Fungal allergy in asthma-state of the art and research needs

Saliva-controlled sputum culture (SSC) - A high value diagnostic tool for deep pulmonary infections

A major obstacle to prompt diagnosis of fungal pulmonary infections is that deep sputum samples are scarce, yet are frequently rejected if they contain saliva. We show that including saliva controls unfailingly distinguishes oropharyngeal flora from pulmonary fungi, thus preserving valuable samples for analysis, expediting diagnoses and improving patient care.

Aspergillus fumigatus Protease Alkaline Protease 1 (Alp1): A New Therapeutic Target for Fungal Asthma

We review three recent findings that have fundamentally altered our understanding of causative mechanisms underlying fungal-related asthma. These mechanisms may be partially independent of host inflammatory processes but are strongly dependent upon the actions of Alp1 on lung structural cells. They entail (i) bronchial epithelial sensing of Alp1; (ii) Alp1-induced airway smooth muscle (ASM) contraction; (iii) Alp1-induced airflow obstruction. Collectively, these mechanisms point to Alp1 as a new target for intervention in fungal asthma.

Respiratory microbiome and epithelial interactions shape immunity in the lungs

The airway epithelium represents a physical barrier to the external environment acting as the first line of defence against potentially harmful environmental stimuli including microbes and allergens. However, lung epithelial cells are increasingly recognized as active effectors of microbial defence, contributing to both innate and adaptive immune function in the lower respiratory tract. These cells express an ample repertoire of pattern recognition receptors with specificity for conserved microbial and host motifs. Modern molecular techniques have uncovered the complexity of the lower respiratory tract microbiome. The interaction between the microbiota and the airway epithelium is key to understanding how stable immune homeostasis is maintained. Loss of epithelial integrity following exposure to infection can result in the onset of inflammation in susceptible individuals and may culminate in lung disease. Here we discuss the current knowledge regarding the molecular and cellular mechanisms by which the pulmonary epithelium interacts with the lung microbiome in shaping immunity in the lung. Specifically, we focus on the interactions between the lung microbiome and the cells of the conducting airways in modulating immune cell regulation, and how defects in barrier structure and function may culminate in lung disease. Understanding these interactions is fundamental in the search for more effective therapies for respiratory diseases.

Exposure to mold proteases stimulates mucin production in airway epithelial cells through Ras/Raf1/ERK signal pathway

Environmental mold (fungus) exposure poses a significant threat to public health by causing illnesses ranging from invasive fungal diseases in immune compromised individuals to allergic hypertensive diseases such as asthma and asthma exacerbation in otherwise healthy people. However, the molecular pathogenesis has not been completely understood, and treatment options are limited. Due to its thermo-tolerance to the normal human body temperature, Aspergillus. fumigatus (A.fumigatus) is one of the most important human pathogens to cause different lung fungal diseases including fungal asthma. Airway obstruction and hyperresponsiveness caused by mucus overproduction are the hallmarks of many A.fumigatus induced lung diseases. To understand the underlying molecular mechanism, we have utilized a well-established A.fumigatus extracts (AFE) model to elucidate downstream signal pathways that mediate A.fumigatus induced mucin production in airway epithelial cells. AFE was found to stimulate time- and dose-dependent increase of major airway mucin gene expression (MUC5AC and MUC5B) partly via the elevation of their promoter activities. We also demonstrated that EGFR was required but not sufficient for AFE-induced mucin expression, filling the paradoxical gap from a previous study using the same model. Furthermore, we showed that fungal proteases in AFE were responsible for mucin induction by activating a Ras/Raf1/ERK signaling pathway. Ca2+ signaling, but ROS, both of which were stimulated by fungal proteases, was an indispensable determinant for ERK activation and mucin induction. The discovery of this novel pathway likely contributes to our understanding of the pathogenesis of fungal sensitization in allergic diseases such as fungal asthma.

The Role of Lung and Gut Microbiota in the Pathology of Asthma

Asthma is a common chronic respiratory disease affecting more than 300 million people worldwide. Clinical features of asthma and its immunological and molecular etiology vary significantly among patients. An understanding of the complexities of asthma has evolved to the point where precision medicine approaches, including microbiome analysis, are being increasingly recognized as an important part of disease management. Lung and gut microbiota play several important roles in the development, regulation, and maintenance of healthy immune responses. Dysbiosis and subsequent dysregulation of microbiota-related immunological processes affect the onset of the disease, its clinical characteristics, and responses to treatment. Bacteria and viruses are the most extensively studied microorganisms relating to asthma pathogenesis, but other microbes, including fungi and even archaea, can potently influence airway inflammation. This review focuses on recently discovered connections between lung and gut microbiota, including bacteria, fungi, viruses, and archaea, and their influence on asthma.

Detection of the 'Big Five' mold killers of humans: Aspergillus, Fusarium, Lomentospora, Scedosporium and Mucormycetes

Fungi are an important but frequently overlooked cause of morbidity and mortality in humans. Life-threatening fungal infections mainly occur in immunocompromised patients, and are typically caused by environmental opportunists that take advantage of a weakened immune system. The filamentous fungus Aspergillus fumigatus is the most important and well-documented mold pathogen of humans, causing a number of complex respiratory diseases, including invasive pulmonary aspergillosis, an often fatal disease in patients with acute leukemia or in immunosuppressed bone marrow or solid organ transplant recipients. However, non-Aspergillus molds are increasingly reported as agents of disseminated diseases, with Fusarium, Scedosporium, Lomentospora and mucormycete species now firmly established as pathogens of immunosuppressed and immunocompetent individuals. Despite well-documented risk factors for invasive fungal diseases, and increased awareness of the risk factors for life-threatening infections, the number of deaths attributable to molds is likely to be severely underestimated driven, to a large extent, by the lack of readily accessible, cheap, and accurate tests that allow detection and differentiation of infecting species. Early diagnosis is critical to patient survival but, unlike Aspergillus diseases, where a number of CE-marked or FDA-approved biomarker tests are now available for clinical diagnosis, similar tests for fusariosis, scedosporiosis and mucormycosis remain experimental, with detection reliant on insensitive and slow culture of pathogens from invasive bronchoalveolar lavage fluid, tissue biopsy, or from blood. This review examines the ecology, epidemiology, and contemporary methods of detection of these mold pathogens, and the obstacles to diagnostic test development and translation of novel biomarkers to the clinical setting.

Environment and Host-Genetic Determinants in Early Development of Allergic Asthma: Contribution of Fungi

Asthma is a chronic debilitating airway disease affecting millions of people worldwide. Although largely thought to be a disease of the first world, it is now clear that it is on the rise in many middle- and lower-income countries. The disease is complex, and its etiology is poorly understood, which explains failure of most treatment strategies. We know that in children, asthma is closely linked to poor lung function in the first 3-years of life, when the lung is still undergoing post-natal alveolarization phase. Epidemiological studies also suggest that environmental factors around that age do play a critical part in the establishment of early wheezing which persists until adulthood. Some of the factors that contribute to early development of asthma in children in Western world are clear, however, in low- to middle-income countries this is likely to differ significantly. The contribution of fungal species in the development of allergic diseases is known in adults and in experimental models. However, it is unclear whether early exposure during perinatal or post-natal lung development influences a protective or promotes allergic asthma. Host immune cells and responses will play a crucial part in early development of allergic asthma. How immune cells and their receptors may recognize fungi and promote allergic asthma or protect by tolerance among other immune mechanisms is not fully understood in this early lung development stage. The aim of this review is to discuss what fungal species are present during early exposure as well as their contribution to the development of allergic responses. We also discuss how the host has evolved to promote tolerance to limit hyper-responsiveness to innocuous fungi, and how host evasion by fungi during early development consequentially results in allergic diseases.

