Pediatric Allergic Fungal Sinusitis: A Clinical Review

Allergic fungal sinusitis (AFS) is the most common type of fungal sinus infection. AFS is a robust allergic reaction to inhaled soil fungi that causes sinus inflammation, and the fungal debris then accumulates in the sinus cavities. This accumulation can cause nasal polyps, facial pain and pressure, bone remodeling of the face, and even bone erosion, which can cause damage to the eyes and brain. AFS can also cause thick, sticky nasal mucus and postnasal drip, and it can affect the sense of smell. Most patients with AFS are adolescents who also have chronic symptoms of allergic rhinitis and asthma. Endoscopic sinus surgery to remove the disease and open the sinus cavities is the main treatment approach. Adjuvant immunotherapy is helpful in reducing the inflammatory response and preventing future recurrence of this allergy-mediated condition. [Pediatr Ann. 2021;50(7):e297-e303.].

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

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.

Innate immunity and chronic rhinosinusitis: What we have learned from animal models

OBJECTIVE

Chronic rhinosinusitis (CRS) is a heterogeneous and multifactorial disease characterized by dysregulated inflammation. Abnormalities in innate immune function including sinonasal epithelial cell barrier function, mucociliary clearance, response to pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs), and the contribution of innate immune cells will be highlighted in this review.

DATA SOURCES

PubMed literature review.

REVIEW METHODS

A review of the literature was conducted to determine what we have learned from animal models in relation to innate immunity and chronic rhinosinusitis.

RESULTS

Dysregulation of innate immune mechanisms including sinonasal barrier function, mucociliary clearance, PAMPs, and innate immune cells such as eosinophils, mast cells, and innate lymphoid cells may contribute to CRS pathogenesis. Sinonasal inflammation has been studied using mouse, rat, rabbit, pig, and sheep explant or in vivo models. Study using these models has allowed for analysis of experimental therapeutics and furthered our understanding of the aforementioned aspects of the innate immune mechanism as it relates to sinonasal inflammation. These include augmenting mucociliary clearance through activation of the cystic fibrosis transmembrane conductance regulator (CFTR) and study of drug toxicity on ciliary beat frequency. Knockout models of Toll-like receptors (TLR) have demonstrated the critical role these PRRs play in allergic inflammation as loss of TLR2 and TLR4 leads to decreased lower airway inflammation. Mast cell deficient mice are less susceptible to ovalbumin-induced sinonasal inflammation.

CONCLUSION

Animal models have shed light as to the potential contribution of dysregulated innate immunity in chronic sinonasal inflammation.

Vitamin D deficiency is associated with increased human sinonasal fibroblast proliferation in chronic rhinosinusitis with nasal polyps

BACKGROUND

Vitamin D3 (VD3) is a steroid hormone with known antiproliferative properties. Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have been shown to be VD3-deficient. Moreover, VD3 deficiency is associated with worse disease in patients with CRSwNP. One cell type thought to play a role in chronic rhinosinusitis (CRS) is the human sinonasal fibroblast (HSNF). The aim of this study was to investigate VD3 deficiency and HSNF proliferation in CRSwNP.

METHODS

Blood and sinus tissue explants were collected at the time of surgery from patients with CRSwNP (n = 15). Control subjects (n = 12) were undergoing surgery for cerebrospinal fluid leak repair or to remove non-hormone-secreting pituitary tumors. Ex vivo HSNF proliferation was analyzed with flow cytometry using expression of fibroblast-specific protein (FSP) and the proliferation marker Ki67. Plasma levels of 25-hydroxyvitamin D3 (25VD3) were measured by enzyme-linked immunosorbent assay. In vitro analysis of HSNF proliferation after treatment with calcitriol (1,25VD3) was performed using carboxyfluorescein succinimidyl ester (CFSE) and analyzed with flow cytometry.

RESULTS

In CRSwNP patients there was an inverse correlation between 25VD3 and proliferating HSNFs (p = 0.0135). This correlation was not seen for control patients (p = 0.3869). In vitro analysis showed that HSNFs from patients with CRSwNP had a higher proliferation index at baseline than HSNFs from control patients (p < 0.01). When treated with 1,25VD3, there was a significant decrease in HSNF proliferation index in patients with CRSwNP (p < 0.01), but not control patients.

CONCLUSION

VD3 deficiency is associated with increased HSNF proliferation in CRSwNP. Further investigation into how HSNFs and VD3 impact CRSwNP pathophysiology is warranted.

