The effect of outdoor fungal spore concentrations on daily asthma severity

The Impact of Climate Change on the Sporulation of Atmospheric Fungi

The U.S. Global Change Research Program, Fourth National Climate Assessment reports that it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. There are no convincing alternative explanations supported by observational evidence.

Recent progress on phytoremediation of urban air pollution

The rapid growth of population and economy has led to an increase in urban air pollutants, greenhouse gases, energy shortages, environmental degradation, and species extinction, all of which affect ecosystems, biodiversity, and human health. Atmospheric pollution sources are divided into direct and indirect pollutants. Through analysis of the sources of pollutants, the self-functioning of different plants can be utilized to purify the air quality more effectively. Here, we explore the absorption of greenhouse gases and particulate matter in cities as well as the reduction of urban temperatures by plants based on international scientific literature on plant air pollution mitigation, according to the adsorption, dust retention, and transpiration functions of plants. At the same time, it can also reduce the occurrence of extreme weather. It is necessary to select suitable tree species for planting according to different plant functions and environmental needs. In the context of tight urban land use, the combination of vertical greening and urban architecture, through the rational use of plants, has comprehensively addressed urban air pollution. In the future, in urban construction, attention should be paid to the use of heavy plants and the protection and development of green spaces. Our review provides necessary references for future urban planning and research.

Prediction of the number of asthma patients using environmental factors based on deep learning algorithms

BACKGROUND

Air pollution, weather, pollen, and influenza are typical aggravating factors for asthma. Previous studies have identified risk factors using regression-based and ensemble models. However, studies that consider complex relationships and interactions among these factors have yet to be conducted. Although deep learning algorithms can address this problem, further research on modeling and interpreting the results is warranted.

METHODS

In this study, from 2015 to 2019, information about air pollutants, weather conditions, pollen, and influenza were utilized to predict the number of emergency room patients and outpatients with asthma using recurrent neural network, long short-term memory (LSTM), and gated recurrent unit models. The relative importance of the environmental factors in asthma exacerbation was quantified through a feature importance analysis.

RESULTS

We found that LSTM was the best algorithm for modeling patients with asthma. Our results demonstrated that influenza, temperature, PM10, NO2, CO, and pollen had a significant impact on asthma exacerbation. In addition, the week of the year and the number of holidays per week were an important factor to model the seasonality of the number of asthma patients and the effect of holiday clinic closures, respectively.

CONCLUSION

LSTM is an excellent algorithm for modeling complex epidemiological relationships, encompassing nonlinearity, lagged responses, and interactions. Our study findings can guide policymakers in their efforts to understand the environmental factors of asthma exacerbation.

Annual Change in Fungal Concentrations and Allergic Sensitization Rates to Alternaria and Cladosporium in Korea During the Period 1998-2022

PURPOSE

Atmospheric fungi are associated with respiratory allergies in humans, and some fungal spores can cause allergic diseases. Environmental and biological factors influence the concentrations of atmospheric spores. In this study, we evaluated the climate change-induced annual variations in fungal spore concentrations and allergic sensitization rates in the Seoul Metropolitan Area over a period of 25 years.

METHODS

Fungal spores and pollen were obtained from Hanyang University Seoul and Guri Hospitals; they were identified and counted for 25 years (1998-2022). The study participants included patients who underwent tests for allergic diseases in both hospitals. Their allergenic sensitization rates were determined via allergic skin prick and serum tests, after which their sensitization rates to allergenic fungi and pollens were calculated. The daily climatic variables were obtained from the Korea Meteorological Administration.

RESULTS

The total annual atmospheric fungal concentrations decreased in both areas during the period. Simultaneously, we recruited 21,394 patients with allergies (asthma, 1,550; allergic rhinitis, 5,983; and atopic dermatitis, 5,422) from Seoul and Guri Hospitals for allergenic fungal sensitization evaluations over the period. The allergenic fungal sensitization rates decreased annually in both areas over that time `+(Alternaria [3.5%] and Cladosporium [4.4%] in 1998; Alternaria [0.2%] and Cladosporium [0.2%] in 2022). In contrast, the annual pollen concentrations increased with the sensitization rates to pollen in children.

CONCLUSIONS

The atmospheric fungal concentrations decreased annually, with allergic sensitization rate decreasing over the period of 25 years. Allergenic fungal sporulation could decrease with climate changes, such as desertification and drought. Extended monitoring periods and further large-scale studies are required to confirm the causality and to evaluate the impact of climate change.

Impact of Fungal Spores on Asthma Prevalence and Hospitalization

Despite making up a significant proportion of airborne allergens, the relationship between fungal spores and asthma is not fully explored. Only 80 taxa of fungi have so far been observed to exacerbate respiratory presentations, with Cladosporium spp., Aspergillus spp., Penicillium spp., and Alternaria spp. found to comprise the predominant allergenic airborne spores. Fungal spores have been found in indoor environments, such as hospitals and housing due to poor ventilation. Meanwhile, outdoor fungal spores exhibit greater diversity, and higher abundance and have been associated with hospitalizations from acute asthma presentations. In addition, fungal spores may be the underlying, and perhaps the “missing link”, factor influencing the heightened rate of asthma presentations during epidemic thunderstorm asthma events. To improve our knowledge gap on fungal spores, airborne allergen monitoring must be improved to include not only dominant allergenic fungi but also provide real-time data to accurately and quickly warn the general public. Such data will help prevent future asthma exacerbations and thus save lives. In this review, we examine the health risks of prominent allergenic fungal taxa, the factors influencing spore dispersal and distribution, and why improvements should be made to current sampling methods for public health and wellbeing.

Outdoor Mold and Respiratory Health: State of Science of Epidemiological Studies

BACKGROUND

Fungal spores are the predominant biological particulates in outdoor air. However, in contrast to pollens or outdoor air pollution, little is known about their respiratory health risks.

OBJECTIVES

The objectives were to conduct the first review of epidemiological studies on the short- and long-term effects of outdoor mold exposure on respiratory health in children and adults.

METHODS

Health outcomes included asthma, lung function, and rhinitis. Cross-sectional and longitudinal epidemiological studies using quantitative measures of outdoor mold exposure (optical microscopy, culture-based methods) were selected, providing that important confounding factors including temporal trends or meteorological factors were accounted for. A systematic literature search was performed up to June 2020, leading to the selection of 37 publications.

RESULTS

Most studies were longitudinal and investigated short-term effects. There is evidence of an association between outdoor fungal exposure and an increase in asthma exacerbation among children for total spores, 2 phyla (ascomycetes, basidiomycetes), and 2 taxa (Cladosporium, Alternaria). A few studies also suggested an association for Coprinus, Ganoderma, Aspergillus-Penicillium, Botrytis, and Epicoccum in children, but this needs to be confirmed. Some studies reported mold associations with rhinitis, lung function, and among adults, but these were few in number or inconsistent.

DISCUSSION

Further ecological studies in different regions that measure exposure to all taxa over several years are required to better understand their impact on rhinitis, asthma exacerbations and lung function. Larger panel studies are necessary to identify threshold effects in susceptible individuals. Finally, further research should assess the long-term effects of outdoor mold.

Interactive effects of allergens and air pollution on respiratory health: A systematic review

BACKGROUND

Studies have demonstrated an adverse role of outdoor allergens on respiratory symptoms. It is unknown whether this effect is independent or synergistic of outdoor air pollutants.

METHODS

We systematically reviewed all epidemiological studies that examined interaction effects between counts of outdoor airborne allergens (pollen, fungal spores) and air pollutants, on any respiratory health outcome in children and adults. We searched the MEDLINE, EMBASE and Scopus databases. Each study was summarized qualitatively and assessed for quality and risk of bias (International Prospective Register for Systematic Reviews, registration number CRD42020162571).

