Allergic fungal sinusitis: an immunohistologic analysis

Identification of Piecemeal Degranulation and Vesicular Transport of MBP-1 in Liver-Infiltrating Mouse Eosinophils During Acute Experimental Schistosoma mansoni Infection

Eosinophils have been long associated with helminthic infections, although their functions in these diseases remain unclear. During schistosomiasis caused by the trematode Schistosoma mansoni, eosinophils are specifically recruited and migrate to sites of granulomatous responses where they degranulate. However, little is known about the mechanisms of eosinophil secretion during this disease. Here, we investigated the degranulation patterns, including the cellular mechanisms of major basic protein-1 (MBP-1) release, from inflammatory eosinophils in a mouse model of S. mansoni infection (acute phase). Fragments of the liver, a major target organ of this disease, were processed for histologic analyses (whole slide imaging), conventional transmission electron microscopy (TEM), and immunonanogold EM using a pre-embedding approach for precise localization of major basic protein 1 (MBP-1), a typical cationic protein stored pre-synthesized in eosinophil secretory (specific) granules. A well-characterized granulomatous inflammatory response with a high number of infiltrating eosinophils surrounding S. mansoni eggs was observed in the livers of infected mice. Moreover, significant elevations in the levels of plasma Th2 cytokines (IL-4, IL-13, and IL-10) and serum enzymes (alanine aminotransferase and aspartate aminotransferase) reflecting altered liver function were detected in response to the infection. TEM quantitative analyses revealed that while 19.1% of eosinophils were intact, most of them showed distinct degranulation processes: cytolysis (13.0%), classical and/or compound exocytosis identified by granule fusions (1.5%), and mainly piecemeal degranulation (PMD) (66.4%), which is mediated by vesicular trafficking. Immunonanogold EM showed a consistent labeling for MBP-1 associated with secretory granules. Most MBP-1-positive granules had PMD features (79.0 ± 4.8%). MBP-1 was also present extracellularly and on vesicles distributed in the cytoplasm and attached to/surrounding the surface of emptying granules. Our data demonstrated that liver-infiltrating mouse eosinophils are able to degranulate through different secretory processes during acute experimental S. mansoni infections with PMD being the predominant mechanism of eosinophil secretion. This means that a selective secretion of MBP-1 is occurring. Moreover, our study demonstrates, for the first time, a vesicular trafficking of MBP-1 within mouse eosinophils elicited by a helminth infection. Vesicle-mediated secretion of MBP-1 may be relevant for the rapid release of small concentrations of MBP-1 under cell activation.

Th2 Immunological Inflammation in Allergic Fungal Sinusitis, Nonallergic Eosinophilic Fungal Sinusitis, and Chronic Rhinosinusitis

Background

Noninvasive fungal sinusitis is a heterogenous group of conditions including allergic fungal sinusitis (AFS) and nonallergic eosinophilic fungal sinusitis (NEFS). Th2-mediated cascades have been postulated to be the major inflammatory response in patients with AFS although other mechanisms also may be involved. The detailed mucosal Th2 cytological status of NEFS still has not been studied in great depth.

Methods

Using a meticulous patient selection algorithm over a 2-year period, infundibular mucosal tissue from patients with AFS, NEFS, chronic rhinosinusitis (CRS), and normal controls was studied (n = 59). Immunohistochemistry for mast cells, eosinophils, and immunoglobulin E (IgE) cells was performed and cell counts per unit area were measured.

Results

Mast cell, eosinophil, and IgE+ cell numbers were significantly raised in patients with AFS, NEFS, and CRS when compared with controls. There was no significant difference between cell numbers in patients with AFS and NEFS.

Conclusion

Patients with AFS exhibit a classic Th2 inflammatory response in nasal mucosal tissue with NEFS and CRS patients showing evidence of a similar Th2 cascade, including the presence of IgE+ cells.

Fungal DNA is Present in Tissue Specimens of Patients with Chronic Rhinosinusitis

Background

It has been postulated that fungal organisms might represent the immunologic target initiating and maintaining the disease process in patients with chronic rhinosinusitis (CRS). The presence of fungi in nasal mucus has been established by different groups, but so far it has not been shown how the immune system could even recognize such extramucosal—extracorporal—fungal targets. The aim of this study was to determine whether fungal DNA is present in tissue specimens taken from patients with polypoid CRS.