Mast Cell Deficiency Limits the Development of Chronic Rhinosinusitis in Mice

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most common chronic diseases in adults in both developing and developed countries. The etiology and pathogenesis of CRS remain poorly understood, and the disease is refractory to therapy in many patients. Mast cell activation has been demonstrated in the sinonasal mucosa of patients with CRS; however, the specific contribution of mast cells to the development and pathogenesis of this disease has not been established.

OBJECTIVE

The objective of this study was to investigate the role of mast cells in the development of CRS.

METHODS

C57BL/6 wild-type and C57BL/6-Kit(W-sh/W-sh) mast cell-deficient mice were immunized by intraperitoneal allergen injection and subsequent chronic low dose intranasal allergen challenges. The sinonasal phenotypes of these groups were then evaluated and compared to saline-treated controls using radiologic, histologic, and immunologic methods.

RESULTS

Wild-type mice exposed to chronic intranasal allergen developed many features seen in human CRS, including mucosal thickening, cystic changes, polyp development, eosinophilia, goblet cell hyperplasia, and mast cell activation. In contrast, sinonasal pathology was significantly attenuated in mast cell-deficient mice subjected to the same chronic allergen protocol. Specifically, tissue eosinophilia and goblet cell hyperplasia were reduced by approximately 50% compared to wild-type levels. Surprisingly, none of the mast cell-deficient mice subjected to chronic allergen challenge developed cystic changes or polypoid changes in the nose or sinuses.

CONCLUSIONS

These data identify a critical role for mast cells in the development of many features of a mouse model of eosinophilic CRS, suggesting that therapeutic strategies targeting mast cells be examined in humans afflicted with this disease.

Reduced sinonasal levels of 1α-hydroxylase are associated with worse quality of life in chronic rhinosinusitis with nasal polyps

BACKGROUND

Patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have deficiencies in circulating and sinonasal levels of the inactive form of vitamin D3, 25-hydroxycholecalciferol (25VD3). Moreover, CRSwNP patients have reduced epithelial cell-specific expression of 1α-hydroxylase; the enzyme responsible for the conversion of 25VD3 to its metabolically active form, 1α,25-dihydroxyvitamin D3 (1,25VD3). The objective of this work was to determine the impact of sinonasal 1α-hydroxylase levels combined from all cellular sources on subjective disease severity and to identify variables influencing its expression.

METHODS

Blood and sinus tissue explants were collected at the time of surgery from control, chronic rhinosinusitis without nasal polyps (CRSsNP), CRSwNP, and allergic fungal rhinosinusitis (AFRS) patients. 1α-Hydroxylase was measured by immunostaining with flow cytometric analysis. Subjective disease severity was measured by the 22-item Sino-Nasal Outcomes Test (SNOT-22). 1,25VD3 and 25VD3 were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Patients with CRSwNP or AFRS have reduced 1α-hydroxylase and 1,25VD3 compared to controls or CRSsNP. Circulating 1,25VD3 levels were the same among all groups. No differences in sinonasal 1α-hydroxylase or 1,25VD3 were found between CRSwNP and AFRS. Gender, age, race, atopy, and systemic 25VD3 had no impact on sinonasal 1α-hydroxylase levels in any group. However, CRSwNP patients with asthma had higher 1α-hydroxylase than those without asthma. Total 1α-hydroxylase levels inversely correlated with SNOT-22 in CRSwNP, but not CRSsNP.

CONCLUSION

Patients with CRSwNP and AFRS both have reduced sinonasal 1α-hydroxylase and 1,25VD3 compared to controls or CRSsNP. Reductions in intracellular 1α-hydroxylase combined from all sinonasal cell types were associated with more severe subjective disease severity in CRSwNP.

Identification of chronic rhinosinusitis phenotypes using cluster analysis

BACKGROUND

Current clinical classifications of chronic rhinosinusitis (CRS) have been largely defined based upon preconceived notions of factors thought to be important, such as polyp or eosinophil status. Unfortunately, these classification systems have little correlation with symptom severity or treatment outcomes. Unsupervised clustering can be used to identify phenotypic subgroups of CRS patients, describe clinical differences in these clusters and define simple algorithms for classification.