RESULTS

Thirty-five studies were identified (15 timeseries, eight case-crossovers, 11 panels and one cohort study), of which 12 reported a significant statistical interaction between an allergen and air pollutant. Eight interactions were related to asthma outcomes, including one on lung function measures and wheeze, three to medical consultations for pollinosis and one to allergic symptoms (nasal, ocular or bronchial). There was no consensus as to which allergen or air pollutant is more likely to interact. No study investigated whether interactions are stronger in atopic individuals.

CONCLUSION

Despite strong evidence from small experimental studies in humans, only a third of studies identified significant allergen-pollutant interactions using common epidemiological study designs. Exposure misclassification, failure to examine subgroups at risk, inadequate statistical power or absence of population-level effects are possible explanations.

Biochemical Characteristics and Allergenic Activity of Common Fungus Allergens

Fungi form a large kingdom with more than 1.5 million species. Fungal spores are universal atmospheric components and are generally recognized as important causes of allergic disorders, including allergic rhinitis, allergic rhinosinusitis, asthma, and allergic bronchopulmonary aspergillosis. The 4 genera which have the closest connection with allergic disorder are Cladosporium, Alternaria, Aspergillus and Penicillium. The cDNA sequences of many fungi allergens and the amino acids involved in their immunoglobulin E binding and T-cell activation have already been elucidated. Until now, 111 allergens from 29 fungal genera have been approved by the International Allergen Nomenclature Sub-committee. This review mainly focuses on the biochemical characteristics and allergenic activity of important allergens from common environmental fungi.

Environmental fungal sensitisation associates with poorer clinical outcomes in COPD

Introduction

Allergic sensitisation to fungi such as Aspergillus are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear.

Methods

Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome.

Results

High frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a “highly sensitised fungal predominant” subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD.

Conclusion

Fungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in “sensitised” COPD.

Fungal sensitisation associates with frequent exacerbations in COPD, and represents a treatable trait. Outdoor and indoor environments represent a key source of fungal allergen exposure, amenable to intervention, in “sensitised” COPD patients.https://bit.ly/2Vw3kHi

A Multifactorial Evaluation of the Effects of Air Pollution and Meteorological Factors on Asthma Exacerbation

In the real world, dynamic changes in air pollutants and meteorological factors coexist simultaneously. Studies identifying the effects of individual pollutants on acute exacerbation (AE) of asthma may overlook the health effects of the overall combination. A comprehensive study examining the influence of air pollution and meteorological factors is required. Asthma AE data from emergency room visits were collected from the Taiwan National Health Insurance Research Database. Complete monitoring data for air pollutants (SO₂; NO₂; O₃; CO; PM_2.5; PM₁₀) and meteorological factors were collected from the Environmental Protection Agency monitoring stations. A bi-directional case-crossover analysis was used to investigate the effects of air pollution and meteorological factors on asthma AE. Among age group divisions, a 1 °C temperature increase was a protective factor for asthma ER visits with OR = 0.981 (95% CI, 0.971–0.991) and 0.985 (95% CI, 0.975–0.994) for pediatric and adult patients, respectively. Children, especially younger females, are more susceptible to asthma AE due to the effects of outdoor air pollution than adults. Meteorological factors are important modulators for asthma AE in both asthmatic children and adults. When studying the effects of air pollution on asthma AE, meteorological factors should be considered.

The Role and Potential Pathogenic Mechanism of Particulate Matter in Childhood Asthma: A Review and Perspective

Asthma, the most common chronic respiratory disease in children, affects numerous people worldwide. Accumulating evidence suggests that exposure to high levels of particulate matter (PM), either acutely or chronically, is associated with the exacerbation and incidence of pediatric asthma. However, the detailed pathogenic mechanisms by which PM contributes to the incidence of asthma remain largely unknown. In this short review, we summarize studies of relationships between PM and pediatric asthma and recent advances on the fundamental mechanisms of PM-related asthma, with emphases on cell death regulation and immune system responses. We further discuss the inadequacy of current studies and give a perspective on the prevention strategies for pediatric asthma.

Short-term exposure to pollen and the risk of allergic and asthmatic manifestations: a systematic review and meta-analysis

BACKGROUND

Several studies have assessed effects of short-term exposure to pollen on allergic and asthmatic manifestations. The evidence is inconclusive, and no meta-analysis has been published.

OBJECTIVE

To synthesise the evidence on the relations between short-term pollen exposure and the risk of allergic and asthmatic manifestations.

METHODS

We performed a systematic literature search of PubMed and Scopus databases up to the end of August 2018. In addition, we reviewed the reference lists of relevant articles. Two authors independently evaluated the eligible articles and extracted relevant information in a structured form. We calculated summary effect estimates (EE) based on the study-specific ORs and regression coefficients (β) by applying both fixed-effects and random-effects models.

RESULTS

26 studies met the a priori eligibility criteria, and 12 of them provided sufficient information for the meta-analysis. The summary EE related to 10 grains per m³ increase in pollen exposure showed an 1% increase (EE 1.01, 95% CI 1.00 to 1.02) in the risk of lower respiratory symptoms and a 2% increase (EE 1.02, 95% CI 1.01 to 1.03) in the risk of any allergic or asthmatic symptom. Correspondingly, the risk of upper respiratory symptoms and ocular symptoms increased 7% (EE 1.07, 95% CI 1.04 to 1.09) and 11% (EE 1.11, 95% CI 1.05 to 1.17), respectively, in relation to such pollen exposure. Short-term exposure to pollen did not show any significant effect on daily lung function levels.

CONCLUSION

Our results provide new evidence that short-term pollen exposure significantly increases the risks of allergic and asthmatic symptoms.

Outdoor fungal spores and acute respiratory effects in vulnerable individuals

BACKGROUND

Many outdoor fungal spores are ubiquitous, respirable and possibly allergenic. They may contribute to asthma symptoms; however, little is known about their effects on respiratory function.

OBJECTIVE

To investigate if outdoor fungal spore levels were associated with lung function or airway inflammation, and whether fungal sensitization or current asthma modified any associations.

METHODS

Cross-sectional associations between same day (Lag0) and cumulative 3-day lagged (Lag0-3) counts of 12 outdoor fungal spore taxa and pre-bronchodilator spirometry (FEV₁, FVC, FEF_25%-75%), bronchodilator response (BDR) and airway inflammation (fractional exhaled nitric oxide (FeNO) and exhaled breath condensate (EBC) nitrogen oxides (NOx) and pH were investigated in 936 Melbourne Atopy Cohort Study participants during September 2009 to December 2011. Generalized linear models were used to quantify associations with lung function, FeNO and EBC pH; generalized estimating equations for BDR; and ordinal logistic regression for EBC NOx. Models were adjusted for age, sex, height, temperature, relative humidity, grass pollen and sample storage time. Potential effect modification by fungal sensitization and current asthma were examined using interaction terms.

RESULTS

Mixed associations were found. Higher levels of Ustilago/smuts were associated with lower lung function at Lag0 (FEV₁: 21ml [95%CI -36, -7]; FEF_25%-75%: 39ml [-65, -13]) and Lag0-3 (FEV₁: 9ml [-14, -4]; FEF_25%-75% -18ml [-27, -9]). Positive BDR was associated with Ustilago/smuts (Lag0 OR = 1.1 [1.04, 1.2]; Lag0-3 OR = 1.04 [1.02, 1.07]), Alternaria (Lag0 OR = 1.3 [1.0, 1.6]) and Drechslera (Lag0 OR = 1.1 [1.03, 1.2]). Higher EBC NOx was associated with Cladosporium (Lag0-3 OR = 1.1 [1.0, 1.2]), Alternaria (Lag0-3 OR = 1.1 [1.0, 1.3]). No associations were found with higher FeNO. In those with fungal sensitization, Ustilago/smuts and Drechslera were associated with lower FEV₁ and FVC; Cladosporium was associated with increased FEV₁, FVC and FEF_25%-75% but also with higher FeNO and lower EBC pH. In those with current asthma, Alternaria, Ustilago/smuts and Drechslera were associated with lower FEV₁, FVC, FEF_25-75% and EBC pH.

