Computer-Assisted Analysis of Oral Antifungal Therapy in Chronic Rhinosinusitis with Airway Mycosis: a Retrospective Cohort Analysis.

Environmental fungi are etiologically related to chronic rhinosinusitis (CRS) with airway mycosis, but their infectious role remains uncertain, in part because of potentially inadequate methods of disease quantitation. Our objective was to determine objective radiographic and symptomatic outcomes of oral antifungal therapy in adult patients with CRS and airway mycosis by using computer-assisted analysis. We conducted a retrospective study of 65 patients with CRS and culture-proven airway mycosis in a single-center referral-based academic practice, comparing paired sinus computed tomography (CT) scans and symptom scores prior to and during chronic oral antifungal therapy using computer-assisted analysis of sino-mucosal area (CAASMA). A comparator group received standard therapy without antifungals. Administration of antifungals was associated with significantly reduced sinus mucosal thickening as assessed by CAASMA (-6.85% absolute reduction; 95% confidence interval [CI], -11.8283 to -1.8717; P < 0.005), but not by Lund-Mackay score. In contrast, standard care alone was linked by CAASMA to enhanced mucosal thickening (4.14% absolute increase; 95% CI, -1.8066 to 10.0866; P < 0.005). Thirty of the 41 antifungal-treated patients (73%) showed decreased sinus mucosal burdens, while only 21 patients (43%) receiving standard therapy showed improved imaging (odds ratio [OR], 11.65; 95% CI, 3.2 to 42.2; P < 0.05). Nineteen patients (50%) noted improved symptoms at the time of a follow-up CT scan, while only 8 patients (20%) on standard therapy improved (OR, 6.21; 95% CI, 1.7 to 22.7; P < 0.05). These retrospective findings indicate that oral antifungals can reduce mucosal thickening and improve symptoms in CRS with airway mycosis. Randomized clinical trials are warranted to verify these findings.

Small molecule targeting of the STAT5/6 Src homology 2 (SH2) domains to inhibit allergic airway disease.

Asthma is a chronic inflammatory disease of the lungs and airways and one of the most burdensome of all chronic maladies. Previous studies have established that expression of experimental and human asthma requires the IL-4/IL-13/IL-4 receptor α (IL-4Rα) signaling pathway, which activates the transcription factor STAT6. However, no small molecules targeting this important pathway are currently in clinical development. To this end, using a preclinical asthma model, we sought to develop and test a small-molecule inhibitor of the Src homology 2 domains in mouse and human STAT6. We previously developed multiple peptidomimetic compounds on the basis of blocking the docking site of STAT6 to IL-4Rα and phosphorylation of Tyr641 in STAT6. Here, we expanded the scope of our initial in vitro structure-activity relationship studies to include central and C-terminal analogs of these peptides to develop a lead compound, PM-43I. Conducting initial dose range, toxicity, and pharmacokinetic experiments with PM-43I, we found that it potently inhibits both STAT5- and STAT6-dependent allergic airway disease in mice. Moreover, PM-43I reversed preexisting allergic airway disease in mice with a minimum ED50 of 0.25 µg/kg. Of note, PM-43I was efficiently cleared through the kidneys with no long-term toxicity. We conclude that PM-43I represents the first of a class of small molecules that may be suitable for further clinical development against asthma.

Advances and Evolving Concepts in Allergic Asthma.