Associations between fungal and bacterial microbiota of airways and asthma endotypes

BACKGROUND

The relationship between asthma, atopy, and underlying type 2 (T2) airway inflammation is complex. Although the bacterial airway microbiota is known to differ in asthmatic patients, the fungal and bacterial markers that discriminate T2-high (eosinophilic) and T2-low (neutrophilic/mixed-inflammation) asthma and atopy are still incompletely identified.

OBJECTIVES

The aim of this study was to demonstrate the fungal microbiota structure of airways in asthmatic patients associated with T2 inflammation, atopy, and key clinical parameters.

METHODS

We collected endobronchial brush (EB) and bronchoalveolar lavage (BAL) samples from 39 asthmatic patients and 19 healthy subjects followed by 16S gene and internal transcribed spacer-based microbiota sequencing. The microbial sequences were classified into exact sequence variants. The T2 phenotype was defined by using a blood eosinophil count with a threshold of 300 cells/μL.

RESULTS

Fungal diversity was significantly lower in EB samples from patients with T2-high compared with T2-low inflammation; key fungal genera enriched in patients with T2-high inflammation included Trichoderma species, whereas Penicillium species was enriched in patients with atopy. In BAL fluid samples the dominant genera were Cladosporium, Fusarium, Aspergillus, and Alternaria. Using generalized linear models, we identified significant associations between specific fungal exact sequence variants and FEV1, fraction of exhaled nitric oxide values, BAL fluid cell counts, and corticosteroid use. Investigation of interkingdom (bacterial-fungal) co-occurrence patterns revealed different topologies between asthmatic patients and healthy control subjects. Random forest models with fungal classifiers predicted asthma status with 75% accuracy for BAL fluid samples and 80% accuracy for EB samples.

CONCLUSIONS

We demonstrate clear differences in bacterial and fungal microbiota in asthma-associated phenotypes. Our study provides additional support for considering microbial signatures in delineating asthma phenotypes.

Supporting self-management of asthma through patient education

Asthma affects people worldwide. In developed countries 1 in 12 individuals suffer from asthma, while in Ireland this ratio is closer to 1 in 10. Managing asthma symptoms and triggers reduces the potential exacerbation of asthmatic attacks. This article identifies the importance of asthma management, triggers, inhaler techniques and self-management for optimal health. Education by nurses and health professionals can make a significant contribution to asthma care and self-management. The purpose of patient education for self-management of asthma is twofold: to raise awareness of effective inhaler technique and to support self-management of asthma triggers for health and symptom control.

Bitter Taste Receptors: an Answer to Comprehensive Asthma Control?

PURPOSE OF REVIEW

Asthma is marked by peculiar pathological features involving airway contraction, an impinging inflammation in the lungs, and an inexorably progressive remodeling of pulmonary architecture. Current medications for management of asthma exacerbations fail to optimally mitigate these pathologies, which is partly due to the intrinsic heterogeneity in the development and progression of asthma within different populations. In recent years, the discovery of the ectopic expression of TAS2Rs in extraoral tissues and different cell types, combined with significant strides in gaining mechanistic understanding into receptor signaling and function, has revealed the potential to target TAS2Rs for asthma relief.

RECENT FINDINGS

TAS2R activation leads to relaxation of airway smooth muscle cells and bronchodilation. In addition, findings from preclinical studies in murine model of asthma suggest that TAS2R agonists inhibit allergen-induced airway inflammation, remodeling, and hyperresponsiveness. In this review, we expand on the opportunity presented by TAS2Rs in the development of a comprehensive asthma treatment that overcomes the limitations set forth by current asthma therapeutics.

Mold Sensitization in Asthmatic and Non-asthmatic Subjects Diagnosed with Extract-Based Versus Component-Based Allergens

Asthmatic patients are suspected of having a higher risk of mold sensitization. Thus, precise diagnosis of fungal sensitization is important. Mold allergen extracts are difficult to standardize, but component-resolved allergy diagnosis may be an alternative to replace extract-based tests. In this research, asthmatic and non-asthmatic subjects were studied for their sensitization to Aspergillus fumigatus (Asp f), Cladosporium herbarum (Cla h), Penicillium chrysogenum (Pen ch), Alternaria alternata (Alt a), and Aspergillus versicolor (Asp v). Extract-based tests were applied using the skin prick test (SPT) and allergen-specific immunoglobulin E (sIgE). Subjects with extract-based sensitization to Asp f or Alt a were further investigated for sIgE response to recombinant (r) single mold allergens. At least one mold sensitization was found in about 50% of asthmatic and non-asthmatics with the most frequent sensitization to Alt a, followed by Pen ch, Asp f, Cla h, and Asp v. Interestingly, sensitization rate to individual mold species was always higher in asthmatics and was only significant for Pen ch. The component-resolved diagnosis with the sum of rAsp f 1 - rAsp f 4 plus rAsp f 6 matched the extract-based results (SPT and/or sIgE) in 50% of asthmatics and 46% of non-asthmatics, whereas, rAlt a 1 covered 59% of asthmatics and 50% non-asthmatics of extract-based Alt a sensitization. In conclusion, individual fungal sensitization rate was higher in asthmatics compared to non-asthmatics. Extract-based tests, especially SPTs, were most sensitive, but component-based tests covered 80% of extract-based serological sensitization to Alternaria and Aspergillus.

Estimated Burden of Fungal Infections in Namibia

Namibia is a sub-Saharan country with one of the highest HIV infection rates in the world. Although care and support services are available that cater for opportunistic infections related to HIV, the main focus is narrow and predominantly aimed at tuberculosis. We aimed to estimate the burden of serious fungal infections in Namibia, currently unknown, based on the size of the population at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports. When no data existed, risk populations were used to estimate the frequencies of fungal infections, using the previously described methodology. The population of Namibia in 2011 was estimated at 2,459,000 and 37% were children. Among approximately 516,390 adult women, recurrent vulvovaginal candidiasis (≥4 episodes /year) is estimated to occur in 37,390 (3003/100,000 females). Using a low international average rate of 5/100,000, we estimated 125 cases of candidemia, and 19 patients with intra-abdominal candidiasis. Among survivors of pulmonary tuberculosis (TB) in Namibia 2017, 112 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 354 post-TB and a total prevalence estimate of 453 CPA patients in all. Asthma affects 11.2% of adults, 178,483 people, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) were estimated in approximately 179/100,000 and 237/100,000 people, respectively. Invasive aspergillosis (IA) is estimated to affect 15 patients following leukaemia therapy, and an estimated 0.13% patients admitted to hospital with chronic obstructive pulmonary disease (COPD) (259) and 4% of HIV-related deaths (108) — a total of 383 people. The total HIV-infected population is estimated at 200,000, with 32,371 not on antiretroviral therapy (ART). Among HIV-infected patients, 543 cases of cryptococcal meningitis and 836 cases of Pneumocystis pneumonia are estimated each year. Tinea capitis infections were estimated at 53,784 cases, and mucormycosis at five cases. Data were missing for fungal keratitis and skin neglected fungal tropical diseases such as mycetoma. The present study indicates that approximately 5% of the Namibian population is affected by fungal infections. This study is not an epidemiological study—it illustrates estimates based on assumptions derived from similar studies. The estimates are incomplete and need further epidemiological and diagnostic studies to corroborate, amend them, and improve the diagnosis and management of these diseases.

The Burden of Serious Fungal Infections in Tajikistan

Tajikistan is a low-income country in Middle Asia with a population of 8.9 million people. Five percent of the population lives on less than 1.9 USD a day and 54% live on less than 5.5 USD a day. We have estimated the burden of serious fungal infections in Tajikistan. It was estimated that 168,834 Tajik women develop recurrent vulvovaginal candidiasis. Among HIV-positive patients, we estimate 490 patients with oesophageal candidiasis and 1260 patients with oral candidiasis, 41 cases of cryptococcal meningitis and 210 cases of Pneumocystis pneumonia annually. According to our estimations there are 774 cases of chronic pulmonary aspergillosis (CPA) as a sequel of tuberculosis; CPA may occur as a consequence of multiple pulmonary conditions and the total prevalence of 4161 cases was estimated. We have estimated 6008 cased of allergic bronchopulmonary aspergillosis (ABPA) and 7930 cases of severe asthma with fungal sensitisation (SAFS), and 137 fungal asthma deaths annually. We have estimated 445 cases of candidemia a year applying a low European rate. There are approximately 283 cases of invasive aspergillosis annually. There are 189,662 (2.1% of the population) people suffering from serious fungal infections in Tajikistan. Hence, improving diagnostics is the first step of understanding a scale of the fungal burden.