Methods

Twenty-seven surgical specimens were collected from patients suffering from CRS. Fifteen surgical specimens from healthy ethmoidal mucosa served as controls. A second set of controls consisted of five surgical specimens of acoustic neuroma, which were included to rule out contamination within the protocol. All paranasal tissue samples were treated and rinsed carefully with a solution of Dithiothreitol to digest any nasal mucus and ensure that only tissue was examined. A highly sensitive two-step polymerase chain reaction (PCR) was applied to detect fungal DNA, using one universal primer for unspecific detection of fungal DNA and a second primer pair specific for Alternaria.

Results

Fungal DNA was detected in all 27 CRS specimens equally with both PCR primers. Controls from healthy paranasal mucosa were positive using the panfungal primers in 10 of 15 cases but were all negative for Alternaria DNA. PCR was negative for fungal DNA in all five neuroma specimens.

Conclusions

Fungal DNA can be detected within sinonasal tissue specimens of patients suffering from CRS. These findings need to be discussed with respect to the proposed hypothesis of the immune system recognizing extramucosal organisms and initiating an immune response in sensitized patients.

Airway Manifestations of Pediatric Eosinophilic Esophagitis: A Clinical and Histopathologic Report of an Emerging Association

Objectives:

Pediatric eosinophilic esophagitis (EE) typically presents with dysphagia, vomiting, dyspepsia, or food impaction. The purpose of this study was to highlight the emerging association of pediatric EE and airway disease. An additional goal of this study was to describe the unique histopathologic findings found in EE and specifically explore the potential role of the cytotoxic protein called eosinophil major basic protein (MBP) in the pathophysiology of the disease.

Methods:

A retrospective review of 3 children with EE and airway symptoms included symptom presentation, aerodigestive tract endoscopic findings, ambulatory 24-hour dual pH-metry, allergy tests, treatment modalities, and treatment response. Esophageal tissue obtained from biopsies of each patient was evaluated by hematoxylin and eosin to determine the number of eosinophils per high-power field, by immunofluorescent anti-MBP staining to determine the presence of MBP, and by standard light and transmission electron microscopy to evaluate eosinophil migration patterns.

Results:

All patients had airway inflammation that included nonspecific laryngeal edema and grade I or II subglottic stenosis. Allergy testing was positive in the 2 patients who were tested. All patients had symptoms refractory to standard reflux therapy. Ambulatory pH-metry findings were normal in 2 patients and abnormal in 1 patient despite maximum treatment. Two patients had visual abnormalities seen during esophageal examination. The number of eosinophils ranged from 20 to 45 per high-power field. Intracellular and extracellular MBP deposition was found in all esophageal biopsy specimens. All patients were treated with swallowed fluticasone, and 2 had symptom relapses that required repeat treatment.

Conclusions:

The spectrum of pediatric EE can include upper airway disease. Intracellular and extracellular MBP deposition is present in EE, which potentially releases cytotoxic mediators that explain the esophageal and airway clinical symptoms seen in those with the disease. Eosinophilic esophagitis should be considered in patients with a history of atopic diseases and unexplained upper airway findings refractory to reflux treatment. Treatment with swallowed fluticasone is successful; however, relapses are common and require repeat treatment and close follow-up.

Effects of fungi and eosinophils on mucin gene expression in rhinovirus-infected nasal epithelial cells

Purpose

Fungi, rhinoviruses (RVs), and eosinophils are associated with upper respiratory diseases. We evaluated the effects of fungal stimulation and eosinophil co-culture on the expression of mucin genes in RV-infected nasal polyp epithelial cells.

Methods

Nasal polyp epithelial cells were obtained from chronic rhinosinusitis patients. Cultured epithelial cells were stimulated with Alternaria and Aspergillus with or without RV-16 infection. The epithelial cells were co-cultured with eosinophils for 16 h. MUC4, MUC5AC, MUC5B, and MUC8 mRNA expressions in the epithelial cells were quantified using real-time RT-PCR. To determine the underlying mechanism, nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and mitogen-activated protein kinase (MAPK) inhibitors were used to inhibit mucin gene expression.