CONCLUSION

Exposure to outdoor fungal spores may be associated with lower lung function and increased airway inflammation, particularly in those with fungal sensitization and/or current asthma.

Short-acting β2-agonists (SABA) bronchodilator sales and outdoor mould in central France

Background

Temporal ecological studies have shown that outdoor moulds are associated with severe asthma exacerbations, as emergency department visits or hospitalisations. The aim of this was to assess the associations between daily sales of short-acting β2-agonists (SABA), a specific and frequent treatment for control of mild asthma exacerbations in children and young adults, and outdoor mould concentrations in the central France area over a 5 year period.

Methods

The relationship between daily changes in mould (25 species) concentrations and daily SABA sales within a population of patients aged 6 to 39 years in a middle-size town of central France (approximately 127,000) was obtained from social security database and analysed with generalized additive models, taking into account confounding factors (air pollution, weather conditions, pollen counts and trend).

Results

Daily SABA sales (mean, SD) rose from 17.3 (9.7) in 2010 to 22.7 (12) in 2015. The relative risk (RR [95% CI]) of SABA sales associated with an interquartile increase in mould concentration was significant in the whole population for Alternaria 1.06 [1.002–1.12]. When the influence of age and sex was accounted for, the relationship was significant only in 6–12 years old males for Alternaria 1.21 [1.04–1.41] and Aspergillus–Penicillium 1.08 [1.04–1.12].

Conclusions

Daily SABA sales are positively associated with Alternaria spores in the general population of children and young adults. The association between daily SABA sales and temporal changes to Alternaria and Aspergillus–Penicillium in male children indicate that outdoor moulds contribute to asthma morbidity.

Diurnal Variation of Sitagliptin-Induced Pharmacological Effects in C57BL/6J Mice

Chronopharmacology is the study of the varying responses of drugs to changes in biological timing and endogenous periodicities. The dipeptidyl peptidase-4 inhibitor sitagliptin is a globally prescribed anti-hyperglycemic drug. Although dipeptidyl peptidase-4 inhibitors are usually administered once, the specific intake time is generally not mentioned. Therefore, this study aimed at investigating the diurnal effects of sitagliptin-induced anti-hyperglycemia in high-fat diet (HFD)-induced obesity in mice. Five-week-old male C57BL/6J mice were fed normal (control) diet or HFD for 10 weeks. During the last 2 weeks, the mice were administered saline or sitagliptin (10 mg/kg, per os) in the light or dark phase, respectively. At the end of the experiment, the mice were euthanized after an 18 h fasting period, and plasma and tissue samples (liver, kidney, and epididymal white adipose tissues) were collected, or the oral glucose tolerance test was performed. Sitagliptin administration in the light phase significantly decreased plasma glucose levels, insulin levels, hepatic steatosis, and restored the glucose tolerance compared with the HFD group. In contrast, these parameters remained unchanged in the dark phase-treated mice. Our data therefore suggests that sitagliptin portrays definite chronopharmacology, which may provide valuable information on the importance of drug administration timing for maximum pharmacological effects.

Fungal aerosol composition in moldy basements

Experimental aerosolization studies revealed that fungal fragments including small fragments in the submicrometer size are released from fungal cultures and have been suggested to represent an important fraction of overall fungal aerosols in indoor environments. However, their prevalence indoors and outdoors remains poorly characterized. Moldy basements were investigated for airborne fungal particles including spores, submicron fragments, and larger fragments. Particles were collected onto poly-L-lysine-coated polycarbonate filters and qualitatively and quantitatively analyzed using immunogold labeling combined with field emission scanning electron microscopy. We found that the total fungal aerosol levels including spores, submicrometer, and larger fragments in the moldy basements (median: 80 × 10³  m^-3 ) were not different from that estimated in control basements (63 × 10³  m^-3 ) and outdoor (90 × 10³  m^-3 ). However, mixed effect modeling of the fungal aerosol composition revealed that the fraction of fragments increased significantly in moldy basements, versus the spore fraction that increased significantly in outdoor air. These findings provide new insight on the compositional variation of mixed fungal aerosols in indoor as compared to outdoor air. Our results also suggest that further studies, aiming to investigate the role of fungal aerosols in the fungal exposure-disease relationships, should consider the mixed composition of various types of fungal particles.

Chronopharmacology of dapagliflozin-induced antihyperglycemic effects in C57BL/6J mice

Chronopharmacology is the study of the varying responses of drugs to changes in biological timing and endogenous periodicities. The selective sodium-glucose cotransporter 2 inhibitor, dapagliflozin, is a globally prescribed antihyperglycemic drug. Although dapagliflozin is usually administered once a day, the specific intake time is generally not mentioned. Therefore, this study aimed at investigating the diurnal effects of dapagliflozin on high-fat diet (HFD)-induced obesity in mice. Five-week-old male C57BL/6J mice were fed a normal (control) diet or HFD for 10 weeks. During the last 2 weeks, the mice were administered olive oil/ethanol emulsion or dapagliflozin (1mg/kg, p.o.) in the light or dark phase. At the end of the experiment, the mice were euthanized after an 18h fasting period, and plasma and tissue samples (epididymal white adipose tissues, liver, and kidney) were collected. Dapagliflozin administration in the light phase significantly decreased plasma glucose levels, insulin levels, adipose adipokines, and decreased the size of adipocytes, compared with the HFD group. In contrast, these parameters remained unchanged in the mice treated during the dark phase. Our data therefore suggests that dapagliflozin portrays definite chronopharmacology, which may provide valuable information on the importance of drug administration timing for maximal pharmacological effects.

Immunological Factors Associated with Adult Asthma in the Aseer Region, Southwestern Saudi Arabia

Background: The prevalence of asthma is on the rise in Saudi Arabia. Data regarding the immunological profile of asthma in adults in the Aseer region, in southwestern Saudi Arabia, have not been well studied. Objectives: Our aim was to study the immunological factors associated with sensitization to asthma among adults in the Aseer region. Methods: A cross-sectional study with a nested case control design in a 1:1 ratio was conducted on a sample of adults attending primary health care centers in the Aseer region. The study used a validated Arabic version of the International study of asthma and allergies in childhood (ISAAC) questionnaire. The presence of wheezing in the past 12 months was used as a proxy for bronchial asthma. Matched age and sex controls were selected. Both groups were tested for complete blood count (CBC), total and differential white blood cell (WBC) count including eosinophils, total immunoglobulin E (IgE) measurement, allergen-specific immunoglobulin E (IgE), and cytokine levels. Results: The present study included 110 cases and 157 age- and sex-matched controls. Rye wheat was found to be a significant outdoor sensitizing agent ((odds ratio) OR = 5.23, 95% CI: 1.06–25.69). Indoors, house dust mites Dermatophagoides petronyssinus (OR = 2.04, 95% CI: 1.04–3.99) and Dermatophagoides farinae (OR = 2.50, 95% CI: 1.09–5.75) were significant. Higher total IgE (OR = 1.84, 95% CI: 1.10–3.06) and eosinophil levels (OR = 2.85, 95% CI: 1.14–7.15) were significantly associated with adult bronchial asthma in Aseer. On the other hand, the role of cytokines was not significant. Conclusions: In the present study, certain environmental agents were found to be important with regards to sensitization to bronchial asthma in adults. Knowledge about these sensitization agents should be disseminated to health providers and treating physicians in order to enhance preventive environmental control measures and asthma management. Asthma-treating physicians in the region should be alerted to the use of targeted biological therapies in selected asthmatics with difficult-to-control courses.