The Burden of Serious Fungal Infections in Kyrgyzstan

Kyrgyzstan in Central Asia has a population of 6 million people who have high mortality rates for chronic lung diseases. The mountainous geography, widespread use of biomass fuels for cooking and indoor heating, and high rates of smoking are the major contributing factors. We have estimated the number of serious fungal infections in order to define the burden of these diseases in Kyrgyzstan. We estimated 774 cases of chronic pulmonary aspergillosis (CPA) as a sequel of tuberculosis (TB); CPA occurs as a sequel of multiple conditions, so a total prevalence of 3097 cases was estimated, which is among the highest rates in the world. An estimated 2205 patients have allergic bronchopulmonary aspergillosis (ABPA) and 2911 have severe asthma with fungal sensitization (SAFS), which may be an underestimate. There are approximately 292 cases of invasive aspergillosis annually. The number of adult women who get recurrent vulvovaginal candidiasis is 175,949. We approximated 787 cases of oral and 294 cases of esophageal candidiasis, 25 cases of cryptococcal meningitis, and 101 cases of Pneumocystis pneumonia annually in HIV-positive patients. The incidence of candidemia was estimated at 300. We have estimated that a total of 185,961 people (3% of the population) have serious fungal infection in Kyrgyzstan. Given this burden, diagnostic improvements are necessary.

Facilitators of adaptation and antifungal resistance mechanisms in clinically relevant fungi

Opportunistic fungal pathogens can cause a diverse range of diseases in humans. The increasing rate of fungal infections caused by strains that are resistant to commonly used antifungals results in difficulty to treat diseases, with accompanying high mortality rates. Existing and newly emerging molecular resistance mechanisms rapidly spread in fungal populations and need to be monitored. Fungi exhibit a diversity of mechanisms to maintain physiological resilience and create genetic variation; processes which eventually lead to the selection and spread of resistant fungal pathogens. To prevent and anticipate this dispersion, the role of evolutionary factors that drive fungal adaptation should be investigated. In this review, we provide an overview of resistance mechanisms against commonly used antifungal compounds in the clinic and for which fungal resistance has been reported. Furthermore, we aim to summarize and elucidate potent generators of genetic variability across the fungal kingdom that aid adaptation to stressful environments. This knowledge can lead to recognizing potential niches that facilitate fast resistance development and can provide leads for new management strategies to battle the emerging resistant populations in the clinic and the environment.

[Allergic respiratory diseases related to mould in the home]

Exposure to mould is a potential risk factor for asthma in both adults and children. In adult, the relation between exposure, sensitization and symptoms has been demonstrated in severe asthmatics sensitized to Alternaria. For children, exposure to mould in childhood is a risk factor for asthma in both atopic and non-atopic individuals. Exposure or sensitization to moulds are a risk factor for severe asthma and/or exacerbations in children. There appears to be a causal relationship between exposure and asthma. This link seems less significant in adults. However, in adults mould sensitive asthma seems to determine a phenotype of severe asthma associated with more marked obstructive lung disease. Moulds can stimulate either innate or the acquired immunity. They are responsible for a marked Th2 inflammation leading to more severe asthma. Besides the immunological mechanisms, toxic mechanisms can also intervene. It is therefore not correct to reduce the effect of moulds, particularly in respiratory symptoms, to only allergic mechanisms.

Early Interaction of Alternaria infectoria Conidia with Macrophages

Fungi of the genus Alternaria are ubiquitous indoor and outdoor airborne agents, and individuals are daily exposed to their spores. Although its importance in human infections and, particularly in respiratory allergies, there are no studies of how Alternaria spp. spores interact with host cells. Our aim was to study the early interaction of Alternaria infectoria spores with macrophages, the first line of immune defense. RAW 264.7 macrophages were infected with A. infectoria conidia, and the internalization and viability of conidia once inside the macrophages were quantified during the first 6 h of interaction. Live cell imaging was used to study the dynamics of this interaction. TNF-α production was quantified by relative gene expression, and the concentration of other cytokines (IL-1α, IL-1β, IL-6, IL-4, IL-10, IL-17, GM-CSF and INF-γ) and a chemokine, MIP-1α, was quantified by ELISA. Conidia were rapidly internalized by macrophages, with approximately half internalized after 30 min of interaction. During the first 6 h of interaction, macrophages retained the ability to mitotically divide while containing internalized conidia. The classical macrophage-activated morphology was absent in macrophages infected with conidia, and TNF-α and other cytokines and chemokines failed to be produced. Thus, macrophages are able to efficiently phagocyte A. infectoria conidia, but, during the first 6 h, no effective antifungal response is triggered, therefore promoting the residence of these fungal conidia inside the macrophages.

Endothelin-1 mediates Aspergillus fumigatus-induced airway inflammation and remodelling

BACKGROUND

Asthma is a chronic inflammatory condition of the airways and patients sensitized to airborne fungi such as Aspergillus fumigatus have more severe asthma. Thickening of the bronchial subepithelial layer is a contributing factor to asthma severity for which no current treatment exists. Airway epithelium acts as an initial defence barrier to inhaled spores, orchestrating an inflammatory response and contributing to subepithelial fibrosis.

OBJECTIVE

We aimed to analyse the production of pro-fibrogenic factors by airway epithelium in response to A fumigatus, in order to propose novel anti-fibrotic strategies for fungal-induced asthma.

METHODS

We assessed the induction of key pro-fibrogenic factors, TGF-β1, TGF-β2, periostin and endothelin-1, by human airway epithelial cells and in mice exposed to A fumigatus spores or secreted fungal factors.

RESULTS

Aspergillus fumigatus specifically caused production of endothelin-1 by epithelial cells in vitro but not any of the other pro-fibrogenic factors assessed. A fumigatus also induced endothelin-1 in murine lungs, associated with extensive inflammation and airway remodelling. Using a selective endothelin-1 receptor antagonist, we demonstrated for the first time that endothelin-1 drives many features of airway remodelling and inflammation elicited by A fumigatus.

CONCLUSION

Our findings are consistent with the hypothesis that elevated endothelin-1 levels contribute to subepithelial thickening and highlight this factor as a possible therapeutic target for difficult-to-treat fungal-induced asthma.

Effects of air pollution on moderate and severe asthma exacerbations

Background: Few studies have evaluated the impact of air pollution levels on the severity of exacerbations. Thus, we compared the relative risks posed by air pollutant levels on moderate and severe exacerbations.Methods: Exacerbation episodes of 618 from 143 adult asthmatics were retrospectively collected between 2005 and 2015 in a tertiary hospital of Korea. Air pollution GPS data for the location closest to each patient's home were obtained from the national ambient monitoring station. The relative impacts of air pollutants on asthma exacerbations were evaluated via a time-trend controlled symmetrical, bidirectional, case-crossover design using conditional logistic regression models on the day of the exacerbation (T-0) and up to 3 days before the exacerbation (T-1-T-3).Results: Overall asthma exacerbation were associated with O₃ levels in summer and winter (OR: 1.012[1.003-1.02] and 1.009[1.003-1.016]), SO₂ levels in spring and summer (OR: 1.009[1-1.018] and 1.02[1.006-1.035]) and NO₂ levels in winter (OR: 1.007[1.003-1.011]). Analyses of the temporal relationship between O₃ concentrations and exacerbations demonstrated that 63.2% of episodes in the summer occurred when the O₃ concentrations on T-1 were significantly higher than those on control days, while 51% of exacerbation episodes in the winter occurred. Severe and moderate exacerbations were similarly associated with O₃ levels in winter (OR: 1.012 [1.003-1.02] vs. 1.01 [0.999-1.021], p > 0.05) and in summer (OR: 1.006 [1.002-1.009] vs. 1.009 [1.003-1.016], p > 0.05).Conclusions: Asthma exacerbations may be associated with the seasonal elevation of O₃, SO₂ and NO₂ levels in summer and winter with the similar relative risk between moderate and severe exacerbations.