Results

Fungi and RV-16 induced mucin gene expression in nasal polyp epithelial cells. However, there was no synergistic increase in mucin gene expression, with the exception of MUC4 mRNA expression stimulated by 25 µg/mL Aspergillus. When RV-16-infected epithelial cells were stimulated with fungi and then co-cultured with eosinophils, MUC4, MUC5B, and MUC8 mRNA expressions increased. Mucin gene expression was inhibited by NF-κB inhibitors.

Conclusions

RV-16, airborne fungi, and eosinophils may exacerbate the inflammatory process in nasal mucosal diseases by enhancing mucin gene expression.

Immunotherapy in allergic fungal sinusitis: The controversy continues. A recent review of literature

Allergic fungal sinusitis (AFS), also referred to as allergic fungal rhinosinusitis (AFRS), is a noninvasive, eosinophilic form of recurrent chronic allergic hypertrophic rhinosinusitis. AFS has distinct clinical, histopathological, and prognostic findings that differentiate it from other forms of sinusitis. The core pathogenesis and optimum treatment strategies remain debated. Concerns surround the use of immunotherapy for AFS because allergen-specific immunoglobulin G (IgG) induced by immunotherapy could theoretically incite a Gell and Coombs type III (complex mediated) reaction. Type I hypersensitivity is established by high serum levels of allergen-specific IgE to various fungal antigens and positive Bipolaris skin test results. Type III hypersensitivity is established by an IgG-mediated process defined by the presence of allergen-specific IgG that forms complexes with fungal antigen inducing an immunologic inflammatory response. These reveal the multiple immunologic pathways through which AFS can impact host responses. Recent literature establishing benefits of fungal immunotherapy and no evidence of type III–mediated reactions, severe local reactions, or delayed reactions, indicate that application of AFS desensitization is a reasonable therapeutic strategy for this difficult to manage entity. Our review should encourage further clinical acceptance of AFS desensitization because the existing literature on this subject shows benefits of fungal immunotherapy and no evidence of type III–mediated reactions, severe local reactions, or delayed reactions.

Potential contribution of fungal infection and colonization to the development of allergy

Fungi have long been recognized as an important source of allergens in patients with atopic disease. In this review, we explore the hypothesis that fungal exposures resulting in colonization or infection directly influence the tendency of an individual to develop allergic disease. According to this hypothesis, fungal exposures especially those early in life may influence the manner in which the immune response handles subsequent responses to antigen exposures. Studies detailing this potential connection between fungi have already provided important insights into the immunology of fungal-human interactions and offer the potential to provide new approaches and targets for the therapy of allergic disease. The first half of this review summarizes the data concerning fungal infections and asthma, including possible connections between fungal infections and urban asthma. The second half explores the potential role of the fungal gastrointestinal microbiota in promoting allergic inflammation.

Allergic fungal sinusitis: pathophysiology, diagnosis and management

Allergic fungal sinusitis (AFS) is a noninvasive form of fungal rhinosinusitis with an incidence of between 6 and 9% of all rhinosinusitis requiring surgery. Regional variation in incidence has been reported, with the southern and southwestern US particularly endemic. Patients with AFS commonly present with chronic rhinosinusitis with nasal polyps, inhalant atopy, elevated total serum immunoglobulin E (IgE), and sinus-obstructing inspissates of a characteristic extramucosal 'peanut buttery' visco-elastic eosinophil-rich material called 'allergic mucin' that contains sparse numbers of fungal hyphae. Sinus CT is always abnormal, showing findings of chronic rhinosinusitis that often include central areas of increased contrast ('hyperattenuation') within abnormal paranasal sinuses that represent the presence of fungal-containing allergic mucin. AFS has been found to be analogous in several ways to allergic bronchopulmonary aspergillosis (ABPA). Both are chronic inflammatory respiratory tract disorders that are driven by hypersensitivity responses to the presence of small numbers of extramucosal fungi found growing within airway-impacting allergic mucin. AFS allergic mucin typically cultures positive for either dematiaceous fungi such as Bipolaris spicifera or Curvularia lunata, or Aspergillus species such as A. fumigatus, A. flavus or A. niger. As with ABPA, patients have type I immediate hypersensitivity to the etiologic mold in AFS. Further, both AFS and ABPA have been found to have association with specific class II major histocompatibility alleles. Proper diagnosis of AFS and differentiation from the other forms of both noninvasive and invasive fungal rhinosinusitis requires strict adherence to published diagnostic criteria. Medical treatment of AFS has been modeled to an extent after treatment approaches for ABPA that includes the use of postoperative oral corticosteroids and aggressive antiallergic inflammation therapy. The use of follow-up measurements of total serum IgE during treatment of both AFS and ABPA patients can help to monitor disease activity. Future AFS research will lead to further insights into pathogenesis, improved treatments, and ultimately decreases in surgical recurrence rates for this highly recurrent hypertrophic rhinosinusitis disorder.