Allergic asthma is a heterogeneous disorder that defies a unanimously acceptable definition, but is generally recognized through its highly characteristic clinical expression of dyspnea and cough accompanied by clinical data that document reversible or exaggerated airway constriction and obstruction. The generally rising prevalence of asthma in highly industrialized societies despite significant therapeutic advances suggests that the fundamental cause(s) of asthma remain poorly understood. Detailed analyses of both the indoor (built) and outdoor environments continue to support the concept that not only inhaled particulates, especially carbon-based particulate pollution, pollens, and fungal elements, but also many noxious gases and chemicals, especially biologically derived byproducts such as proteinases, are essential to asthma pathogenesis. Phthalates, another common class of chemical pollutant found in the built environment, are emerging as potentially important mediators or attenuators of asthma. Other biological products such as endotoxin have also been confirmed to be protective in both the indoor and outdoor contexts. Proasthmatic factors are believed to activate, and in some instances initiate, pathologic inflammatory cascades through complex interactions with pattern recognition receptors (PRRs) expressed on many cell types, but especially airway epithelial cells. PRRs initiate the release of proallergic cytokines such as interleukin (IL)-33, IL-25, and others that coordinate activation of innate lymphoid cells type 2 (ILC2), T helper type 2 cells, and immunoglobulin E-secreting B cells that together promote additional inflammation and the major airway remodeling events (airway hyperresponsiveness, mucus hypersecretion) that promote airway obstruction. Proteinases, with airway fungi and viruses being potentially important sources, are emerging as critically important initiators of these inflammatory cascades in part through their effects on clotting factors such as fibrinogen. Recent clinical trials have demonstrated that targeting inflammatory pathways orchestrated through IL-4, IL-5, IL-13, and the prostaglandin receptor CRTH2 is potentially highly effective in adult asthma.

The immune response to airway mycosis.

The allergic airway diseases chronic rhinosinusitis (CRS), allergic fungal rhinosinusitis (AFRS), asthma, allergic bronchopulmonary mycosis/aspergillosis (ABPM/A), and cystic fibrosis (CF) share a common immunological signature marked by TH2 and TH17 cell predominant immune responses, the production of IgE antibody, and a typical inflammatory cell infiltrate that includes eosinophils and other innate immune effector cells. Severe forms of these disorders have long been recognized as being related to hypersensitivity reactions to environmental fungi. Increasingly however,environmental fungi are assuming a more primary role in the etiology of these disorders, with airway mycosis, a type of non-invasive airway fungal infection, recognized as an essential driving factor in at least severe subsets of allergic airway diseases. In this review, we consider recent progress made in understanding the immune mechanisms that drive airway mycosis-related diseases, improvements in immune-based diagnostic strategies, and therapeutic approaches that target key immune pathways.

Transient Ascaris suum larval migration induces intractable chronic pulmonary disease and anemia in mice.

Ascariasis is one of the most common infections in the world and associated with significant global morbidity. Ascaris larval migration through the host's lungs is essential for larval development but leads to an exaggerated type-2 host immune response manifesting clinically as acute allergic airway disease. However, whether Ascaris larval migration can subsequently lead to chronic lung diseases remains unknown. Here, we demonstrate that a single episode of Ascaris larval migration through the host lungs induces a chronic pulmonary syndrome of type-2 inflammatory pathology and emphysema accompanied by pulmonary hemorrhage and chronic anemia in a mouse model. Our results reveal that a single episode of Ascaris larval migration through the host lungs leads to permanent lung damage with systemic effects. Remote episodes of ascariasis may drive non-communicable lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and chronic anemia in parasite endemic regions.

Mechanisms of allergy and adult asthma.

PURPOSE OF REVIEW: Allergic asthma reflects the interplay between inflammatory mediators and immune, airway epithelial, and other cells. This review summarizes key insights in these areas over the past year. RECENT FINDINGS: Key findings over the past year demonstrate that epithelial cells mediate tight junction breakdown to facilitate the development of asthma-like disease in mice. Innate lymph lymphoid cells (ILC), while previously shown to promote allergic airway disease, have now been shown to inhibit the development of severe allergic disease in mice. Fibrinogen cleavage products (previously shown to mediate allergic airway disease and macrophage fungistatic immunity by signaling through Toll-like receptor 4) have now been shown to first bind to the integrin Mac-1 (CD11c/CD18). Therapeutically, recent discoveries include the development of the antiasthma drug PM-43I that inhibits the allergy-related transcription factors STAT5 and STAT6 in mice, and confirmatory evidence of the efficacy of the antifungal agent voriconazole in human asthma. SUMMARY: Studies over the past year provide critical new insight into the mechanisms by which epithelial cells, ILC, and coagulation factors contribute to the expression of asthma-like disease and further support the development antiasthma drugs that block STAT factors and inhibit fungal growth in the airways.

Airway mycosis in allergic airway disease.