Pro-inflammatory responses induced by A. fumigatus and A. versicolor in various human macrophage models

Exposure to mold-contaminated indoor air has been associated with various respiratory diseases, and there is a need for experimental data to confirm these associations. The pro-inflammatory properties of well-characterized aerosolized spores and hyphal fragments from Aspergillus fumigatus and Aspergillus versicolor were examined and compared using various human macrophage cell models including phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages (THP-1 Ma), primary peripheral blood monocyte-derived macrophages (MDM), and primary airway macrophages (AM) from induced sputum. X-ray treated samples of the two mold species induced different responses with A. fumigatus displaying the most potent induction of pro-inflammatory responses. While hyphal fragments from A. fumigatus were more potent than spores, similar responses were produced by the two growth stages of A. versicolor. THP-1 Ma was the most sensitive model releasing a broad range of cytokines/chemokines. MDM exhibited a similar cytokine/chemokine profile as THP-1 Ma, except for a low-quantity release of interleukin-1β (IL-1β). In contrast, AM appeared to be nonresponsive and yielded a different pattern of pro-inflammatory markers. Toll-like receptor (TLR)4, but also to a certain degree TLR2, was involved in several responses induced by spores and aerosolized hyphal fragments of A. fumigatus in MDM. Taken together, MDM seems to be the most promising experimental macrophage model. Abbreviations: AF: A. fumigatus, Aspergillus fumigatus; AV: A. versicolor, Aspergillus versicolor; AM: Airway Macrophage; CBA: Cytometric Bead Array; CD: Cluster of Differentiation; DTT: dithiothreitol; ELISA: Enzyme Linked Immunosorbent Assay; FBS: fetal bovine serum; GM-CSF: Granulocyte macrophage colony-stimulating factor; IL-1β: Interleukin-1beta; MDM: Monocyte-Derived Macrophages; NF-κB: Nuclear Factor kappa light chain enhancer of activated B cells; NLR: NOD-like Receptor; PAMP: Pathogen Associated Molecular Pattern; PMA: Phorbol 12-myristate 13-acetate; PRR: Pattern Recognition Receptor; THP-1: Human leukemia monocyte cell line; TLR: Toll-like Receptor; TNF-α: Tumor Necrosis Factor- alpha.

Burden of fungal asthma in Africa: A systematic review and meta-analysis

BACKGROUND

Asthma is one of the neglected diseases in Africa with a high prevalence. Allergic fungal diseases have been reported to complicate asthma progression and treatment outcomes. However, data about fungal asthma and its associated complications are limited in Africa. We aimed to estimate the burden of fungal asthma among adults and children in Africa using a systematic review.

METHODS

We first engaged the Institute for Health Metrics and Evaluation (IHME) to highlight the trend in morbidity and mortality attributed to asthma in Africa. We then searched PubMed, HINARI and Google Scholar for all studies of any design focusing on fungal asthma in any African country. Languages were restricted to English and French, but not year of publication. We estimated the weighted prevalence of allergic fungal infections among asthmatics with a 95% CI and pooled the results using a random effects model. This study is registered with PROSPERO, number CRD42019117319.

RESULTS

The IHME data showed that there has been a gradual increase in morbidity and mortality due to asthma in African adults with a prevalence of 4%. Our search retrieved 5233 citations. We retained 20 studies that met our selection criteria. These were from 13 African countries published between 1967 and 2018. There were eight cross-sectional studies and twelve review articles. The average asthma prevalence in Africa was 6% from these studies. The prevalence of fungal sensitisation was relatively high (3-52%) in the asthmatic population with an average of 28% and a pooled estimate of 23.3%, mostly due to Aspergillus species. Prevalence of Allergic bronchopulmonary apsergillosis was estimated at 1.6-21.2%. Diagnosis of fungal allergy was mostly made by skin prick tests. There was no data on the use of medication to manage fungal asthma. None of the studies evaluated the association between fungal allergy and asthma severity. Data were lacking in children.

CONCLUSION

There is a high prevalence of fungal sensitization among Africans with asthma. Fungal asthma is a significant problem in Africa but there remains a paucity of data on the epidemiology and associated complications. There is urgent need for national epidemiological studies to estimate the actual burden of fungal asthma in Africa.

Estimated Burden of Serious Fungal Infections in Ghana

Fungal infections are increasingly becoming common and yet often neglected in developing countries. Information on the burden of these infections is important for improved patient outcomes. The burden of serious fungal infections in Ghana is unknown. We aimed to estimate this burden. Using local, regional, or global data and estimates of population and at-risk groups, deterministic modelling was employed to estimate national incidence or prevalence. Our study revealed that about 4% of Ghanaians suffer from serious fungal infections yearly, with over 35,000 affected by life-threatening invasive fungal infections. Incidence of cryptococcal meningitis, Pneumocystis jirovecii pneumonia, and disseminated histoplasmosis cases in AIDS was estimated at 6275, 12,610 and 724, respectively. Oral and esophageal candidiasis collectively affect 27,100 Ghanaians and 42,653 adult asthmatics are estimated to have fungal asthma. We estimate a prevalence of 12,620 cases of chronic pulmonary aspergillosis (CPA and an incidence of 1254 cases of invasive aspergillosis (IA). Estimated cases of candidemia and candida peritonitis cases were 1446 and 217, respectively. The estimated prevalence of recurrent vulvovaginal candidiasis (RVVC) and tinea capitis was 442,621 and 598,840, respectively. Mucormycosis and fungal keratitis each may affect 58 and 810 Ghanaians. These data highlight the urgent need for intensified awareness to improve diagnosis and management.

Regulation of IL-17A and implications for TGF-β1 comodulation of airway smooth muscle remodeling in severe asthma

Severe asthma develops as a result of heightened, persistent symptoms that generally coincide with pronounced neutrophilic airway inflammation. In individuals with severe asthma, symptoms are poorly controlled by high-dose inhaled glucocorticoids and often lead to elevated morbidity and mortality rates that underscore the necessity for novel drug target identification that overcomes limitations in disease management. Many incidences of severe asthma are mechanistically associated with T helper 17 (TH17) cell-derived cytokines and immune factors that mediate neutrophilic influx to the airways. TH17-secreted interleukin-17A (IL-17A) is an independent risk factor for severe asthma that impacts airway smooth muscle (ASM) remodeling. TH17-derived cytokines and diverse immune mediators further interact with structural cells of the airway to induce pathophysiological processes that impact ASM functionality. Transforming growth factor-β1 (TGF-β1) is a pivotal mediator involved in airway remodeling that correlates with enhanced TH17 activity in individuals with severe asthma and is essential to TH17 differentiation and IL-17A production. IL-17A can also reciprocally enhance activation of TGF-β1 signaling pathways, whereas combined TH1/TH17 or TH2/TH17 immune responses may additively impact asthma severity. This review seeks to provide a comprehensive summary of cytokine-driven T cell fate determination and TH17-mediated airway inflammation. It will further review the evidence demonstrating the extent to which IL-17A interacts with various immune factors, specifically TGF-β1, to contribute to ASM remodeling and altered function in TH17-driven endotypes of severe asthma.