Allergic Fungal Rhinosinusitis

Allergic fungal rhinosinusitis (AFRS) is one of the more commonly encountered forms of noninvasive fungal rhinosinusitis, seen in immunecompetent individuals. It is caused by a Gell and Coombs Type I, IgE mediated (and possibly Type III) hypersensitivity reaction to an extramucosal fungal antigen. It bears striking similarities to Allergic Broncho Pulmonary Aspergillosis (ABPA), in terms of pathogenesis as well as treatment. It commonly presents as nasal polyposis. Most current treatment protocols for this condition are based on a combined medical and surgical approach. In this article we have recapitulated the history, epidemiology, etiology, clinical features, diagnostic investigations and treatment protocols for this disease.

Usefulness of Fungiflora Y to detect fungus in a frozen section of allergic mucin

Allergic fungal sinusitis is a non-invasive disease characterized by pansinusitis with nasal polyps, with most causative agents being members of the dematiaceous fungi. Reported herein is the ninth Japanese case of allergic fungal sinusitis; an Alternaria species was culturally identified as the etiological agent. The present patient, a 32-year-old man, presented with multiple sinusitis and nasal polyps. Allergic mucin, which is a histological hallmark of this disease, was examined intraoperatively on frozen section. Although characteristic histology, including laminated masses of mucin and aggregates of eosinophils, was seen in HE-stained sections, fungal hyphae were scarce and recognized merely as clear spaces. Because fluorescent stilbene derivatives seem useful for the rapid detection of fungi, Fungiflora Y, a commercially available staining kit that includes a fluorescent stilbene derivative, was applied to the sections, and hyphae were successfully visualized using a fluorescence microscope. This stain takes only several minutes to perform. It is concluded that Fungiflora Y should be used when fungal elements are hard to find on HE stain, especially in cases in which rapid detection of fungus is requested.

The role of fungi in the airway of chronic rhinosinusitis patients

PURPOSE OF REVIEW

To analyze the role of fungi in the upper and lower airway in chronic rhinosinusitis patients.

RECENT FINDINGS

Recently, the involvement of the lower airway (as asthma, small airway disease and bronchial hyperresponsiveness) in chronic rhinosinusitis patients had been documented. Fungal spores after inhalation are submerged in the aqueous lining layers of the airway. The site depends on the size of the inhaled spores. The process of inhalation, retention and clearance of fungal spores may explain the positive culture results in both normal subjects and in most chronic rhinosinusitis patients. Fungal culture of different parts of the upper and lower airway in chronic rhinosinusitis patients had no correlation with cellular changes (local eosinophilia) and other clinical parameters. In chronic rhinosinusitis, with persistence of the chronic inflammatory process, the cells may be activated nonspecifically.

SUMMARY

The role played by fungi in most chronic rhinosinusitis patients as the target antigen of initiation of such chronic inflammation is still debated. With the presence of chronic eosinophilic inflammation in chronic rhinosinusitis, an exaggerated reaction to various inhaled antigens is anticipated. The role of fungi will be confirmed only when T cells within the sinuses are shown to be actively responding to fungal antigens cultured from the sinus and with the demonstration that their elimination will stop the disease.