Fungal Fragments and Fungal Aerosol Composition in Sawmills

Assessment of exposure to fungi has commonly been limited to fungal spore measurements that have shown associations between fungi and development or exacerbation of different airway diseases. Because large numbers of submicronic fragments can be aerosolized from fungal cultures under laboratory conditions, it has been suggested that fungal exposure is more complex and higher than that commonly revealed by spore measurements. However, the assessment of fungal fragments in complex environmental matrix remain limited due to methodological challenges. With a recently developed immunolabeling method for field emission scanning electron microscope (FESEM), we could assess the complex composition of fungal aerosols present in personal thoracic samples collected from two Norwegian sawmills. We found that large fungal fragments (length >1 µm) dominated the fungal aerosols indicating that the traditional monitoring approach of spores severely underestimate fungal exposure. The composition of fungal aerosols comprised in average 9% submicronic fragments, 62% large fragments, and 29% spores. The average concentrations of large and submicronic fragments (0.2–1 µm) were 3 × 10⁵ and 0.6 × 10⁵ particles m⁻³, respectively, and correlated weakly with spores (1.4 × 10⁵ particles m⁻³). The levels of fragments were 2.6 times higher than the average spore concentration that was close to the proposed hazardous level of 10⁵ spores per m³. The season influenced significantly the fungal aerosol concentrations but not the composition. Furthermore, the ratio of spores in the heterogeneous fungal aerosol composition was significantly higher in saw departments as compared to sorting of green timber departments where the fungal fragments were most prevalent. Being the dominating particles of fungal aerosols in sawmills, fungal fragments should be included in exposure-response studies to elucidate their importance for health impairments. Likewise, the use of fungal aerosol composition in such studies should be considered.

Association of molds and metrological parameters to frequency of severe asthma exacerbation

Background

Sensitization to airborne molds may be a risk factor for severe asthma and direct cause of asthma exacerbation (AE).

Methods

A prospective, 1-year (April 2016-March 2017) study, done in Kuwait Allergy Centre, investigated the link between AEs with exposure to outdoor molds and the role of meteorological parameters in mold sensitized patients and compared with non-allergic asthma patients who had asthma deterioration. The total of 676 adult asthmatics with moderate-severe AEs were included and divided into atopic (85.65%) and non-atopic group. Atopy was defined by positive skin prick test (SPT) to at least one inhalant allergen. Data regarding atopy and asthma severity were collected from patient's records. Patients with symptoms and signs of acute respiratory infection and patient sensitized to indoor allergens only were excluded. Daily count of local pollens (Salsola kali, Bermuda grass) and molds (Aspergillus, Alternaria and Cladosporium) were obtained from the Aerobiology department. Daily metrological parameters (atmospheric pressure-AP, temperature-T and relative humidity-RH) were provided by Kuwait Environment Public Authority. Count of spores/m³ and weather variable are shown on weekly basis. The year circle was divided into 4 Seasons (1, 2, 3, 4) accordingly to typical desert climate.

Results

Sensitization to molds was relatively high but significantly less (25.0%) if compared to the pollens sensitization. The highest number of AEs was in season 4 for both molds and pollens sensitized patients. Seasonal patterns for both allergens were significant and positively correlated with RH and AP. In season 1 only, mold sensitized patients showed higher rate of AEs. Non-atopic patients have been less sensitive to increased RH than atopic. Negative correlation with T was similar in both atopic and non-atopic patients.

Conclusion

Despite of high rate of sensitization to molds, their significant role in triggering AE was not found in desert environment. Typical desert climate and high allergencity of local weeds outweigh the influence of the molds.

Temporal variability in the allergenicity of airborne Alternaria spores

The concentration of fungal spores in the air is traditionally considered as a proxy of allergen exposure. However, in vitro experiments have shown that the allergenicity of Alternaria spores varies depending on ecophysiological and developmental factors. Despite the potential clinical significance of these findings, it has never been verified in outdoor environments. This study, therefore, aims to investigate variability in the amount of the major allergen (Alt a 1) released from Alternaria spores in outdoor air. During the 3-year monitoring study (2014-2016), the median seasonal allergenicity of Alternaria spores exceeded 8.6 × 10-3 pg Alt a 1/spore. The most allergenic spores were collected during the driest and the most polluted season (with respect to seasonal concentrations of ozone, sulphur dioxide, and particulate matter). Within the season, daily spore allergenicity ranged from 2.4 to 34.7 × 10-3 pg Alt a 1/spore (5th-95th percentile). No repeatable effects of weather and pollution on short-term variations in Alternaria spore allergenicity were found. However, during the episodes when high-potency spores were recorded, the air masses arrived from eastern directions. Contrary, the spores with the lowest allergenicity were related to western winds. This suggests that factors such as source area (habitat types) and species diversity could be responsible for the varying exposure to Alternaria allergens. Our findings show that high and low-potency spores are recorded in the air; therefore, the airborne concentrations of fungal spores alone may not be sufficient to provide allergy sufferers and healthcare professionals with information about allergen exposure.

Influence of Air Pollution on Hospital Admissions in Adult Asthma in Northeast China

Background:

Asthma is a common chronic respiratory disease and is related to air pollution exposure. However, only a few studies have concentrated on the association between air pollution and adult asthma. Moreover, the results of these studies are controversial. Therefore, the present study aimed to analyze the influence of various pollutants on hospitalization due to asthma in adults.

Methods:

A total of 1019 unrelated hospitalized adult asthma patients from Northeast China were recruited from 2014 to 2016. Daily average concentrations of air pollutants (particulate matter <2.5 μm [PM_2.5], particulate matter <10 μm [PM₁₀], sulfur dioxide [SO₂], nitrogen dioxide [NO₂], and carbon monoxide [CO]) were obtained from the China National Environmental Monitoring Centre website from 2014 to 2016. Cox logistic regression analysis was used to analyze the relationship between air pollutants and hospital admissions in adult asthma.

Results:

The maximum odds ratio (OR) value for most air pollutants occurred on lag day 1. Lag day 1 was chosen as the exposure period, and 8 days before onset was chosen as the control period. Three pollutants (PM_2.5, CO, and SO₂) were entered into the regression equation, and the corresponding OR (95% confidence interval) was 0.995 (0.991–0.999), 3.107 (1.607–6.010), and 0.979 (0.968–0.990), respectively.

Conclusions:

A positive association between hospital admissions and the daily average concentration of CO was observed. CO is likely to be a risk factor for hospital admissions in adults with asthma.

[Outdoor moulds and respiratory health]

Mould spores constitute the largest portion of biologic particulate matter suspended in the outdoor atmosphere. There is no universal method for collecting airborne mould spores. The most used sampler, Hirst's apparatus, operates continuously and gives results in individual spores per cubic metre of air. Spore concentrations depend on available substrates, human activities such as agriculture, season, diurnal meteorological variations and climate changes. Under natural conditions, concentrations of over 100,000 spores per cubic metre are not exceptional. Cladosporium is the most commonly identified outdoor mould. The association between respiratory health and outdoor mould spore exposure has been assessed in clinical studies, and also by cross-sectional, and less often longitudinal, epidemiological studies. The relationship between asthma exacerbations and specific mould spores has been demonstrated in longitudinal studies. Cross sectional studies have related measurements of mould spore concentrations to severity of bronchial symptoms, drug consumption and peak-flow measurements in groups of asthmatic subjects. Ecological time-series studies use daily indicators of asthma exacerbations (emergency room visits, hospitalizations) within the general population. The moulds mainly incriminated are Cladosporium and Alternaria. They are associated with seasonal, but also perennial, asthma and rhinitis. Further studies are needed to better assess the impact of outdoor moulds on health, particularly basidiomycetes. Studies with molecular biology tools are probably a way forward.