The antifungal activity of extracts of Osmundea pinnatifida, an edible seaweed, indicates its usage as a safe environmental fungicide or as a food additive preventing post-harvest fungal food contamination

In the present work, we explored the antifungal activity of the wild edible seaweed Osmundea pinnatifida (Rhodophyta) collected from the Portuguese coast, which is used as a food seasoning in Scotland, Ireland and Portugal. We performed a sequential extraction of the seaweed components with methanol, dichloromethane and n-hexane. These extracts showed an antifungal activity against Alternaria infectoria and Aspergillus fumigatus. The n-hexane fraction of the seaweed inhibited the sporulation of Alternaria infectoria at 30 μg mL-1 and induced a statistically significant (P < 0.001) decrease in β-glucan content. Furthermore, liquid cultures of Aspergillus fumigatus supplemented with 10 μg mL-1 of the n-hexane fraction showed abnormal conidiophores, completely devoid of phialides and conidia associated with a decrease of 18.3% in the chitin content (P < 0.01). The n-hexane fraction analysis by GC-MS revealed that it includes palmitic acid (29.6%), phytol isomer 1 (12.8%), oleic acid (9.6%), stearic acid (6.2%) and d-(-)-tagatofuranose (4.1%), among other compounds present at lower concentrations. The present study reveals Osmundea pinnatifida as a promising source of biologically active compounds inhibiting fungal growth and conidiation, the main dispersal mechanism of filamentous fungi as Aspergillus fumigatus and Alternaria alternata, revealing its utility both as an environmental fungicide against fungal diseases and as a food preservative against fungal post-harvest food contamination.

Prevalence of sensitization to Aspergillus flavus in patients with allergic bronchopulmonary aspergillosis

Aspergillus fumigatus is the most common Aspergillus species worldwide; however, A. flavus has also been shown to be prevalent in North India. Herein, we investigate the prevalence of sensitization to A. flavus in subjects with allergic bronchopulmonary aspergillosis (ABPA). We also evaluate the occurrence of allergic bronchopulmonary mycosis (ABPM) due to A. flavus. Treatment-naive subjects with ABPA underwent sputum culture; and, skin testing, fungal-specific immunoglobulin E (IgE) and serum precipitation tests for A. fumigatus and A. flavus. Sensitization to A. flavus was diagnosed if any immunological test for A. flavus was positive in subjects with ABPA. ABPM was labelled as probable if sputum cultures grew A. flavus and A. flavus-specific IgE was greater than A. fumigatus-specific IgE; and, possible if only A. flavus-specific IgE was greater than A. fumigatus-specific IgE. Fifty-three subjects with a mean (SD) age of 34.2 (12.8) years were included. Sensitization to A. flavus was seen in 51 (96.2%) subjects, with overlap occurring in 49 (92.5%), 21 (39.6%), and 12 (22.6%) instances on fungal-specific IgE, skin prick test and precipitins, respectively. Sputum culture was positive in 18 (33.9%; A. flavus [n = 12], A. fumigatus [n = 6]) subjects. ABPM due to A. flavus was diagnosed in 16 (30.2%) subjects (10 probable, 6 possible). They were more likely to have high-attenuation mucus and a trend towards higher occurrence of sinusitis, compared to ABPA. We found a high occurrence of sensitization to A. flavus in subjects with ABPA. Subjects with A. flavus-related ABPM had a higher likelihood of high-attenuation mucus and probability of sinusitis. More studies are required to confirm this observation.

Pathophysiological aspects of Aspergillus colonization in disease

Aspergillus colonization of the lower respiratory airways is common in normal people, and of little clinical significance. However, in some patients, colonization is associated with severe disease including poorly controlled asthma, allergic bronchopulmonary aspergillosis (ABPA) with sputum plugs, worse lung function in chronic obstructive pulmonary aspergillosis (COPD), invasive aspergillosis, and active infection in patients with chronic pulmonary aspergillosis (CPA). Therefore, understanding the pathophysiological mechanisms of fungal colonization in disease is essential to develop strategies to avert or minimise disease. Aspergillus cell components promoting fungal adherence to the host surface, extracellular matrix, or basal lamina are indispensable for pathogen persistence. However, our understanding of individual differences in clearance of A. fumigatus from the lung in susceptible patients is close to zero.

Challenging cases in fungal asthma

Fungal asthma broadly encompasses the presence of fungal sensitization or fungal allergy in patients with asthma. The clinical presentation of fungal asthma can vary from fungal-sensitized asthma at one end to allergic bronchopulmonary mycosis at the other end of the spectrum. Here we present five cases that illustrate some of the most challenging aspects of the diagnosis and management of fungal asthma. The cases are aimed at elucidating complex clinical presentations in fungal asthma such as allergic bronchopulmonary mycosis presenting with normal immunoglobulin E (IgE) values, the role of several different fungi in causing allergic mycosis, newer treatments like omalizumab (and mepolizumab), and a complication of long-standing allergic bronchopulmonary aspergillosis, namely, chronic pulmonary aspergillosis.

Comparing the profile of respiratory fungal pathogens amongst immunocompetent and immunocompromised hosts, their susceptibility pattern and correlation of various opportunistic respiratory fungal infections and their progression in relation to the CD4+T-cell counts

Introduction

Invasive fungal infections are increasingly common in the nosocomial setting.

Materials and Methods

The patients were divided into two groups immunocompetent and immunocompromised that is, patients with significant neutropenia <500 neutrophils/μl for longer than 10 days. microscopy, culture, identification of isolates were done and some specilised tests on serum and BAL for antigen detection were performed.

Results

Majority of the patients were young adult males in this study. A higher prevalence of 26.7% was seen in immunocompromised patients. Amongst yeasts, Candida albicans was the predominant species followed by the National AIDS Control that is, Candida glabrata, Candida dubliniensis, Candida parapsilosis and Candida tropicalis in the same order. Amongst moulds, Aspergillus fumigatus was the most common species followed by Aspergillus flavus and Aspergillus niger. Mucor and Penicillium marneffei were seen in a lower prevalence. By Broth microdilution method, isolates of Candida spp. were most sensitive to caspofungin, amphotericin B, ketoconazole and fluconazole in the same order. Isolates of Aspergillus spp. were most sensitive to caspofungin, amphotericin B and itraconazole in the same order. By disc diffusion method, resistance to fluconazole was observed in 6.9% isolates of C. albicans. 50% of C. dubliniensis and 20% of C. glabrata showed resistance to fluconazole. A total mortality of 27.7% was observed during this study. This was distributed as 24.1%, 26.7%, 50%, 50%, 100% and 0% among by patients of candidiasis, aspergillosis, cryptococcosis, pneumocystosis, mucormycosis and penicilliosis. Fifteen per cent were lost to follow-up.

Conclusion

Patterns of invasive fungal infections are changing in many ways. In the midst of these evolving trends, IFI of the respiratory tractcontinue to remain important causes of morbidity and mortality. Diagnostic tools can be adequately used only if the treating physician is aware of the propensity of patients to acquire a fungal infection. Thus, continuous awareness and education is crucial for successful management of patients. Judicious use of antifungal medications as prophylactic measures must be employed, particularly in the critically ill and patients of HIV.

Prevalence of specific immunoglobulin E and G against Aspergillus fumigatus in patients with asthma

Background and Purpose

Aspergillus fumigatus as a ubiquitous fungus can be found in the respiratory tract of the asthmatic and healthy people. The inhalation of Aspergillus spores leads to an immune response in individuals with asthma and results in the aggravation of the clinical symptoms. The present study aimed to investigate the prevalence of specific immunoglobulin E and G (IgE and IgG) against A.fumigatus in asthmatic patients.

Materials and Methods

This study was conducted on 200 consecutive patients with moderate to severe asthma referring to Masih Daneshvari hospital Tehran, Iran, from January 2016 to February 2018. Skin prick test (SPT) was performed in all subjects with Aspergillus allergens. Moreover, all patients underwent specific IgE testing for Aspergillus using Hycor method. Enzyme immune assay was applied to measure total IgE and Aspergillus-specific IgG.