Allergic fungal sinusitis

Many common chronic inflammatory rhinosinusitis conditions (hypertrophic sinus disease [HSD]) have the histopathological profile of allergic or asthmatic inflammation. Allergic fungal sinusitis (AFS) is both a type of noninvasive fungal rhinosinusitis and a type of HSD. AFS has clinicopathological features that make it similar, but not identical, to allergic bronchopulmonary aspergillosis (ABPA). Allergic mucin is a defined pathological entity occurring in ABPA, AFS, and in the HSD "eosinophilic mucin rhinosinusitis (EMRS)." Diagnosis of AFS requires a careful review of surgical reports, histopathology, and culture results. Treatment includes surgery and aggressive postoperative medical management of allergic inflammatory disease. Prognosis is good with integrated medical-surgical follow-up, but recurrence remains problematic. The association of ABPA, AFS, and HSD with class II genes of the major histocompatibility complex places the initiation of these inflammatory diseases within the context of antigen presentation and the acquired immune response. Pathological immunomanipulation of this response by local microbial superantigens may be a common mechanism for disease pathogenesis. Future research into the molecular biology of these related conditions may offer insight into the pathogenesis of other chronic inflammatory diseases.

Allergic fungal sinusitis

Many common chronic inflammatory rhinosinusitis conditions (hypertrophic sinus disease [HSD]) have the histopathological profile of allergic or asthmatic inflammation. Allergic fungal sinusitis (AFS) is both a type of noninvasive fungal rhinosinusitis and a type of HSD. AFS has clinicopathological features that make it similar, but not identical, to allergic bronchopulmonary aspergillosis (ABPA). Allergic mucin is a defined pathological entity occurring in ABPA, AFS, and in the HSD "eosinophilic mucin rhinosinusitis (EMRS)." Diagnosis of AFS requires a careful review of surgical reports, histopathology, and culture results. Treatment includes surgery and aggressive postoperative medical management of allergic inflammatory disease. Prognosis is good with integrated medical-surgical follow-up, but recurrence remains problematic. The association of ABPA, AFS, and HSD with class II genes of the major histocompatibility complex places the initiation of these inflammatory diseases within the context of antigen presentation and the acquired immune response. Pathological immunomanipulation of this response by local microbial superantigens may be a common mechanism for disease pathogenesis. Future research into the molecular biology of these related conditions may offer insight into the pathogenesis of other chronic inflammatory diseases.

Allergic fungal sinusitis

AFS is an increasingly recognized form of HSD, now reported throughout the world. It is probably the most frequently occurring fungal rhinosinusitis disorder. The term fungal sinusitis is no longer appropriate because the five categories of fungal rhinosinusitis can now be differentiated. Each category of fungal rhinosinusitis disorder carries different treatment approaches and prognosis. Diagnostic error can be minimized by adhering to strict diagnostic criteria. The analogy (but not identity) of AFS to ABPA has been supported by histopathology, immunopathology, and the clinical response to OCS treatment. AFS represents a true medical surgical disorder in which both surgery and postoperative medical treatment, if properly coordinated between medical and surgical specialists, leads to the best patient outcomes. Continued advances in the understanding of the immunogenetics and immunopathogenesis of AFS may provide fundamental insights into molecular mechanisms operant in other chronic inflammatory disorders, including other chronic eosinophilic-lymphocytic respiratory mucosal disorders such as common forms of HSD and chronic severe asthma.