METHODS

A multi-institutional, prospective study of 382 patients with CRS who had failed initial medical therapy completed the Sino-Nasal Outcome Test (SNOT-22), Rhinosinusitis Disability Index (RSDI), Medical Outcomes Study Short Form-12 (SF-12), Pittsburgh Sleep Quality Index (PSQI), and Patient Health Questionnaire (PHQ-2). Objective measures of CRS severity included Brief Smell Identification Test (B-SIT), CT, and endoscopy scoring. All variables were reduced and unsupervised hierarchical clustering was performed. After clusters were defined, variations in medication usage were analyzed. Discriminant analysis was performed to develop a simplified, clinically useful algorithm for clustering.

RESULTS

Clustering was largely determined by age, severity of patient reported outcome measures, depression, and fibromyalgia. CT and endoscopy varied somewhat among clusters. Traditional clinical measures, including polyp/atopic status, prior surgery, B-SIT and asthma, did not vary among clusters. A simplified algorithm based upon productivity loss, SNOT-22 score, and age predicted clustering with 89% accuracy. Medication usage among clusters did vary significantly.

CONCLUSION

A simplified algorithm based upon hierarchical clustering is able to classify CRS patients and predict medication usage. Further studies are warranted to determine if such clustering predicts treatment outcomes.

Categorization and clinicopathological features of chronic rhinosinusitis with eosinophilic mucin in a korean population

Objectives

Chronic rhinosinusitis (CRS) with eosinophilic mucin is relatively rare in Korea. We categorized CRS patients with characteristic eosinophilic mucin into several groups and compared the groups based on their clinicopathological features.

Methods

In total, 52 CRS patients with eosinophilic mucin were enrolled. Based on the presence or absence of an allergy (A) to a fungus or fungal element (F) in the mucin, the patients were divided into four groups: allergic fungal rhinosinusitis (AFRS, A+F+), AFRS-like sinusitis (A+F-), eosinophilic fungal rhinosinusitis (EFRS, A-F+), and eosinophilic mucin rhinosinusitis (EMRS, A-F-). Clinical and immunological variables were compared between the groups.

Results

There were 13 patients in the AFRS group, 13 in the EFRS group, and 26 in the EMRS group. No patient was assigned to the AFRS-like sinusitis group. The AFRS group showed a significantly higher association with allergic rhinitis than did the EFRS and EMRS groups. The mean total serum IgE level in the AFRS patients was significantly higher than in the EFRS and EMRS patients. While 7.7% of the patients with AFRS and EFRS were asthmatic, 65.4% of the patients with EMRS had bronchial asthma. In the AFRS and EFRS groups, 31% had bilateral disease, in contrast to 100% of EMRS patients with bilateral disease. The prevalence of high attenuation areas by computed tomography was significantly higher in the AFRS group than in the EMRS group, and the mean Hounsfield unit values of the areas of high attenuation in the AFRS patients were significantly greater than those in the EMRS patients.

Conclusion

AFRS is believed to be an allergic response to colonizing fungi in atopic individuals. In EFRS, local allergies to fungi may play a role in the pathogenesis of the disease. EMRS is thought to be unconnected with fungal allergies.

Cigarette smoke exposure is associated with vitamin D3 deficiencies in patients with chronic rhinosinusitis

BACKGROUND

Cigarette smoke (CS) plays a role in the exacerbation of chronic rhinosinusitis (CRS); however, the mechanism for this is unknown. We hypothesize that CS impairs human sinonasal epithelial cell (HSNEC) conversion of 25(OH)D3 (25VD3) to 1,25-dihydroxyvitamin D3 (1,25VD3) and, furthermore, that supplementation with 1,25VD3 will reverse smoke-induced inflammatory responses by HSNECs.

OBJECTIVE

We sought to determine the effect of CS on vitamin D3 (VD3) levels, conversion, and regulation of CS-induced inflammation in control subjects and patients with CRS.

METHODS

Blood and sinus tissue explants were collected at the time of surgery from control subjects, patients with chronic rhinosinusitis without nasal polyps, and patients with chronic sinusitis with nasal polyps (CRSwNP). Expression of VD3 metabolizing enzymes were measured by using RT-PCR. Primary HSNECs were cultured from tissue explants. 25VD3 with and without cigarette smoke extract (CSE) was used to examine conversion of 25VD3 to 1,25VD3, as well as HSNEC production of proinflammatory cytokines.