Results

According to the results, the mean age of the patients was 45.8 years (age range: 18-78 years). The mean levels of total IgE and Aspergillus specific IgE in asthmatic patients were obtained as 316.3 (range: 6-1300 IU/ml) and 1.5 (range: 0.1-61.3 IU/ml), respectively. Out of 200 patients, 27 (13.5%), 65 (32.5%), 22 (11.0%), and 86 (43.0%) cases had positive Aspergillus SPT, total IgE of > 417 IU/ml, Aspergillus -specific IgE, and IgG, respectively. The level of these variables in patients with severe asthma were 16 (16.5%), 36 (37.1%), 15 (15.5%), and 46 (47.4%), respectively.

Conclusion

As the findings indicated, reactivity to Aspergillus is a remarkable phenomenon in asthmatic patients. It is also emphasised that the climatic condition may affect the positive rate of hypersensitivity to Aspergillus.

Severe Asthma and Allergy: A Pediatric Perspective

Severe asthma in children is associated with significant morbidity and lung function decline. It represents a highly heterogeneous disorder with multiple clinical phenotypes. As its management is demanding, the social and economic burden are impressive. Several co-morbidities may contribute to worsen asthma control and complicate diagnostic and therapeutic management of severe asthmatic patients. Allergen sensitization and/or allergy symptoms may predict asthma onset and severity. A better framing of "allergen sensitization" and understanding of mechanisms underlying progression of atopic march could improve the management and the long-term outcomes of pediatric severe asthma. This review focuses on the current knowledge about interactions between severe asthma and allergies.

Fungi in respiratory samples of horses with inflammatory airway disease

Background

Fungi contribute to the inflammatory response of lungs in horses with recurrent airway obstruction and in some forms of asthma in humans. The role of fungi in inflammatory airway disease (IAD) has not been assessed.

Objectives

Evaluate the prevalence of fungi in the respiratory samples of horses diagnosed with IAD, describe clinical signs associated with the presence of fungi in respiratory samples, and assess the risk factors associated with IAD and with the presence of fungi in the airways.

Animals

Seven‐hundred thirty‐one active horses referred to a specialized ambulatory practice for signs of respiratory disease or poor performance.

Methods

A prospective observational study was performed, collecting clinical data, environmental conditions, and results of a tracheal wash (TW; cytology, fungal culture, and bacterial culture), and bronchoalveolar lavage (cytology).

Results

A positive fungal culture was obtained in 55% (402/731) of horses. Horses with fungal elements observed on the TW cytology had 2 times greater chance of having IAD than horses without fungi (odds ratio [OR] = 2.1; 95% CI 1.08‐3.33; P = .0003). Risks of being diagnosed with IAD and likelihood of fungi in TW were higher when horses were bedded on straw (OR = 2.0; 95% CI 1.2‐3.2 and OR = 1.9; 95% CI 1.3‐2.6, respectively) or fed dry hay (OR = 2.7; 95% CI 1.7‐4.4 and OR = 2.6; 95% CI 1.6‐3.4, respectively).

Conclusions and Clinical Importance

Horses inhaling aerosolized fungal particles are at a significantly higher risk of developing IAD. The type of bedding and forage represent significant risk factors for IAD and fungal contamination of equine airways.

IL-33, IL-25 and TSLP contribute to development of fungal-associated protease-induced innate-type airway inflammation

Certain proteases derived from house dust mites and plants are considered to trigger initiation of allergic airway inflammation by disrupting tight junctions between epithelial cells. It is known that inhalation of proteases such as house dust mite-derived Der p1 and/or papaya-derived papain caused airway eosinophilia in naïve mice and even in Rag-deficient mice that lack acquired immune cells such as T, B and NKT cells. In contrast, little is known regarding the possible involvement of proteases derived from Aspergillus species (fungal-associated proteases; FAP), which are ubiquitous saprophytic fungi in the environment, in the development of allergic airway eosinophilia. Here, we found that inhalation of FAP by naïve mice led to airway eosinophilia that was dependent on protease-activated receptor-2 (PAR2), but not TLR2 and TLR4. Those findings suggest that the protease activity of FAP, but not endotoxins in FAP, are important in the setting. In addition, development of that eosinophilia was mediated by innate immune cells (ILCs) such as innate lymphoid cells, but not by acquired immune cells such as T, B and NKT cells. Whereas IL-33, IL-25 and thymic stromal lymphopoietin (TSLP) are involved in induction of FAP-induced ILC-mediated airway eosinophilia, IL-33-rather than IL-25 and/or TSLP-was critical for the eosinophilia in our model. Our findings improve our understanding of the molecular mechanisms involved in induction of airway inflammation by FAP.

Fungal Diseases in the 21st Century: The Near and Far Horizons

Fungal diseases became a major medical problem in the second half of the 20th century when advances in modern medicine together with the HIV epidemic resulted in large numbers of individuals with impaired immunity. Fungal diseases are difficult to manage because they tend to be chronic, hard to diagnose, and difficult to eradicate with antifungal drugs. This essay considers the future of medical mycology in the 21st century, extrapolating from current trends. In the near horizon, the prevalence of fungal diseases is likely to increase, as there will be more hosts with impaired immunity and drug resistance will inevitably increase after selection by antifungal drug use. We can expect progress in the development of new drugs, diagnostics, vaccines, and immunotherapies. In the far horizon, humanity may face new fungal diseases in association with climate change. Some current associations between chronic diseases and fungal infections could lead to the establishment of fungi as causative agents, which will greatly enhance their medical importance. All trends suggest that the importance of fungal diseases will increase in the 21st century, and enhanced human preparedness for this scourge will require more research investment in this group of infectious diseases.

Lung colonization by Aspergillus fumigatus is controlled by ZNF77

Aspergillus fumigatus is a critical pathogen of humans. Exposure to A. fumigatus conidia occurs frequently but is normally cleared from the respiratory airways. In contrast, individuals with respiratory diseases are often highly colonized by fungi. Here, we use genome-edited epithelial cells to show that the genetic variant rs35699176 in ZNF77 causes loss of integrity of the bronchial epithelium and increases levels of extracellular matrix proteins. These changes promote A. fumigatus conidial adhesion, germination and growth. RNA-seq and LC/MS-MS analysis reveal rs35699176 upregulates vesicle trafficking leading to an increment of adhesion proteins. These changes make cells carrying rs35699176 more receptive to A. fumigatus in the early stages of infection. Moreover, patients with fungal asthma carrying rs35699176^+/- have higher A. fumigatus loads in their respiratory airway. Our results indicate ZNF77 as a key controller of Aspergillus colonization and suggest its utility as a risk-marker for patient stratification.

Evaluation of Aspergillus and Mucorales specific T-cells and peripheral blood mononuclear cell cytokine signatures as biomarkers of environmental mold exposure

Mold specific T-cells have been described as a supportive biomarker to monitor invasive mycoses and mold exposure. This study comparatively evaluated frequencies and cytokine profiles of Aspergillus fumigatus and Mucorales reactive T-cells depending on environmental mold exposure. Peripheral blood mononuclear cells (PBMCs) obtained from 35 healthy donors were stimulated with mycelial lysates of A. fumigatus and three human pathogenic Mucorales species. CD154⁺ specific T-cells were quantified by flow cytometry. In a second cohort of 20 additional donors, flow cytometry was complemented by 13-plex cytokine assays. Mold exposure of the subjects was determined using a previously established questionnaire. Highly exposed subjects exhibited significantly greater CD154⁺A. fumigatus and Mucorales specific naïve and memory T-helper cell frequencies. Significant correlation (r = 0.48 - 0.79) was found between A. fumigatus and Mucorales specific T-cell numbers. Logistic regression analyses revealed that combined analysis of mold specific T-cell frequencies and selected cytokine markers (A. fumigatus: IL-5 and TNF-α, R. arrhizus: IL-17A and IL-13) significantly improves classification performance, resulting in 75-90 % predictive power using 10-fold cross-validation. In conclusion, mold specific T-cell frequencies and their cytokine signatures offer promising potential in the assessment of environmental mold exposure. The cytokines identified in this pilot study should be validated in the clinical setting, e. g. in patients with hypersensitivity pneumonitis.