Interleukin-33 is activated by allergen- and necrosis-associated proteolytic activities to regulate its alarmin activity during epithelial damage

Interleukin (IL)-33 is an IL-1 family alarmin released from damaged epithelial and endothelial barriers to elicit immune responses and allergic inflammation via its receptor ST2. Serine proteases released from neutrophils, mast cells and cytotoxic lymphocytes have been proposed to process the N-terminus of IL-33 to enhance its activity. Here we report that processing of full length IL-33 can occur in mice deficient in these immune cell protease activities. We sought alternative mechanisms for the proteolytic activation of IL-33 and discovered that exogenous allergen proteases and endogenous calpains, from damaged airway epithelial cells, can process full length IL-33 and increase its alarmin activity up to ~60-fold. Processed forms of IL-33 of apparent molecular weights ~18, 20, 22 and 23 kDa, were detected in human lungs consistent with some, but not all, proposed processing sites. Furthermore, allergen proteases degraded processed forms of IL-33 after cysteine residue oxidation. We suggest that IL-33 can sense the proteolytic and oxidative microenvironment during tissue injury that facilitate its rapid activation and inactivation to regulate the duration of its alarmin function.

Can Controlling Endoplasmic Reticulum Dysfunction Treat Allergic Inflammation in Severe Asthma With Fungal Sensitization?

Severe asthma is a heterogeneous disease entity to which diverse cellular components and pathogenetic mechanisms contribute. Current asthma therapies, including new biologic agents, are mainly targeting T helper type 2 cell-dominant inflammation, so that they are often unsatisfactory in the treatment of severe asthma. Respiratory fungal exposure has long been regarded as a precipitating factor for severe asthma phenotype. Moreover, as seen in clinical definitions of allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS), fungal allergy-associated severe asthma phenotype is increasingly thought to have distinct pathobiologic mechanisms requiring different therapeutic approaches other than conventional treatment. However, there are still many unanswered questions on the direct causality of fungal sensitization in inducing severe allergic inflammation in SAFS. Recently, growing evidence suggests that stress response from the largest organelle, endoplasmic reticulum (ER), is closely interconnected to diverse cellular immune/inflammatory platforms, thereby being implicated in severe allergic lung inflammation. Interestingly, a recent study on this issue has suggested that ER stress responses and several associated molecular platforms, including phosphoinositide 3-kinase-δ and mitochondria, may be crucial players in the development of severe allergic inflammation in the SAFS. Defining emerging roles of ER and associated cellular platforms in SAFS may offer promising therapeutic options in the near future.

Alternaria alternata acts on human Monocyte-derived Dendritic cells to mediate Th2/Th17 polarisation

INTRODUCTION

Although the mechanism of asthma is not precisely understood in humans, clinical and epidemiological studies have offered a potential relationship between exposure to environmental fungi, such as Alternaria alternata (A. alternata) and the development and exacerbation of asthma. The aim of this project is to investigate the mechanisms of Th2 responses by A. alternata as a clinically relevant model for the environmental exposure.

MATERIALS AND METHODS

Plastic adherent monocytes were cultured with granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) to convert these cells into Monocyte-derived Dendritic cells (MoDc) and then matured in the presence of Monocyte-Conditioned Medium (MCM) as the control group and MCM+ A. alternata extract as the inductive groups.

RESULTS

The results indicated that the expression of CD14 decreased and CD83 and anti-human leukocyte antigen-DR (HLA-DR) increased in the inductive groups in comparison with the control group. More importantly, A. alternata inhibited IL-12 production by activated dendritic cells (DCs), and the DCs exposed to A. alternata enhanced the Th2 polarisation of CD4⁺ T cells. The production amount of IL-10 overcame IL-12 as well as Il-23 increased significantly, and hand in T cells the production of cytokines Interferon-γ (IFN-γ) decreased. However, both IL-17 and IL-4 increased (p<0.05). Phagocytic activity in the inductive groups decreased significantly compared with the control group.

CONCLUSION

The asthma-related environmental fungus A. alternata, with an effect on dendritic cells profile mediates TH2/TH17. Such immunodysregulation properties of causative environmental fungi may explain their strong relationship with human asthma and allergic diseases.

The effect of size-segregated ambient particulate matter on Th1/Th2-like immune responses in mice

Background

Particulate matter (PM) has been associated with increased pulmonary and cardiovascular mortality and morbidity. Additionally, PM is known to exacerbate asthma. However, whether ambient PM exposure contributes to the onset of asthma, especially in non-atopic children and adults, is less conclusive. The current study aimed to evaluate the effects of size-fractioned PM on lung immune responses in healthy BALB/c mice.

Methods and principal findings

We collected PM₁₀, PM_2.5, PM₁ and PM_0.1 samples from October 2012 to August 2013 in the Taipei Basin. These PM samples were representative of urban traffic pollution. The samples were extracted and sonicated in phosphate-buffered saline (PBS). Female BALB/c mice were exposed to the samples via intratracheal instillation at three different doses: 1.75 mg/kg (35 μg/per mouse), 5 mg/kg (100 μg/per mouse), and 12.5 mg/kg (250 μg/per mouse). The mice were exposed on days 0 and 7, and PBS alone was used as a control. Following the exposures, the expression profiles of inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were assessed. Exposure to PM₁₀ resulted in inflammatory responses, including the recruitment of neutrophils and the induction of T helper 1 (Th1) cell-related cytokine release, such as TNF-α and IFN-γ. Furthermore, an allergic immune response, including the recruitment of eosinophils and the up-regulation of T helper 2 (Th2) cell-related cytokine release, such as IL-5 and IL-13, was also observed in the BALF of mice exposed to PM₁₀.

Conclusions

Our study showed that exposure to PM alone caused mixed Th1/Th2 inflammatory responses in healthy mice. These findings support the hypothesis that PM may contribute to the onset of asthma.

Association between Outdoor Fungal Concentrations during Winter and Pulmonary Function in Children with and without Asthma

Outdoor fungi are important components of airborne particulate matter (PM). However, the associations between pulmonary function and outdoor fungi are less well known compared to other airborne PM constituents. The objective of this study was to investigate the association between outdoor fungi and pulmonary function in children. Morning peak expiratory flow (PEF) rates were measured daily in 339 schoolchildren (including 36 with asthma), aged 10 to 12, 2 to 27 February 2015. Airborne PM was collected on filters, using a high volume air sampler, each day during the study period. The daily concentration of outdoor fungi-associated PM was calculated using a culture-based method. A linear mixed model was used to estimate the association between PEF values and daily concentrations of outdoor fungi, and the daily levels of suspended PM (SPM) and PM ≤ 2.5 μm (PM_2.5). An increase in the interquartile range (46.2 CFU/m³) for outdoor fungal concentration led to PEF changes of −1.18 L/min (95% confidence interval, −2.27 to −0.08) in all children, 1.22 L/min (−2.96 to 5.41) in children without asthma, and −1.44 L/min (−2.57 to −0.32) in children with asthma. Outdoor fungi showed a significant negative correlation with PM_2.5 levels (r = −0.4, p = 0.04), but not with SPM (r = ‒0.3, p = 0.10) levels. Outdoor fungi may be associated with pulmonary dysfunction in children. Furthermore, children with asthma may show greater pulmonary dysfunction than those without asthma.