RESULTS

CS exposure was associated with reduced circulating and sinonasal 25VD3 levels in all groups compared with those seen in CS-naive, disease-matched counterparts. CS exposure decreased expression of CYP27B1 and was especially pronounced in patients with CRSwNP. CSE impairs control HSNEC conversion of 25VD3. HSNECs from patients with CRSwNP also demonstrate an intrinsic reduction in conversion of 25VD3 to 1,25VD3. Exogenous 1,25VD3 reduces CSE-induced cytokine production by HSNECs.

CONCLUSIONS

Exposure to CS is associated with reduced 25VD3 levels and an impaired ability of HSNECs to convert 25VD3 to 1,25VD3. Addition of 1,25VD3 reduces the proinflammatory effects of CS on HSNECs. Impaired VD3 conversion by CS exposure represents a novel mechanism through which CS induces its proinflammatory effects.

Allergic sensitization in Canadian chronic rhinosinusitis patients

BACKGROUND

Chronic rhinosinusitis (CRS) is a societal burden and cause of morbidity in Canada; however, the prevalence of allergic sensitization in Canadian CRS patients has remained poorly characterized.

OBJECTIVE

In this study, we used skin prick test (SPT) and specific immunoglobulin E (sIgE) and G (sIgG) titers to regionally relevant allergen sources in order to determine whether allergic sensitization is more prevalent in CRS patients compared to chronic idiopathic urticaria (CIU) control patients.

METHODS

One hundred and fifty eight subjects (19-70 years of age) were recruited into the study. 101 subjects had a confirmed diagnostic history of CRS and 57 subjects with a clinical diagnosis of CIU were recruited as controls. Enrolled subjects underwent SPT to a panel of perennial and seasonal allergens and sIgE titers were quantified to selected environmental allergen mixes (grass, mold, and tree species) using Phadia ImmunoCAP. sIgG was additionally quantified to Alternaria alternata, Aspergillus versicolor, Cladosporium herbarum, and Stachybotrys atra. Differences between CRS and control CIU patient SPT and serological data were examined by chi-squared analysis and analysis of variance.

RESULTS

Reactivity to at least one SPT extract occurred in 73% of CRS patients. Positive SPT reactivity to A. alternata (odds ratio (OR): 4.34, 95% confidence interval: 1.57, 12.02), cat (OR: 3.23, 95% CI: 1.16, 9.02), and ragweed (OR: 2.31, 95% CI: 1.02, 5.19) extracts were more prevalent in patients with CRS (p < 0.05). Although dust mite and timothy grass sensitization approached statistical significance in the chi-squared analysis of SPT data, other common perennial and seasonal allergens were not associated with CRS. No statistically significant differences were observed between mean sIgE and sIgG titers in CRS and control patients.

CONCLUSIONS

This study supports previous data that suggests A. alternata sensitization is associated with CRS; however, these findings additionally highlight the contribution of other regionally important allergens including cat and ragweed.

Downregulation of polymeric immunoglobulin receptor and secretory IgA antibodies in eosinophilic upper airway diseases

BACKGROUND

Immunoglobulin (Ig) A represents a first-line defence mechanism in the airways, but little is known regarding its implication in upper airway disorders. This study aimed to address the hypothesis that polymeric Ig receptor (pIgR)-mediated secretory IgA immunity could be impaired in chronic upper airway diseases.

METHODS

Nasal and ethmoidal biopsies, as well as nasal secretions, were collected from patients with chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) or without nasal polyps (CRSsNP), allergic rhinitis (AR) and controls, and assayed for IgA1/IgA2 synthesis, pIgR expression, production of secretory component (SC), IgA and relevant IgA antibodies, and correlated with local eosinophils and inflammatory features (IL-12, IL-13 and ECP).

RESULTS

pIgR expression was decreased in the ethmoidal mucosa in patients with CRSwNP (P = 0.003) and in AR (P = 0.006). This pIgR defect was associated with reduced levels of SC (P = 0.007) and IgA antibodies to Staphylococcus aureus enterotoxin B (SAEB) (P = 0.003) in nasal secretions from patients with CRSwNP, and with increased IgA deposition in subepithelial areas. pIgR downregulation was selectively observed in patients with tissue eosinophilia, whilst no clear relation to smoking history was observed.

CONCLUSION

Epithelial pIgR expression is decreased in patients with CRSwNP and AR and results in decreased SC and IgA antibodies to certain bacterial antigens (SAEB) in nasal secretions of patients with CRSwNP in parallel to subepithelial accumulation of IgA. This defect in mucosal immunity is associated with eosinophilic, Th2-related inflammation.