The common γ-chain cytokine IL-7 promotes immunopathogenesis during fungal asthma

Asthmatics sensitized to fungi are reported to have more severe asthma, yet the immunopathogenic pathways contributing to this severity have not been identified. In a pilot assessment of human asthmatics, those subjects sensitized to fungi demonstrated elevated levels of the common γ-chain cytokine IL-7 in lung lavage fluid, which negatively correlated with the lung function measurement PC20. Subsequently, we show that IL-7 administration during experimental fungal asthma worsened lung function and increased the levels of type 2 cytokines (IL-4, IL-5, IL-13), proallergic chemokines (CCL17, CCL22) and proinflammatory cytokines (IL-1α, IL-1β). Intriguingly, IL-7 administration also increased IL-22, which we have previously reported to drive immunopathogenic responses in experimental fungal asthma. Employing IL22CreR26ReYFP reporter mice, we identified γδ T cells, iNKT cells, CD4 T cells and ILC3s as sources of IL-22 during fungal asthma; however, only iNKT cells were significantly increased after IL-7 administration. IL-7-induced immunopathogenesis required both type 2 and IL-22 responses. Blockade of IL-7Rα in vivo resulted in attenuated IL-22 production, lower CCL22 levels, decreased iNKT cell, CD4 T-cell and eosinophil recruitment, yet paradoxically increased dynamic lung resistance. Collectively, these results suggest a complex role for IL-7 signaling in allergic fungal asthma.

Relationship between mold exposure, specific IgE sensitization, and clinical asthma: A case-control study

BACKGROUND

Most of the findings related to the noxious effect of mold sensitization on asthma come from investigations based on Alternaria alternata, Cladosporium herbarum, and Aspergillus fumigatus. However, species such as Penicillium spp, Cladosporium sphaerospermum, Cladosporium cladosporioides, or Aspergillus versicolor display a more pronounced indoor tropism, and their potential harmful respiratory effects cannot be neglected.

OBJECTIVE

The goal of this work was to relate mold sensitizations with asthma severity and with the level of indoor mold contamination among mold-sensitized patients with asthma and nonsensitized patients with asthma.

METHODS

A case-control study was conducted and several asthma severity markers were compared between patients with asthma with and without mold sensitization. Indoor contamination of patients' dwellings was also investigated.

RESULTS

Our findings confirmed the association between sensitization to A fumigatus and severity for patients with asthma in contrast with sensitization to other species. Indoor mold contamination was detected in approximately 90% of dwellings. Overall mold exposure was not associated with asthma severity. However, regardless of the sensitization, exposure to A fumigatus and Penicillium spp in dust was linked to an increased risk of severe asthma.

CONCLUSION

The harmful nature of mold sensitization and mold exposure for patients with asthma was not confirmed in this study. However, sensitization to A fumigatus was associated with an increased risk for severe asthma. A better investigation of the properties of Penicillium spp is recommended because its exposure was found to be associated with a more pronounced impairment of lung function.

Estimated Burden of Serious Fungal Infections in Malawi

Despite efforts to address the burden of fungal infections in Malawi, the prevalence and incidence remain largely unknown. We assessed the annual burden in the general population and among populations at high risk and fungal infection frequencies in each particular population to estimate the national incidence or prevalence. The Malawi population is approximately 17.7 million (2017), with 48% under 15 years of age. Approximately 8% of the population is HIV positive. The most common infections are present in HIV/AIDS patients, with oral candidiasis being the commonest. Life threatening infections among those with AIDS patients include cryptococcal meningitis (8200 cases) and Pneumocystis pneumonia (3690 cases). Pulmonary TB is common, but extra pulmonary TB is rare; an estimated 2329 people have chronic pulmonary aspergillosis after TB. Asthma is a significant problem in Malawi, with an estimated 680,000 adults affected (4.67%) and 14,010 cases of allergic bronchopulmonary aspergillosis (ABPA). Tinea capitis is estimated to be present in over 670,000 young people (21% of school age children). The annual incidence of fungal keratitis is difficult to estimate, but as cases are frequently seen in the eye department, is likely to be a minimum of 1825 (10.3/100,000) cases. Among the most serious infections, cryptococcal meningitis and Pneumocystis pneumonia are top of the list. Overall, some 1,338,523 (7.54%) people are affected by a serious fungal infection in Malawi. These basic estimates are limited, due to poor record keeping, and require epidemiological studies to validate or modify the substantial burden estimates. National surveillance of fungal infections is urgently needed.

Burden of Serious Fungal Infections in Argentina

The number of fungal infections at any given time in Argentina is not known. Here we estimate the burden of serious fungal infections in Argentina for the first time. Specific population statistics were searched from multiple sources, local literature was identified, and estimates made. Some additional data were sourced from the Ministry of Health, the Global Initiative for Asthma (GINA) program, and national haematology and transplant societies. Argentina has a population of 43.8 million, with 25% of this total being children under 15 years. The predicted candidemia annual incidence is 2193 cases, with 50% occurring in the ICU. At a 6% prevalence rate, an estimated 593,695 women suffer from recurrent vulvovaginal candidiasis. Invasive aspergillosis is relatively common because of high smoking and chronic obstructive pulmonary disease (COPD) rates, with 268 cases in immunocompromised patients and another 1938 in the 168,000 COPD patients admitted to hospital. Asthma is also common, affecting 14% of adults, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) are major problems. An estimated 432 cases of cryptococcal meningitis (CM)—90% of them in AIDS patients—and 1177 cases of Pneumocystis pneumonia (PCP) occur each year. The estimated annual case number of disseminated histoplasmosis is 404 in AIDS patients, almost as frequent as CM. Paracoccidioidomycosis annual incidence is estimated at 219, and coccidioidomycosis at 16 cases. At least 881,023 people (>2.01%) in Argentina are affected by a serious fungal disease annually, with considerable morbidity and mortality.

Airway epithelial phosphoinositide 3-kinase-δ contributes to the modulation of fungi-induced innate immune response

Background

Respiratory fungal exposure is known to be associated with severe allergic lung inflammation. Airway epithelium is an essential controller of allergic inflammation. An innate immune recognition receptor, nucleotide-binding domain, leucine-rich-containing family, pyrin-domain-containing-3 (NLRP3) inflammasome, and phosphoinositide 3 kinase (PI3K)-δ in airway epithelium are involved in various inflammatory processes.

Objectives

We investigated the role of NLRP3 inflammasome in fungi-induced allergic lung inflammation and examined the regulatory mechanism of NLRP3 inflammasome, focusing on PI3K-δ in airway epithelium.

Methods

We used two in vivo models induced by exposure to Aspergillus fumigatus (Af) and Alternaria alternata (Aa), as well as an Af-exposed in vitro system. We also checked NLRP3 expression in lung tissues from patients with allergic bronchopulmonary aspergillosis (ABPA).

Results

Assembly/activation of NLRP3 inflammasome was increased in the lung of Af-exposed mice. Elevation of NLRP3 inflammasome assembly/activation was observed in Af-stimulated murine and human epithelial cells. Similarly, pulmonary expression of NLRP3 in patients with ABPA was increased. Importantly, neutralisation of NLRP3 inflammasome derived IL-1β alleviated pathophysiological features of Af-induced allergic inflammation. Furthermore, PI3K-δ blockade improved Af-induced allergic inflammation through modulation of NLRP3 inflammasome, especially in epithelial cells. This modulatory role of PI3K-δ was mediated through the regulation of mitochondrial reactive oxygen species (mtROS) generation. NLRP3 inflammasome was also implicated in Aa-induced eosinophilic allergic inflammation, which was improved by PI3K-δ blockade.