Allergic fungal sinusitis: pathogenesis and management strategies

Allergic fungal sinusitis (AFS) is a noninvasive form of highly recurrent chronic allergic hypertrophic rhinosinusitis that can be distinguished clinically, histopathologically and prognostically from the other forms of chronic fungal rhinosinusitis. There are three invasive (acute necrotising, chronic invasive and granulomatous invasive) and two noninvasive (fungal ball and allergic fungal) forms of fungal rhinosinusitis currently recognised. Confusion in differentiating between the various forms of fungal rhinosinusitis and between other forms of chronic hypertrophic sinus disease (HSD) can be eliminated by adhering to strict diagnostic criteria. Although there are characteristic presenting clinical history and physical examination findings, laboratory test results, including elevated total serum IgE and positive inhalant allergy skin tests, and sinus computed tomography scans showing chronic rhinosinusitis (often with the presence of hyperattenuating sinus contents) diagnosis of AFS is essentially based on histopathology obtained from sinus surgery. Histopathology shows the presence of eosinophilic-lymphocytic sinus mucosal inflammation, extramucosal allergic mucin (that is also seen grossly at surgery as a characteristic 'peanut-buttery' material), and scattered silver stain positive fungal hyphae within the allergic mucin but not in the mucosa. Treatment and follow up of AFS has been based on its immunopathological analogy to allergic bronchopulmonary aspergillosis, a similar noninvasive fungal hypersensitivity disorder of the lung, and its clinical and pathophysiological relationship to other forms of HSD and asthma. Treatment involves aggressive sinus surgery followed by medical management that includes allergen immunotherapy, topical and systemic corticosteroids, antihistamines and antileukotrienes. Total serum IgE levels should be followed postoperatively as they can be prognostic for recurrent disease. Close follow up and coordination of treatment by both medical and surgical physicians as a team leads to the best clinical outcomes. Ongoing studies are being directed at furthering our understanding of the pathophysiological relationships and treatment options for AFS, and other common forms of chronic hypertrophic rhinosinusitis disorders.

La Sinusite Fongique Allergique (SFA)

OBJECTIVES

Diagnosis, nosological individualization, and treatment of allergic fungal sinusitis remain difficult and controversial despite the increasing number of publications. We present ten cases of allergic fungal sinusitis and review the literature to highlight the main clinical, radiological, biological, immunoallergological, mycological, and therapeutics features.

MATERIAL AND METHODS

This retrospective study included ten patients (six men and four women, mean age 45 years) with allergic fungal sinusitis diagnosed on the basis of all diagnostic criteria reported in the literature.

RESULTS

Six patients had isolated allergic fungal sinusitis which was associated with allergic bronchopulmonary aspergillosis in the four others. Treatment combined endoscopic sinus surgery and corticosteroids, which provided good results in six patients and average results in three. Treatment failure was observed in one patient.

CONCLUSION

As in the case of allergic bronchopulmonary aspergillosis, a set of clinical, radiological, histopathological, immunoallergological and mycological criteria is necessary for precise diagnosis and to avoid fungal drift. The most appropriate endoscopic sinus surgery and the best corticosteroid regimen remain to be determined.

Role of allergy in rhinosinusitis

PURPOSE OF REVIEW

Allergic rhinitis and rhinosinusitis are common diseases occurring in both children and adults that consume enormous amounts of health care dollars. In addition to its own costs, allergic rhinitis is considered a major predisposing factor for the development of rhinosinusitis. Whereas many authors suggest a clinical association between these two diseases, the mechanism of how allergic rhinitis predisposes to rhinosinusitis or affects the course of rhinosinusitis remains unclear.

RECENT FINDINGS

Limited progress has been made in understanding the pathophysiologic mechanism involved in the interaction. Progress in immunologic technique emphasizes the importance of inflammatory cells, especially eosinophils, mast cells, and T lymphocytes, and their mediators. Some authors have proposed a role for neurogenic pathways, whereas others have focused on systemic involvement. Little progress has been made in intervention studies that support the importance of allergic rhinitis in altering the course of acute or chronic rhinosinusitis.

SUMMARY

This paper reviews the limited new literature available to update knowledge that supports the association of allergic rhinitis with rhinosinusitis, mechanisms potentially underlying the association, and implications of this knowledge for therapy.

Allergic fungal sinusitis: report of 3 cases and review of the literature

Allergic fungal sinusitis is a form of noninvasive fungal disease resulting from an IgE-mediated hypersensitivity reaction in atopic individuals. Allergic fungal sinusitis can present with a continuum of symptoms. Accumulation of allergic inspissated mucin may cause simple nasal obstruction or progress to facial deformity with osteolytic destruction and intracranial extension. Multiple species of fungi are now recognized as etiologic factors responsible for initiating the inflammatory response. This article discusses 3 cases involving Aspergillus and Curvularia species, and reviews diagnostic image findings, pathophysiology, and medical-surgical management of this increasingly common disease.