Vitamin D3 deficiency increases sinus mucosa dendritic cells in pediatric chronic rhinosinusitis with nasal polyps

OBJECTIVE

Dendritic cells are professional antigen presenting cells, capable of initiating Th1 or Th2 responses, and have been implicated in the pathogenesis of a number of diseases, including sinusitis. Vitamin D(3) is a steroid hormone that acts on dendritic cells in a manner similar to corticosteroids. Investigators examined whether children with allergic fungal rhinosinusitis (AFRS) or chronic rhinosinusitis with nasal polyposis (CRSwNP) were vitamin D(3) deficient and the relationship of vitamin D(3) deficiency to dendritic cell infiltrate in the sinus mucosa.

SETTING

Tertiary care university hospital.

STUDY DESIGN

Retrospective, controlled study using samples collected from pediatric patients seen from August 2009 to July 2011.

SUBJECTS AND METHODS

Plasma levels of 25-hydroxy vitamin D(3) were measured by enzyme-linked immunosorbent assay in children (≤18 years old) with AFRS, CRSwNP, or CRS without nasal polyposis (CRSsNP) and in controls undergoing surgery for adenotonsillar hypertrophy. Vitamin D(3) levels were confirmed using clinical diagnostic methods for those with CRSwNP or AFRS. Tissue samples were immunohistochemically stained for the dendritic cell marker CD209 and the costimulatory molecules CD80 and CD86.

RESULTS

There was no difference in mean vitamin D(3) levels between control and CRSsNP, whereas mean CRSwNP and AFRS levels were both well below the minimum recommended level of 30 ng/mL and significantly lower than control and CRSsNP levels. CD209(+) dendritic cells inversely correlated with vitamin D(3) but not costimulatory molecule expression.

CONCLUSIONS

These studies identify that children with CRSwNP or AFRS are vitamin D(3) deficient, which may be linked to increased dendritic cell infiltrate. These results suggest a role for vitamin D(3) as a key player in the immunopathology of pediatric CRSwNP.

Structured histopathology profiling of chronic rhinosinusitis in routine practice

BACKGROUND

Tissue eosinophilia in chronic rhinosinusitis (CRS) is a marker of inflammatory disorders recalcitrant to surgical intervention. Eosinophilic chronic rhinosinusitis (ECRS) is traditionally associated with asthma, polyps, aspirin sensitivity, high serum eosinophilia, and elevated immunoglobulin E (IgE). However, patients with ECRS may not present with these associations and there is a need to establish other surrogate markers. The objective of the study was to determine the associations between the histopathology, serology, and clinical characteristics in CRS patients.

METHODS

A cross-sectional study was undertaken of CRS patients undergoing surgery. Tissue eosinophilia and other pathological features were compared to traditional surrogate features of ECRS, as well as to symptoms, and to radiologic and endoscopic scores.

RESULTS

A total of 51 patients were assessed (47% female, mean age 46.6 ± 4.1 years). High tissue eosinophilia (>10 per high-power field [HPF]) was more prominent in polyps (84%) (χ(2) = 25.76; p < 0.01) but was also seen in nonpolyp patients (19%). Asthma was not associated with high tissue eosinophilia (p = 0.60), with 43% of nonasthmatics demonstrating high tissue eosinophilia. Serum eosinophilia predicted high tissue eosinophilia at >0.30 × 10(9)/L or 4.4% of leukocytes (sensitivity 52%, specificity 87%, receiver operating characteristic [ROC] p = 0.001), with low negative predictive value. Serum IgE was nonpredictive (p = 0.08).

CONCLUSION

The diagnosis of ECRS has unique prognostic implications. Traditional features of the ECRS phenotype are not necessarily reliable markers for the presence of tissue eosinophilia. Serum eosinophilia may be a good surrogate marker of tissue eosinophilia but of limited use. The routine use of structured histopathology reporting in CRS is suggested, to allow for the diagnosis of ECRS and to identify other prognostic markers.

