP 1258 and the homozygous (G/G) genotype SNP 1103 were less frequent. There was no correlation between the analyzed SNPs and the level of SPINK5 expression. It was noted that in individuals with CRSwNP, aspirin intolerance, and allergies, SPINK5 expression was lowered.

CONCLUSIONS

G1258A and A1103G polymorphisms are distinctive for the aspirin intolerance syndrome. Lowered SPINK5 expression might be a contributing factor leading to CRS, and appears to be characteristic for patients suffering from aspirin intolerance and from allergies.

Fungal rhinosinusitis: a retrospective microbiologic and pathologic review of 400 patients at a single university medical center

Fungal Rhinosinusitis (FRS) is a well known entity, but only in more recent times have the types of FRS been more fully defined. In this study, we evaluate the diagnosis of FRS in a single medical center. Cases were divided into 2 main categories, non-invasive and invasive. Non-invasive FRS included fungus ball (FB) and allergic fungal rhinosinusitis (AFRS). Invasive FRS included acute invasive fungal rhinosinusitis (AIFRS), chronic invasive fungal rhinosinusitis (CIFRS), and chronic invasive granulomatous fungal rhinosinusitis (CGFRS). Fungal culture data, if available was reviewed. 400 patients with FRS were identified. 87.25% were non-invasive (45% AFRS, 40% FB, and 2% combined AFRS and FB and 12.5% were invasive 11% AIFRS 1.2% CIFRS 0.5% CGFRS. One patient (0.25%) had combined FB/CGFRS. Aspergillus sp. or dematiaceous species were the most common fungi isolated in AFS while Aspergillus sp. was most common in FB and AIFRS. In our experience, most FRS is non-invasive. In our patient population, invasive FRS is rare with AIFRS representing >90% of cases. Culture data supports that a variety of fungal agents are responsible for FRS, but Aspergillus sp. appears to be one of the most common organisms in patients with FRS.

Aspergillus fumigatus biofilm on primary human sinonasal epithelial culture

BACKGROUND

Bacterial biofilms have been implicated in chronic rhinosinusitis (CRS). However, direct evidence in support of fungal biofilms in sinus disease is lacking in the literature. This study was designed to develop and characterize an in vitro Aspergillus fumigatus biofilm model on primary human sinonasal epithelial cell culture.

METHODS

Sinonasal biopsy specimens harvested during endoscopic sinus surgery of six CRS patients and three pituitary tumor (control) patients were cultured in Dulbecco's modified Eagle media (DMEM; Invitrogen)/Hams F12 airway media to encourage epithelial cell proliferation. Epithelial cells separated by immunomagnetic beads were seeded in tissue culture-treated Y-shaped microslides. At confluence the primary cultures were inoculated with A. fumigatus spores. Fungus was allowed to germinate and form biofilms under two in vitro conditions: (1) static (no flow through of media) and (2) continuous flow coculture (continuous flow movement of media). At regular intervals cocultures were stained with FUN-1, concanavalin A-alexa fluor 488, and examined by confocal scanning laser microscopy. Comstat software was used to assess biomass and thickness.

RESULTS

A. fumigatus formed three-dimensional biofilm structures with parallel-packed, cross-linked hyphae and channels/passages. Metabolically active hyphae showed orange-red fluorescing intravacuolar structures. Extracellular matrix (ECM) between/around the hyphae fluoresced intense green. A. fumigatus biofilms development occurred in five stages: (1) conidial attachment to epithelial cells, (2) hyphal proliferation, (3) ECM production, (4) hyphal parallel packing and cross-linking, and (5) channel/pores formation. Mature biofilms showed basal conidial, middle hyphal, and superficial ECM layers. Biofilms formed under flow conditions displayed more robust and faster growth kinetics when compared with that under static conditions, with a thick, stocky, wrinkly/undulating hyphal growth and extensive ECM production. The differences in biomass and average thickness of the cocultures under static and flow conditions were statistically significant after similar periods of incubation (p = 0.0002; p < 0.0001, respectively).

CONCLUSION

To our knowledge, this is the first article of an in vitro model characterizing A. fumigatus biofilm formation using primary human sinonasal epithelium under different growth conditions.

Antigen selection in IgE antibodies from individuals with chronic rhinosinusitis with nasal polyps

BACKGROUND

It is generally assumed that all immunoglobulin isotopes develop under antigen selection pressure, leading to dramatic increases in antigen-binding affinity. As activated B cells proliferate, somatic mutations accumulate in the regions of the immunoglobulin gene associated with antigen binding. Emerging evidence from studies investigating mutations in variable region sequences of IgE antibodies suggest that IgE may develop under less selection pressure than other isotypes. Recent studies have focused on IgE mutation patterns in sequences from the blood of allergic individuals. There is, however, little evidence of these patterns in IgE sequences isolated from tissue.

METHODS

Semi-nested reverse-transcription polymerase chain reaction was used to amplify the V region of IgE sequences from nasal tissue of individuals with chronic rhinosinusitis with nasal polyps (CRSwNPs). IgE sequences were analyzed for evidence of antigen selection and compared with previously reported IgE sequences from other inflammatory and allergic disorders and nonallergic individuals.

RESULTS

IgE sequences were successfully amplified from four individuals with CRSwNPs. Of 217 sequences amplified, 38 were unique, 31 of which were from tissue. Identification of the IGHV, IGHD, and IGHJ genes making up each sequence showed overrepresentation of an unusual gene in one individual, but otherwise normal gene usage. Mutation analysis revealed that only 5 of the 31 unique sequences from tissue show clear evidence of antigen selection.

CONCLUSION

With little influence from antigen selection, IgE antibodies are unlikely to be highly specific for antigens. Consequently, these findings have significant implications for the relevance of specific IgE, e.g., Staphylococcus aureus enterotoxin or fungal-specific IgE, in CRSwNP pathogenesis. Whether specific IgE expression is tightly related to pathogenesis or is merely a byproduct of B-cell interactions in local mucosa with colonizing organisms remains unresolved.

Fungus and chronic rhinosinusitis: weighing the evidence

The hypothesis that fungus causes most, if not all, cases of chronic rhinosinusitis (CRS) has been debated for over a decade. Many opinions and interpretations have been rendered, but it is the objective data that speaks the loudest. The debate simply boils down to a core tenet of the scientific method: Can the data be independently replicated? If so, our patients benefit as new treatments are developed. If not, then the hypothesis must be discarded and new lines of research pursued. Initial clinical trials supporting the fungal hypothesis have not been replicated in recent years by independent investigators. An attempt to independently replicate the basic science foundation of this hypothesis has also failed in a more heterogeneous group of CRS patients. The data can be dissected, reanalyzed, and reinterpreted and myriad arguments can be put forth. But an unbiased review of the data demonstrates that nearly every researcher outside of the original proponents of the fungal hypothesis has failed to replicate their work. The weight of the evidence is increasingly tipping the scales away from this theory.

Mold and human health: separating the wheat from the chaff

The term "mold" is utilized to define the ubiquitous fungal species commonly found in household dust and observed as visible multicellular filaments. Several well-defined human diseases are known to be caused or exacerbated by mold or by exposure to their byproducts. Among these, a solid connection has been established with infections, allergic bronchopulmonary aspergillosis, allergic fungal rhinosinusitis, hypersensitivity pneumonitis, and asthma. In the past decades, other less-defined and generally false conditions have also been ascribed to mold. We will herein review and critically discuss the available evidence on the influence of mold on human health.