The allergic airway diseases, including chronic rhinosinusitis (CRS), asthma, allergic bronchopulmonary mycosis (ABPM) and many others, comprise a heterogeneous collection of inflammatory disorders affecting the upper and lower airways and lung parenchyma that represent the most common chronic diseases of humanity. In addition to their shared tissue tropism, the allergic airway diseases are characterized by a distinct pattern of inflammation involving the accumulation of eosinophils, type 2 macrophages, innate lymphoid cells type 2 (ILC2), IgE-secreting B cells, and T helper type 2 (Th2) cells in airway tissues, and the prominent production of type 2 cytokines including interleukin (IL-) 33, IL-4, IL-5, IL-13, and many others. These factors and related inflammatory molecules induce characteristic remodeling and other changes of the airways that include goblet cell metaplasia, enhanced mucus secretion, smooth muscle hypertrophy, tissue swelling and polyp formation that account for the major clinical manifestations of nasal obstruction, headache, hyposmia, cough, shortness of breath, chest pain, wheezing, and, in the most severe cases of lower airway disease, death due to respiratory failure or disseminated, systemic disease. The syndromic nature of the allergic airway diseases that now include many physiological variants or endotypes suggests that distinct endogenous or environmental factors underlie their expression. However, findings from different perspectives now collectively link these disorders to a single infectious source, the fungi, and a molecular pathogenesis that involves the local production of airway proteinases by these organisms. In this review, we discuss the evidence linking fungi and their proteinases to the surprisingly wide variety of chronic airway and systemic disorders and the immune pathogenesis of these conditions as they relate to environmental fungi. We further discuss the important implications these new findings have for the diagnosis and future therapy of these common conditions.

A Fungal Protease Model to Interrogate Allergic Lung Immunity.

Allergic airway diseases (asthma and chronic rhinosinusitis) are among the most common of all human diseases in heavily industrialized societies. Animal models of asthma have provided remarkable insight into allergic disease pathogenesis and will continue to drive the discovery of new therapeutic insights. We provide in this chapter a detailed protocol for inducing allergic immunity in the lungs of mice using a purified fungal protease and include related protocols for assessing immune endpoints.

Salt-bridging effects on short amphiphilic helical structure and introducing sequence-based short beta-turn motifs.

Determining the minimal sequence necessary to induce protein folding is beneficial in understanding the role of protein-protein interactions in biological systems, as their three-dimensional structures often dictate their activity. Proteins are generally comprised of discrete secondary structures, from α-helices to ß-turns and larger ß-sheets, each of which is influenced by its primary structure. Manipulating the sequence of short, moderately helical peptides can help elucidate the influences on folding. We created two new scaffolds based on a modestly helical eight-residue peptide, PT3, we previously published. Using circular dichroism (CD) spectroscopy and changing the possible salt-bridging residues to new combinations of Lys, Arg, Glu, and Asp, we found that our most helical improvements came from the Arg-Glu combination, whereas the Lys-Asp was not significantly different from the Lys-Glu of the parent scaffold, PT3. The marked 310-helical contributions in PT3 were lessened in the Arg-Glu-containing peptide with the beginning of cooperative unfolding seen through a thermal denaturation. However, a unique and unexpected signature was seen for the denaturation of the Lys-Asp peptide which could help elucidate the stages of folding between the 310 and α-helix. In addition, we developed a short six-residue peptide with ß-turn/sheet CD signature, again to help study minimal sequences needed for folding. Overall, the results indicate that improvements made to short peptide scaffolds by fine-tuning the salt-bridging residues can enhance scaffold structure. Likewise, with the results from the new, short ß-turn motif, these can help impact future peptidomimetic designs in creating biologically useful, short, structured ß-sheet-forming peptides.

Fungi in Mucoobstructive Airway Diseases.