Necessary and sufficient role for T helper cells to prevent fungal dissemination in allergic lung disease

Mucosal immune responses to fungal infection range from T helper type 2 (Th2) cell-directed allergic inflammation to Th1-predominant neutrophilic inflammation, but the mechanisms directing these divergent mucosal immune outcomes and the role of T cells in host defense against mucosal fungal infections are not known. Here we examined the mouse mucosal immune responses to 12 filamentous environmental fungal species over a broad range of exposure doses and determined the requirement of T cells for host defense. For all tested fungi, low-grade conidium exposures induced Th2- and eosinophil-predominant allergic lung disease, whereas higher exposures led to rapid conversion to neutrophil- and Th1 cell-predominant inflammation, a phenomenon we term immune phenotype switching. All fungal exposure doses were further linked to the secretion of interleukin-17A (IL-17A). Fungal infections with Curvularia lunata and Aspergillus fumigatus were typically confined to the airway during allergic inflammation but became locally invasive and disseminated to the brain at higher conidium challenge doses, in association with predominant Th1 responses. Fungal dissemination occurred at relatively low challenge doses with the conidia of Aspergillus fumigatus administered to recombinase activating gene 1 (Rag-1)-deficient mice, which lack B and T cells, but B cell-deficient μMT mice and T helper cell-reconstituted Rag-1-deficient mice were comparable to wild-type mice in preventing fungal dissemination. Our findings demonstrate that Th2 cell-predominant allergic responses followed by immune phenotype switching and fungal dissemination are highly predictable outcomes with progressive fungal infectious burdens and that T helper cell responses are protective against lethal fungal dissemination.

Human sinonasal epithelial cells direct dendritic function and T-cell T helper 1/T helper 2 skewing following Aspergillus exposure

BACKGROUND

In lower airway disease such as asthma, epithelial cells have been shown to be potent regulators of dendritic cell (DC) functions. However, it is unclear how human sinonasal epithelial cells (HSNECs) from patients with sinusitis regulate DC functions. Therefore, in these studies we investigated the ability of Aspergillus fumigatus exposed HSNECs to regulate DC antigen uptake, maturation, and direction of T-cell T helper 1 (Th1)/Th2 skewing.

METHODS

Primary HSNECs were cultured from control (n = 8), chronic sinusitis without nasal polyps (CRSsNP) (n = 9), and chronic sinusitis with nasal polyps (CRSwNP) (n = 7) patients and exposed to Aspergillus. Conditioned media was placed upon monocyte-derived DCs from healthy controls. DC antigen uptake was assessed by dextran-fluorescein isothiocyanate (FITC) uptake. DC differentiation and maturation was assessed by immunostaining for CD209, CD80, and CD86 followed by flow cytometric analysis. DC direction of T-cell Th1/Th2 skewing was evaluated by immunostaining followed by intracellular flow cytometric analysis for interferon (IFN)-γ and interleukin (IL)-5.

RESULTS

Control and CRSsNP HSNECs have the capacity to stimulate DC antigen uptake, differentiation, and maturation following Aspergillus exposure. CRSwNP HSNECs stimulate DC activation independent of Aspergillus exposure. Furthermore, Aspergillus-exposed CRSwNP HSNECs skew T-cells toward a Th2 phenotype.

CONCLUSION

CRSwNP-derived HSNECs stimulate DC maturation and Th2 skewing independent of Aspergillus exposure. However, control and CRSsNP HSNECs induce DC maturation and Th2 skewing after Aspergillus exposure. These in vitro studies demonstrate that HSNECs are key regulators of DC functions in the sinus microenvironment.

Increased presence of dendritic cells and dendritic cell chemokines in the sinus mucosa of chronic rhinosinusitis with nasal polyps and allergic fungal rhinosinusitis

BACKGROUND

The aim of this study was to determine if there is a link between local dendritic cells (DCs) and various subtypes of chronic rhinosinusitis (CRS): CRS with nasal polyposis (CRSwNP), CRS without nasal polyposis (CRSsNP), and allergic fungal rhinosinusitis (AFRS). Once DC presence was established we considered possible mechanisms for DC recruitment to the sinuses.

METHODS

Biopsy specimens were taken from the osteomeatal complex during endoscopic sinus surgery in patients with AFRS (n ≥ 5), CRSsNP (n ≥ 6), and CRSwNP (n ≥ 6). Control patients (n ≥ 5) were undergoing either tumor resection or repair of cerebrospinal fluid leak and had no radiographic or endoscopic evidence of inflammatory sinus disease. Tissue samples were immunohistochemically stained for DC marker, CD209, costimulatory molecules, CD80 and CD86, and chemokine receptors, CCR2 and CCR6. Sinus tissue lysates were examined for levels of the DC chemoattractants, chemokine ligand 2 (CCL2) and CCL20.