Association between Ambient Air Pollution and Asthma Prevalence in Different Population Groups Residing in Eastern Texas, USA

Air pollution has been an on-going research focus due to its detrimental impact on human health. However, its specific effects on asthma prevalence in different age groups, genders and races are not well understood. Thus, the present study was designed to examine the association between selected air pollutants and asthma prevalence in different population groups during 2010 in the eastern part of Texas, USA.The pollutants considered were particulate matter (PM2.5 with an aerodynamic diameter less than 2.5 micrometers) and surface ozone. The population groups were categorized based on age, gender, and race. County-wise asthma hospital discharge data for different age, gender, and racial groups were obtained from Texas Asthma Control Program, Office of Surveillance, Evaluation and Research, Texas Department of State Health Services. The annual means of the air pollutants were obtained from the United States Environmental Protection Agency (U.S. EPA)'s air quality system data mart program. Pearson correlation analyzes were conducted to examine the relationship between the annual mean concentrations of pollutants and asthma discharge rates (ADR) for different age groups, genders, and races. The results reveal that there is no significant association or relationship between ADR and exposure of air pollutants (PM2.5, and O₃). The study results showed a positive correlation between PM2.5 and ADR and a negative correlation between ADR and ozone in most of the cases. These correlations were not statistically significant, and can be better explained by considering the local weather conditions. The research findings facilitate identification of hotspots for controlling the most affected populations from further environmental exposure to air pollution, and for preventing or reducing the health impacts.

Concentration and size distribution of total airborne microbes in hazy and foggy weather

Atmospheric bioaerosol particles were collected using a bioaerosol sampler from Oct. 2013 to Aug. 2014 in the coastal region of Qingdao. The total microbes were measured using an epifluorescence microscope after staining with DAPI (4',6-diamidino-2-phenylindole). The concentration of total airborne microbes showed seasonal variation, with the highest value in winter and the lowest in summer. The mean concentration of total microbes was 6.55 × 10(5)Cells/m(3) on non-hazy days. The total microbe concentration increased to 7.09 × 10(5) and 9.00 × 10(5)Cells/m(3) on hazy and foggy days, respectively. The particle sizes of the total microbes presented a bimodal distribution on sunny days, with one peak at 1.1-2.1 μm and another at 4.7-7.0 μm. The size distribution of total microbes showed an increase in the fine fraction on hazy days and an increase in the coarse fraction on foggy days. However, the size distribution became unimodal during a heating period. Spearman correlation analysis showed that temperature and O3 had a significant negative correlation with the airborne microbe concentration, while PM2.5, SO2, NO2, CO and the air quality index (AQI) had significant positive correlations with the airborne microbe concentration during hazy days. The increased number of airborne microbes will affect the air quality on hazy days.

Sensitization to fungal allergens: Resolved and unresolved issues

Exposure and sensitization to fungal allergens can promote the development and worsening of allergic diseases. Although numerous species of fungi have been associated with allergic diseases in the literature, the significance of fungi from the genera Alternaria, Cladosporium, Penicillium, Aspergillus, and Malassezia has been well documented. However, it should be emphasized that the contribution of different fungal allergens to allergic diseases is not identical, but species-specific. Alternaria and Cladosporium species are considered to be important outdoor allergens, and sensitization and exposure to species of these genera is related to the development of asthma and rhinitis, as well as epidemics of asthma exacerbation, including life-threatening asthma exacerbation. In contrast, xerophilic species of Penicillium and Aspergillus, excluding Aspergillus fumigatus, are implicated in allergic diseases as indoor allergens. A. fumigatus has a high capacity to colonize the bronchial tract of asthmatic patients, causing severe persistent asthma and low lung function, and sometimes leading to allergic bronchopulmonary aspergillosis. Malassezia are common commensals of healthy skin, although they are also associated with atopic dermatitis, especially on the head and neck, but not with respiratory allergies. Despite its importance in the management of allergic diseases, precise recognition of species-specific IgE sensitization to fungal allergens is often challenging because the majority of fungal extracts exhibit broad cross-reactivity with taxonomically unrelated fungi. Recent progress in gene technology has contributed to the identification of specific and cross-reactive allergen components from different fungal sources. However, data demonstrating the clinical relevance of IgE reactivity to these allergen components are still insufficient.

Alt a 15 is a new cross-reactive minor allergen of Alternaria alternata

Alternaria alternata is one of the most common saprophytes worldwide that is clinically and epidemiologically associated with severe asthma. Therefore, the identification and characterization of all A. alternata allergens are of major clinical importance. This study describes a new cross-reactive A. alternata allergen that was officially named Alt a 15 by the official Allergen Nomenclature Subcommittee. The complete coding region for Alt a 15 was amplified using 5' and 3' rapid amplification of cDNA ends and PCR. The recombinant protein was produced in Escherichia coli as a 65-kDa fusion protein, and the protein sequence exhibits high homology with several important fungal allergens. Immunoblotting analyses revealed that IgE antibodies from A. alternata-sensitized patients (n=59) bound to rAlt a 15 with a prevalence of 10.2%. All patients who presented sIgE to rAlt a 15 were apparently poly-sensitized to A. alternata and C. lunata. The extensive cross-reactivity between A. alternata and C. lunata serine proteases was confirmed using immunoblotting inhibition assays. Overall, Alt a 15 is an important new cross-reactive allergen of A. alternata that explains some allergies to A. alternata without Alt a 1 sensitization and initial diagnostic errors for allergies to Alternaria. This molecule may improve the accuracy of the diagnosis, the understanding, and the management of IgE-mediated fungal diseases.

Antifungals in severe asthma

PURPOSE OF REVIEW

Despite guideline-based treatment, many patients with severe asthma continue to have uncontrolled disease. Fungal allergy is being increasingly recognized in the pathogenesis of severe asthma. Limited data exist on the approach to treatment of fungal asthma. This review summarizes existing evidence on the use of antifungal agents in allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS), and highlights needed areas of future investigation.

RECENT FINDINGS

Recent studies evaluating oral triazole therapy in ABPA appear to support triazole use in a carefully considered clinical setting, whereas studies assessing triazole use in SAFS have yielded mixed results. Despite early encouraging findings that oral triazole use may improve asthma symptoms, stabilize lung function, decrease inhaled and systemic corticosteroid requirements, and alter serum biomarkers, overall data are limited. Appropriate patient selection, as well as choice of the optimal drug, dose, frequency, and duration of therapy, remains poorly defined.

SUMMARY

The role of antifungal therapy in severe asthma remains unclear. Early studies have suggested a possible benefit of some antifungal agents, such as oral triazoles in ABPA and SAFS; however, routine clinical use of these agents in severe asthma without ABPA is not currently recommended. Further research is needed to better delineate the potential utility of antifungal medications in severe asthma and identify the asthma populations who benefit from such treatment.

Association between Chronic Laryngitis and Particulate Matter Based on the Korea National Health and Nutrition Examination Survey 2008-2012

Background

Chronic laryngitis (CL) has been described as chronic inflammation of the larynx. CL have various causes such as long-term smoking, acid reflux, voice overuse, bronchitis, allergies, pneumonia, excessive exposure to toxic chemicals and complications from the flu or a chronic cold. However, the prevalence of CL and role of air pollution in the etiology is uncertain.

Objective

The aim of this study was to investigate the relationship between CL and particulate matter with aerodynamic diameter less than 10 μm (PM₁₀) in South Korea using data from the Korea National Health and Nutrition Examination Surveys (KNHANES) during 2008–2012.

Methods

KNHANES is a cross-sectional survey of the civilian, non-institutionalized population of South Korea (n = 21,116). A field survey team that included an otolaryngologist moved with a mobile examination unit and performed interviews and physical examinations. The mean annual concentrations of ambient PM10, SO2, O3, NO2, and CO levels in Korea were determined from monitoring station data. Multiple logistic regression was used to examine the relationship of air pollution to CL.