Asthma, chronic rhinosinusitis, and related incurable allergic afflictions of the upper and lower airways are medically important because of their association with the disabling symptom of dyspnea and, at least for asthma, the potential to cause fatal asphyxiation. Extensive research over the past two decades has uncovered both the physiological basis of airway obstruction in asthma and key governing molecular pathways. Exaggerated airway constriction in response to diverse provocative stimuli, termed airway hyperresponsiveness, is mediated through the cytokines interleukin 4 (IL-4) and IL-13 and the transcription factor signal transducer and activator of transcription 6 (STAT6). Overproduction of mucus has long been known to be an essential second component of airway obstruction and is also mediated in part through the IL-4/IL-13/STAT6 pathway. In this review, we discuss a second major signaling pathway which underlies mucus production that is mediated through proteinase-cleaved fibrinogen signaling through Toll-like receptor 4. Unexpectedly, our analysis of human sputum and paranasal sinus fluid indicates that in most cases of severe allergic airway disease, a unique type of airway fungal infection, termed airway mycosis, is pathogenically linked to these conditions. We further discuss how fungal and endogenous proteinases mediate the fibrinogenolysis that is essential to both Toll-like receptor 4 signaling and fibrin deposition that, together with mucus, contribute to airway obstruction.

Benefits of antifungal therapy in asthma patients with airway mycosis: A retrospective cohort analysis.

INTRODUCTION: Fungal airway infection (airway mycosis) is increasingly recognized as a cause of asthma and related disorders. However, prior controlled studies of patients treated with antifungal antibiotics have produced conflicting results. Our objective is to measure the effect of antifungal therapy in moderate to severe adult asthmatics with positive fungal sputum cultures in a single center referral-based academic practice. METHODS: We retrospectively evaluated 41 patients with asthma and culture-proven airway mycosis treated with either terbinafine, fluconazole, itraconazole, voriconazole, or posaconazole for 4 to >12 weeks together with standard bronchodilator and anti-inflammatory agents. Asthma control (1 = very poorly controlled; 2 = not well controlled; and 3 = well controlled), peak expiratory flow rates (PEFR), serum total IgE, and absolute blood eosinophil counts before and after antifungal therapy were assessed. In comparison, we also studied nine patients with airway mycosis and moderate to severe asthma who received standard therapy but no antifungals. RESULTS: Treatment with azole-based and allylamine antifungals was associated with improved asthma control (mean change in asthma control 1.72-2.25; p = 0.004), increased PEFR (69.4% predicted to 79.3% predicted, p = 0.0011) and markedly reduced serum IgE levels (1,075 kU/L to 463 kU/L, p = 0.0005) and blood eosinophil counts (Mean absolute count 530-275, p = 0.0095). Reduction in symptoms, medication use, and relapse rates decreased as duration of therapy increased. Asthmatics on standard therapy who did not receive antifungals showed no improvement in asthma symptoms or PEFR. Antifungals were usually well tolerated, but discontinuation (12.2%) and relapse (50%) rates were relatively high. CONCLUSION: Antifungals help control symptoms in a subset of asthmatics with culture-proven airway mycosis. Additional randomized clinical trials are warranted to extend and validate these findings.

Allergen-encoded signals that control allergic responses.

PURPOSE OF REVIEW: The purpose is to review the important recent advances made in how innate immune cells, microbes, and the environment contribute to the expression of allergic disease, emphasizing the allergen-related signals that drive allergic responses. RECENT FINDINGS: The last few years have seen crucial advances in how innate immune cells such as innate lymphoid cells group 2 and airway epithelial cells and related molecular pathways through organismal proteinases and innate immune cytokines, such as thymic stromal lymphopoietin, IL-25, and IL-33 contribute to allergy and asthma. Simultaneously with these advances, important progress has been made in our understanding of how the environment, and especially pathogenic organisms, such as bacteria, viruses, helminths, and especially fungi derived from the natural and built environments, either promote or inhibit allergic inflammation and disease. Of specific interest are how lipopolysaccharide mediates its antiallergic effect through the ubiquitin modifying factor A20 and the antiallergic activity of both helminths and protozoa. SUMMARY: Innate immune cells and molecular pathways, often activated by allergen-derived proteinases acting on airway epithelium and macrophages as well as additional unknown factors, are essential to the expression of allergic inflammation and disease. These findings suggest numerous future research opportunities and new opportunities for therapeutic intervention in allergic disease.