Symposium: masters in otolaryngology--update in rhinology

The past few years have witnessed several noteworthy advances in the field of rhinology in general and in the treatment of chronic sinusitis in particular. Many of these advances can be classified into three major trends: technology, techniques, and tissue eosinophilia.

The effect of nasal polyp epithelial cells on eosinophil activation

OBJECTIVES/HYPOTHESIS

Eosinophil infiltration into an inflammatory site is a characteristic histological finding in patients with chronic rhinosinusitis and nasal polyps. Most of the eosinophils in chronic rhinosinusitis are activated in the nasal cavity, but the exact activation mechanism of eosinophils is unknown. The study was designed to investigate the effect of human nasal epithelial cells on the activation of eosinophils.

STUDY DESIGN

Peripheral blood eosinophils were isolated from healthy volunteers and incubated in human nasal polyp epithelial cell conditioned media (HPECM). Superoxide production and eosinophil-derived neurotoxin were measured to determine eosinophils activation. HPECMs were assayed by ELISAs for interleukin-8 (IL-8), granulocyte-macrophage colony stimulating factor (GM-CSF), eotaxin, and regulated on activation normal T expressed and secreted (RANTES). To identify the chemical mediators involved in the activation of eosinophils.

RESULTS

HPECM (n = 7) contained 31.48 ng/mL interleukin-8, 533.43 pg/mL GM-CSF, 5.90 pg/mL eotaxin, and 11.06 pg/mL RANTES. Eosinophils were activated by HPECM and inhibited only by anti-GM-CSF antibody, not by the other chemical mediators.

CONCLUSION

The results suggest that eosinophils in nasal secretions are activated by GM-CSF, which is produced by nasal epithelial cells.

Sinobronchial allergic mycosis: the SAM syndrome

We contend that the presence of concomitant allergic fungal sinusitis (AFS) and allergic bronchopulmonary mycosis in the same patient represents an expression of the same process of fungal hypersensitivity in the upper and lower airways. We have termed this process the SAM syndrome, an acronym for sinobronchial allergic mycosis. Diagnostic criteria have been established for the SAM syndrome, and the clinical characteristics of one previously unreported and four previously reported patients have been tabulated. Patients with the SAM syndrome have chronic sinusitis involving multiple sinuses, asthma, immediate cutaneous reactivity to fungal allergens, peripheral eosinophilia, and radiographic evidence of bronchiectasis. Total serum IgE levels are usually elevated as well. A variety of chest radiographic abnormalities may occur, ranging from mass lesions to diffuse pulmonary infiltrates and even normal findings on chest radiographs. Patients present for an evaluation of either sinus or lung disease and, at that time, demonstrate no clinical features that distinguish them from patients with isolated sinus or lung disease. All patients reported to date have had clinical responses to therapy with corticosteroids. We postulate that SAM is underdiagnosed in patients with AFS, a disease recently reported from medical centers in the southeastern and western United States. Moreover, since our patient had a mutation in the cystic fibrosis transmembrane conductor regulator (CFTR) gene, we further hypothesize that CFTR gene mutations may play an important role in the pathogenesis of the SAM syndrome.

Eosinophil infiltration and degranulation in normal human tissues: evidence for eosinophil degranulation in normal gastrointestinal tract

Eosinophils play an important role in the pathogenesis of inflammatory diseases such as bronchial asthma and host immunity to parasitic infections. Deposition of eosinophil granule proteins and concomitant tissue damage have been documented in various diseases. Here, we review and summarize results of our immunofluorescence studies of eosinophil infiltration and degranulation in various normal human tissues. Furthermore, because eosinophil infiltration and degranulation are not normally present in healthy tissues, we examine whether eosinophil infiltration and degranulation normally occur in the small intestine and whether tissue procurement methods affect the extent of eosinophil infiltration and degranulation there. Hematopoietic and lymphatic tissues, including the thymus, showed eosinophil infiltration, but the only organ showing remarkable eosinophil infiltration and degranulation was the gastrointestinal (GI) tract. Eosinophil degranulation was significantly increased in specimens obtained by endoscopic forceps compared to those obtained by scalpel. These results suggest that tissue procurement methods affect the degree of eosinophil degranulation in the GI tract and that, among normal human body organs, both eosinophil infiltration and degranulation only occur in the GI tract.