Results

Among the population ≥ 19 years of age, the weighted prevalence of CL was 3.37 ± 0.30% (95% confidence interval, 2.79–3.95%). CL was more prevalent in men, current smokers, and those with lower household income and prevalence increased with age. A significant decrease over time was observed in the prevalence of CL (P for trend = 0.0049) and the annual average concentrations of PM₁₀ (P for trend < 0.0001) from 2008 to 2012. In a multivariate model, the factors associated with CL included PM₁₀ (odds ratio [OR], 1.378, p = 0.0457), age (OR, 1.020, p<0.0001), sex (OR, 0.734, p = 0.0179), and smoking status (OR, 1.438, p = 0.0054).

Conclusion

Elevated PM10 exposures could be associated with increased risk of CL in South Koreans. Further epidemiological and experimental studies are necessary to clarify the impact of chronic PM₁₀ exposure on CL.

ILC2s and fungal allergy

Innate lymphoid cells (ILCs) have emerged recently as an important component of the immune system and the cell type that regulates mucosal immune responses and tissue homeostasis. Group 2 ILCs (ILC2s), a subset of ILCs, reside in various tissues and are characterized by their capacity to produce type 2 cytokines and tissue growth factors. These ILC2s play an important role in allergic immune responses by linking signals in the atmospheric environment to the immune system. Fungi are one of the major allergens associated with human asthma, and animal and in vitro models using the fungal allergens have provided significant information toward our understanding of the mechanisms of allergic disease. In mouse models of fungus-induced allergic airway inflammation, IL-33, IL-25, and TSLP are released by airway epithelial cells. Lung ILC2s that respond to these cytokines quickly produce a large quantity of type 2 cytokines, resulting in airway eosinophilia, mucus production, and airway hyperreactivity even in the absence of adaptive immune cells. Evidence also suggests that ILC2s interact with conventional immune cells, such as CD4⁺ T cells, and facilitate development of adaptive immune response and persistent airway inflammation. ILC2s are also present in respiratory mucosa in humans. Further investigations into the biology of ILC2s and their roles in the pathophysiology of allergic diseases will provide major conceptual advances in the field and may provide useful information toward development of new therapeutic strategies for patients.

Outdoor fungi and child asthma health service attendances

Asthma is a significant global public health issue. Severe asthma exacerbations can be triggered by environmental factors and require medical care from health services. Although it is known that fungal exposure may lead to allergic sensitization, little is understood about its impact on asthma exacerbations. This review aims to examine whether outdoor fungi play a significant role in child asthma exacerbations. Systematic search of seven electronic databases and hand searching for peer-reviewed studies published in English, up to 31 August 2013. Inclusion criteria were study population aged <18 yr, diagnosis of asthma, attended a health service; outdoor fungi exposure was reported. Quality and risk of bias assessments were conducted. Due to significant heterogeneity, meta-analysis was not conducted. Of the 1896 articles found, 15 were eligible. Findings were not consistent, possibly due to methodological variations in exposure classifications, statistical methods and inclusion of confounders. Cross-sectional studies found no or weak associations. All but one time series studies indicated an association that varied between fungal species. Increasing evidence indicates that asthmatic children are susceptible to asthma exacerbations when exposed to outdoor fungal spores. There is limited understanding of the contributions of different fungal species. Research is needed to investigate interactions of outdoor fungi with pollen, air pollutants and respiratory viruses.

A GIS based approach for assessing the association between air pollution and asthma in New York State, USA

Studies on asthma have shown that air pollution can lead to increased asthma prevalence. The aim of this study is to examine the association between air pollution (fine particulate matter (PM_2.5), sulfur dioxide (SO₂) and ozone (O₃)) and human health (asthma emergency department visit rate (AEVR) and asthma discharge rate (ADR)) among residents of New York, USA during the period 2005 to 2007. Annual rates of asthma were calculated from population estimates for 2005, 2006, and 2007 and number of asthma hospital discharge and emergency department visits. Population data for New York were taken from US Bureau of Census, and asthma data were obtained from New York State Department of Health, National Asthma Survey surveillance report. Data on the concentrations of PM_2.5, SO₂ and ground level ozone were obtained from various air quality monitoring stations distributed in different counties. Annual means of these concentrations were compared to annual variations in asthma prevalence by using Pearson correlation coefficient. We found different associations between the annual mean concentration of PM_2.5, SO₂ and surface ozone and the annual rates of asthma discharge and asthma emergency visit from 2005 to 2007. A positive correlation coefficient was observed between the annual mean concentration of PM_2.5, and SO₂ and the annual rates of asthma discharge and asthma emergency department visit from 2005 to 2007. However, the correlation coefficient between annual mean concentrations of ground ozone and the annual rates of asthma discharge and asthma emergency visit was found to be negative from 2005 to 2007. Our study suggests that the association between elevated concentrations of PM_2.5 and SO₂ and asthma prevalence among residents of New York State in USA is consistent enough to assume concretely a plausible and significant association.

Outdoor air pollution and asthma

Traffic and power generation are the main sources of urban air pollution. The idea that outdoor air pollution can cause exacerbations of pre-existing asthma is supported by an evidence base that has been accumulating for several decades, with several studies suggesting a contribution to new-onset asthma as well. In this Series paper, we discuss the effects of particulate matter (PM), gaseous pollutants (ozone, nitrogen dioxide, and sulphur dioxide), and mixed traffic-related air pollution. We focus on clinical studies, both epidemiological and experimental, published in the previous 5 years. From a mechanistic perspective, air pollutants probably cause oxidative injury to the airways, leading to inflammation, remodelling, and increased risk of sensitisation. Although several pollutants have been linked to new-onset asthma, the strength of the evidence is variable. We also discuss clinical implications, policy issues, and research gaps relevant to air pollution and asthma.

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

Sensitization to fungi and long term or uncontrolled fungal infection are associated with poor control of asthma, the likelihood of more severe disease and complications such as bronchiectasis and chronic pulmonary aspergillosis. Modelling suggests that >6.5 million people have severe asthma with fungal sensitizations (SAFS), up to 50% of adult asthmatics attending secondary care have fungal sensitization, and an estimated 4.8 million adults have allergic bronchopulmonary aspergillosis (ABPA). There is much uncertainty about which fungi and fungal allergens are relevant to asthma, the natural history of sensitisation to fungi, if there is an exposure response relationship for fungal allergy, and the pathogenesis and frequency of exacerbations and complications. Genetic associations have been described but only weakly linked to phenotypes. The evidence base for most management strategies in ABPA, SAFS and related conditions is weak. Yet straightforward clinical practice guidelines for management are required. The role of environmental monitoring and optimal means of controlling disease to prevent disability and complications are not yet clear. In this paper we set out the key evidence supporting the role of fungal exposure, sensitisation and infection in asthmatics, what is understood about pathogenesis and natural history and identify the numerous areas for research studies.

Alternaria-derived serine protease activity drives IL-33-mediated asthma exacerbations

Background

The fungal allergen Alternaria alternata is implicated in severe asthma and rapid onset life-threatening exacerbations of disease. However, the mechanisms that underlie this severe pathogenicity remain unclear.

Objective

We sought to investigate the mechanism whereby Alternaria was capable of initiating severe, rapid onset allergic inflammation.

Methods

IL-33 levels were quantified in wild-type and ST2^−/− mice that lacked the IL-33 receptor given inhaled house dust mite, cat dander, or Alternaria, and the effect of inhibiting allergen-specific protease activities on IL-33 levels was assessed. An exacerbation model of allergic airway disease was established whereby mice were sensitized with house dust mite before subsequently being challenged with Alternaria (with or without serine protease activity), and inflammation, remodeling, and lung function assessed 24 hours later.