Conclusion

These findings demonstrate that fungi-induced assembly/activation of NLRP3 inflammasome in airway epithelium may be modulated by PI3K-δ, which is mediated partly through the regulation of mtROS generation. Inhibition of PI3K-δ may have potential for treating fungi-induced severe allergic lung inflammation.

Ginsenoside Rg1 Exhibits Anti-asthmatic Activity in an Aspergillus Protease-Induced Asthma Model in Mice

Asthma is one of the most common chronic airway diseases and is characterized by symptoms, such as, wheezing and coughing. Its prevalence in Korea is gradually increasing among children and adults, especially among those older than 60 years. In this study, we investigated the effects of ginsenoside Rg1 (Rg1), one of the major constituents of Panax ginseng Meyer on ovalbumin (OVA) plus Aspergillus protease ( A. protease) allergen-induced asthmatic mice. Mice were orally administered Rg1 for 10 days from 8 days after OVA + A. protease sensitization and intranasally administered booster doses of OVA + A. protease for 4 days from 14 days after sensitization. The effects of Rg1 administration on airway hyperresponsiveness (AHR), immune cell distributions in bronchoalveolar lavage fluid (BALF), and serum level of immunoglobulin E (IgE) were investigated at 18 days after sensitization. Histopathological changes in hematoxylin and eosin (H&E)-stained lung sections were also examined. Treatment of OVA + A. protease-sensitized/challenged asthmatic mice with Rg1 significantly decreased total eosinophil counts in BALF as compared with those of phosphate-buffered saline (PBS)-treated sensitized/challenged controls, and significantly decreased methacholine-induced AHR. Furthermore, IgE serum levels were significantly lower in Rg1 administered OVA + A. protease-sensitized asthmatic mice than in PBS-treated sensitized/challenged controls. The study shows Rg1 protects against A. protease allergen-induced asthma in mice.

The Burden of Serious Fungal Infections in Cameroon

Fungal infections are frequent in Cameroon, and invasive fungal infections are sometimes detected, usually in HIV-infected patients. For these reasons, we have estimated the burden of fungal infections. Using published literature and population estimates for the at-risk group, we used deterministic modelling to derive national incidence and prevalence estimates for the most serious fungal diseases. HIV infection is common and an estimated 120,000 have CD4 counts <200 × 10⁶/mL and commonly present with opportunistic infection. Oesophageal candidiasis in HIV is common, and in poorly controlled diabetics. We estimate 6720 cases of cryptococcal meningitis, 9000 of Pneumocystis pneumonia, 1800 of disseminated histoplasmosis annually complicating AIDS, and 1200 deaths from invasive aspergillosis in AIDS, but there are no data. We found that 2.4% of adults have chronic obstructive pulmonary disease (COPD) and 2.65% have asthma, with "fungal asthma" affecting 20,000. Chronic pulmonary aspergillosis probably affects about 5000 people, predominantly after tuberculosis but also with COPD and other lung diseases. Also, tinea capitis in schoolchildren is frequent. Overall, an estimated 1,235,775 people are affected by a serious fungal infection. There is an urgent need for government and clinician attention, improved laboratory facilities, fungal diagnostic tests, and competent laboratory technicians, as well as all World Health Organization (WHO)-endorsed essential antifungal drugs to be made available, as only fluconazole is registered and available in the country.

Development of allergic immunity in early life

The growth and maturity of the peripheral immune system and subsequent development of pulmonary immunity in early life is dictated by host, environmental and microbial factors. Dysregulation during the critical window of immune development in the postnatal years results in disease which impacts on lifelong lung health. Asthma is a common disease in childhood and is often preceded by wheezing illnesses during the preschool years. However, the mechanisms underlying development of wheeze and how and why only some children progress to asthma is unknown. Human studies to date have generally focused on peripheral immune development, with little assessment of local tissue pathology in young children. Moreover, mechanisms underlying the interactions between inflammation and tissue repair at mucosal surfaces in early life remain unknown. Disappointingly, mechanistic studies in mice have predominantly used adult models. This review will consider the aspects of the neonatal immune system which might contribute to the development of early life wheezing disorders and asthma, and discuss the external environmental factors which may influence this process.

Estimating the Burden of Serious Fungal Infections in Uruguay

We aimed to estimate for the first time the burden of fungal infections in Uruguay. Data on population characteristics and underlying conditions were extracted from the National Statistics Institute, the World Bank, national registries, and published articles. When no data existed, risk populations were used to estimate frequencies extrapolating from the literature. Population structure (inhabitants): total 3,444,006; 73% adults; 35% women younger than 50 years. Size of populations at risk (total cases per year): HIV infected 12,000; acute myeloid leukemia 126; hematopoietic stem cell transplantation 30; solid organ transplants 134; COPD 272,006; asthma in adults 223,431; cystic fibrosis in adults 48; tuberculosis 613; lung cancer 1400. Annual incidence estimations per 100,000: invasive aspergillosis, 22.4; candidemia, 16.4; Candida peritonitis, 3.7; Pneumocystis jirovecii pneumonia, 1.62; cryptococcosis, 0.75; severe asthma with fungal sensitization, 217; allergic bronchopulmonary aspergillosis, 165; recurrent Candida vaginitis, 6323; oral candidiasis, 74.5; and esophageal candidiasis, 25.7. Although some under and overestimations could have been made, we expect that at least 127,525 people suffer from serious fungal infections each year. Sporothrichosis, histoplasmosis, paracoccidioidomycosis, and dermatophytosis are known to be frequent but no data are available to make accurate estimations. Given the magnitude of the burden of fungal infections in Uruguay, efforts should be made to improve surveillance, strengthen laboratory diagnosis, and warrant access to first line antifungals.

The Mycobiome: A Neglected Component in the Microbiota-Gut-Brain Axis

In recent years, the gut microbiota has been considered as a full-fledged actor of the gut-brain axis, making it possible to take a new step in understanding the pathophysiology of both neurological and psychiatric diseases. However, most of the studies have been devoted to gut bacterial microbiota, forgetting the non-negligible fungal flora. In this review, we expose how the role of the fungal component in the microbiota-gut-brain axis is legitimate, through its interactions with both the host, especially with the immune system, and the gut bacteria. We also discuss published data that already attest to a role of the mycobiome in the microbiota-gut-brain axis, and the impact of fungi on clinical and therapeutic research.

Mold and Human Health: a Reality Check

There are possibly millions of mold species on earth. The vast majority of these mold spores live in harmony with humans, rarely causing disease. The rare species that does cause disease does so by triggering allergies or asthma, or may be involved in hypersensitivity diseases such as allergic bronchopulmonary aspergillosis or allergic fungal sinusitis. Other hypersensitivity diseases include those related to occupational or domiciliary exposures to certain mold species, as in the case of Pigeon Breeder's disease, Farmer's lung, or humidifier fever. The final proven category of fungal diseases is through infection, as in the case of onchomycosis or coccidiomycosis. These diseases can be treated using anti-fungal agents. Molds and fungi can also be particularly important in infections that occur in immunocompromised patients. Systemic candidiasis does not occur unless the individual is immunodeficient. Previous reports of "toxic mold syndrome" or "toxic black mold" have been shown to be no more than media hype and mass hysteria, partly stemming from the misinterpreted concept of the "sick building syndrome." There is no scientific evidence that exposure to visible black mold in apartments and buildings can lead to the vague and subjective symptoms of memory loss, inability to focus, fatigue, and headaches that were reported by people who erroneously believed that they were suffering from "mycotoxicosis." Similarly, a causal relationship between cases of infant pulmonary hemorrhage and exposure to "black mold" has never been proven. Finally, there is no evidence of a link between autoimmune disease and mold exposure.