RESULTS

Analysis of sinus tissue from AFRS and CRSwNP revealed elevated numbers of cells staining positive for CD209, CD80, CD86, CCR2, and CCR6 compared to controls. CCL2 and CCL20 levels were elevated in AFRS and CRSwNP compared to controls, similar to increases in their receptors, CCR2 and CCR6, respectively. While there were trends toward increases in all markers in CRSsNP, none was statistically significant compared to control.

CONCLUSION

AFRS and CRSwNP have increased numbers of DCs displaying costimulatory molecules, DC chemoattractants, and their corresponding receptors in the sinus mucosa compared to controls. These differences represent a possible mechanism for increased numbers of DCs with a T helper 2 (Th2)-skewed profile seen in CRSwNP and AFRS.

Seeking common pathophysiology in asthma, atopy and sinusitis

Asthma and chronic sinusitis are inexplicably common airway diseases that are linked to atopy and allergic inflammation. T helper type 2 (Th2) cells and the associated cytokines are believed to play crucial pathogenic roles in asthma, but the environmental factors that instigate allergic airway disease remain poorly understood. Environmental proteinases are highly allergenic and are candidate inducers of airway Th2 responses. Determining the proteinases and their sources that are relevant to airway disease, however, remains challenging. In this Opinion, we summarize the evidence that implicates fungi as both a relevant source of allergenic proteinases and a potential cause of asthma, atopy and chronic sinusitis through airway infection. Clarification of the extrinsic causes of these processes will markedly improve diagnosis, prognosis and therapy.

Local and systemic IgE in the evaluation and treatment of allergy

Traditional descriptions of type I hypersensitivity and its manifestations center on systemic immunoglobulin E (IgE)-mediated reactions to inciting antigens. Hence, many current diagnostic and therapeutic measures are based on systemic skin testing for allergy, systemic pharmacotherapy, and immunotherapy. Recent developments in rhinology and pulmonology, particularly in defining the phenomenon of local IgE production in various airway inflammatory conditions, have an impact on both medical and surgical diagnosis and management of these conditions. This review includes a discussion of allergy as a systemic disease, current systemic diagnostic and management strategies for allergy, and local IgE presence and synthesis in the upper and lower airways.

The role of allergy in rhinosinusitis

PURPOSE OF REVIEW

To examine the current evidence for IgE and non-IgE-mediated hypersensitivity mechanisms in acute and chronic rhinosinusitis.

RECENT FINDINGS

Epidemiological studies show that classical IgE-mediated allergy is present in a proportion of acute rhinosinusitis patients. There is conflicting evidence whether the prevalence of IgE-mediated allergy is greater in chronic rhinosinusitis than in individuals without chronic rhinosinusitis. Despite presence of classical IgE-mediated allergy, based on elevated allergen-specific serum IgE levels and positive skin prick tests, currently there is no direct evidence for allergy as a major cause of sinonasal inflammation in chronic rhinosinusitis. There is increasing evidence that non-IgE-mediated fungal hypersensitivity and nonallergic IgE-associated inflammation may contribute to the pathogenesis in some forms of chronic rhinosinusitis, including allergic fungal sinusitis. Specific IgE to bacterial superantigens may also be elevated in nasal polyps and modulate eosinophilic inflammation. Recent insights into mucosal immune mechanisms yield intriguing prospects for the roles of mucosal IgE, mast cells and non-IgE-mediated hypersensitivity mechanisms that require further examination in rhinosinusitis.

SUMMARY

There is a need for further immunological studies of the systemic and mucosal cellular and humoral mechanisms in well defined patient groups and controls to better understand the role of IgE and non-IgE-mediated hypersensitivity mechanisms and nonhypersensitivity functions of IgE in rhinosinusitis.

Localized immunoglobulin E expression in allergic rhinitis and nasal polyposis

PURPOSE OF REVIEW

This article reviews recent literature on local tissue identification of immunoglobulin E (IgE) in various sinonasal inflammatory conditions. Discussions of local IgE expression in allergic and nonallergic rhinitis, atopic and nonatopic sinonasal polyposis, and allergic fungal rhinosinusitis are included.

RECENT FINDINGS

Increased levels of IgE and positive reactivity on nasal allergen provocation tests have been demonstrated in nasal lavage fluid of patients with negative systemic allergy testing. In addition, elevated levels of Alternaria alternata-specific IgE have been identified in nasal polyp patients; this is hypothesized as a contributory factor in the development of nasal polyposis. Further evidence supports the role of local IgE to Staphylococcus aureus superantigens in atopic and nonatopic nasal polyposis. Finally, local IgE specific for a range of antigens has been identified in sinus and inferior turbinate tissue in patients with allergic fungal rhinosinusitis.

SUMMARY

Increased levels of IgE have been identified in sinonasal tissues in allergic and nonallergic rhinitis, atopic and nonatopic sinonasal polyposis, and allergic fungal rhinosinusitis. The ability to identify local tissue IgE in inflammatory sinonasal disease states may have significant diagnostic and therapeutic implications.

Antigen-specific IgE in Sinus Mucosa of Allergic Fungal Rhinosinusitis Patients

Background

Local tissue production of antigen-specific immunoglobulin E (IgE) has been shown in patients with allergic rhinitis and in patients with chronic rhinosinusitis (CRS) with nasal polyps. In allergic fungal rhinosinusitis (AFRS), specific IgE has been established in nasal lavage fluid and eosinophilic mucin. In this study, local production of antigen-specific IgE within sinus mucosa of AFRS patients was evaluated.

Methods

Sinus mucosa homogenates from 11 AFRS patients, 8 patients with CRS without nasal polyps (CRSsNP), and 9 nonrhinosinusitis control patients were assessed for IgE localization by immunohistochemistry. AFRS and control tissue homogenates were also evaluated for antigen-specific IgE to 14 common antigens by ImmunoCAP testing (Phadia AB, Portage, MI).

Results

There was a significant increase in IgE staining in AFRS sinus epithelium and subepithelium compared with controls and with patients with CRSsNP (p ≤ 0.012 for all group differences). AFRS patients showed increased IgE staining in the subepithelium when compared with epithelium (p < 0.001). AFRS sinus tissue had significantly more IgE measured by ImmunoCAP when compared with control sinus tissue for 7 of 14 specific antigens (p < 0.05) and for total IgE (p = 0.004). Antigens with a significant difference on ImmunoCAP included Cladosporium, Aspergillus, Timothy grass, red maple, cockroach, ragweed, and cocklebur.

Conclusion

AFRS patients showed significantly more IgE in sinus mucosa tissue specimens, with increased IgE in subepithelial sites when compared with epithelium. The increased expression of antigen-specific IgE is not limited to fungal antigens. These findings support the role of type I hypersensitivity and local manifestations of allergy in AFRS patients.

The cytology and microbiology of persistent paranasal sinus secretions after endoscopic sinus surgery: a controlled study

OBJECTIVE

To determine the cellular composition and influence of microbiology on persistent paranasal sinus secretions after endoscopic sinus surgery (ESS).

METHODS

Persistent sinus secretions from a consecutive series of patients after ESS were studied with cytopathology and cultures for aerobic, anaerobic, and fungal organisms. A control group consisting of patients without persistent secretions after ESS was also studied. Epithelial, neutrophil, and eosinophil cell presence was semiquantitatively assessed on a 4-point scale and compared between control and diseased groups. Cellular composition was then stratified and analyzed according to the presence of microorganisms.

RESULTS

A total of 50 diseased and 24 control patients were studied. Both diseased and control patients demonstrated sloughed epithelial cells in secretions (53.1% and 66.7%, respectively, P = .131). The diseased group exhibited significantly higher eosinophilic or eosinophilic/neutrophilic cellularity than the controls (P = .048). The average neutrophil infiltration score was 0.82 versus 0.54 for the controls (P = .104). For the diseased group, the mean eosinophil score was 1.56 versus 0.96 in the control group (P = .035). Pathogenic bacteria were identified in 64% of the diseased group patients versus 54.2% in controls (P = .454). Only two fungal cultures were positive (diseased group). Microbiological analysis indicated that in the absence of bacteria, diseased group patients mainly manifested an eosinophilic presence, whereas in the presence of bacteria, the neutrophil response was enhanced in diseased patients and eosinophil response was enhanced in controls.

CONCLUSIONS

Persistent sinus secretions after ESS are primarily driven by an eosinophilic presence. Patients without inflammatory exudate after ESS respond to bacteria with increased eosinophilia, whereas hypersecretory patients demonstrate both increased neutrophil and eosinophil presence.