Results

Alternaria, but not other common aeroallergens, possessed intrinsic serine protease activity that elicited the rapid release of IL-33 into the airways of mice through a mechanism that was dependent upon the activation of protease activated receptor-2 and adenosine triphosphate signaling. The unique capacity of Alternaria to drive this early IL-33 release resulted in a greater pulmonary inflammation by 24 hours after challenge relative to the common aeroallergen house dust mite. Furthermore, this Alternaria serine protease–IL-33 axis triggered a rapid, augmented inflammation, mucus release, and loss of lung function in our exacerbation model.

Conclusion

Alternaria-specific serine protease activity causes rapid IL-33 release, which underlies the development of a robust T_H2 inflammation and exacerbation of allergic airway disease.

Size-selective assessment of agricultural workers' personal exposure to airborne fungi and fungal fragments

Fungi are ubiquitous agents that cause human respiratory diseases. Very few studies have size-selectively assessed farmers' exposure to fungi and fungal fragments in agricultural settings. In this study, a two-stage bio-aerosol cyclone personal sampler was employed to collect airborne fungi and fungal fragments size-selectively at corn, swine, poultry, and mushroom farms. The collected air samples were analyzed for culturable fungi, fungal spores, viable fungi and (1 → 3)-β-D-glucan. The results show that the median concentrations ranged from 3.2 × 10(5) to 1.3 × 10(8)spores/m(3) for total fungal spores, from 1.3 × 10(5) to 5.1 × 10(7)spores/m(3) for total viable fungi, from 1.9 × 10(3) to 1.5 × 10(7)CFU/m(3) for total culturable fungi, and from 4.3 × 10(3) to 2.4 × 10(6)pg/m(3) for total (1 → 3)-β-D-glucan. The aerodynamic sizes of most of the collected fungal contaminants were larger than 1.8 μm. Total (1 → 3)-β-D-glucan significantly correlated with total fungal spores (r = 0.65, p < 0.001), total viable fungi (r = 0.68, p < 0.001) and total culturable fungi (r = 0.72, p < 0.001). Total (1 → 3)-β-D-glucan significantly correlated with Aspergillus/Penicillium, Alternaria, and Cladosporium. Alternaria and Botrytis were also found to highly correlate with (1 → 3)-β-D-glucan at the size <1 μm, which was less than the expected spore sizes (the mean measured aerodynamic sizes were 18.5 μm for Alternaria and 6.1 μm for Botrytis); therefore, Alternaria and Botrytis might release small fragments that could enter the deep lung and cause respiratory diseases.

Barrier disrupting effects of alternaria alternata extract on bronchial epithelium from asthmatic donors

Sensitization and exposure to the allergenic fungus Alternaria alternata has been associated with increased risk of asthma and asthma exacerbations. The first cells to encounter inhaled allergens are epithelial cells at the airway mucosal surface. Epithelial barrier function has previously been reported to be defective in asthma. This study investigated the contribution of proteases from Alternaria alternata on epithelial barrier function and inflammatory responses and compared responses of in vitro cultures of differentiated bronchial epithelial cells derived from severely asthmatic donors with those from non-asthmatic controls. Polarised 16HBE cells or air-liquid interface (ALI) bronchial epithelial cultures from non-asthmatic or severe asthmatic donors were challenged apically with extracts of Alternaria and changes in inflammatory cytokine release and transepithelial electrical resistance (TER) were measured. Protease activity in Alternaria extracts was characterised and the effect of selectively inhibiting protease activity on epithelial responses was examined using protease inhibitors and heat-treatment. In 16HBE cells, Alternaria extracts stimulated release of IL-8 and TNFα, with concomitant reduction in TER; these effects were prevented by heat-treatment of the extracts. Examination of the effects of protease inhibitors suggested that serine proteases were the predominant class of proteases mediating these effects. ALI cultures from asthmatic donors exhibited a reduced IL-8 response to Alternaria relative to those from healthy controls, while neither responded with increased thymic stromal lymphopoietin (TSLP) release. Only cultures from asthmatic donors were susceptible to the barrier-weakening effects of Alternaria. Therefore, the bronchial epithelium of severely asthmatic individuals may be more susceptible to the deleterious effects of Alternaria.

Correlation between fungal sIgE and bronchial asthma severity

Fungal sensitisation is closely associated with asthma; however, the correlation between fungi and asthma severity remains unclear. The aim of this study was to investigate the severity of asthma in 100 patients with asthma due to fungal and non-fungal allergens. A total of 100 outpatients and inpatients with asthma were selected from 2010 to 2011 and were divided into three groups (mild, moderate and severe) according to their clinical manifestations, lung function results and treatment situations. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of specific immunoglobulin E (sIgE) to five fungal allergens and seven non-fungal allergens in the serum of all patients. The levels of sIgE to Aspergillus, Penicillium and Candida albicans allergens in the severe group were significantly higher compared with those in the moderate and mild groups (P<0.001 and P<0.05, respectively); those of the moderate group were significantly higher compared with those of the mild group (P<0.05). No significant difference was observed for the levels of sIgE to Alternaria alternata among the three groups. sIgE to Cladosporium herbarum was not present for all three groups. No significant difference was observed for the levels of sIgE to non-fungal allergens among the three groups. Fungal allergens are closely correlated with the severity of asthma, whereas non-fungal allergens are not.

Airborne fungal cell fragments in homes in relation to total fungal biomass

Fungal exposure may induce respiratory symptoms. The causative agents are compounds in the fungal cell wall. Fragments of microbes may be present in air samples but are not measurable using conventional spore counting or by the determination of viable organisms. This study assesses the proportion of fungal cell biomass and endotoxin in different particle size fractions in air samples from homes. Air samples were collected from 15 homes using a cyclone sampler, collecting particles in three aerodynamic size fractions: <1.0, 1.0-1.8, and >1.8 μm. N-Acetylhexosaminidase (NAHA) was determined as a marker of fungal cell biomass. Endotoxin was determined using the Limulus amebocyte lysate method. NAHA and endotoxin in the size range <1.0 μm comprised up to 63% (mean 22.7%) and 96.3% (mean 22.6%) of the total concentrations, respectively. There were significant relationships between the amounts of NAHA and endotoxin in the total amount and in the size fraction >1.8 μm but not in the smaller fractions. The results demonstrate significant amounts of fungal cell biomass and endotoxin in particles <1.0 μm. Homes with reported mold damage had a lower concentration of NAHA in particles <1.0 μm than homes without mold damage. To assess airborne exposure for diagnostic and preventive purposes, measurement techniques that include this fraction should be considered.

World allergy organization study on aerobiology for creating first pollen and mold calendar with clinical significance in islamabad, pakistan;: a project of world allergy organization and pakistan allergy, asthma & clinical immunology centre of islamabad

Pollen and mold allergies are highly problematic in Islamabad. This study was conducted to investigate the type and concentration of airborne pollens/molds causing allergic diseases in susceptible individuals. A volumetric spore trap (Burkard) was placed at the height of 11 m and ran continuously for 3 years. Once a week, the collecting drum was prepared by affixing Melinex tape with a double sided adhesive that was coated with a thin layer of silicone grease. Every Sunday at 9:00 AM the drum was replaced by another drum and the pollen/mold spores were removed and permanently mounted on slides. Using a microscope, the trapped particles were identified and recorded as counts per cubic meter of air per hour. From these data, the pollen and mold calendars were constructed and expressed as counts per cubic meter of air per day. Skin prick tests were performed on more than 1000 patients attending the Pakistan Allergy, Asthma & Clinical Immunology Centre of Islamabad. The results indicated that there were 2 main pollen plants that contributed to seasonal allergies. These were Broussonetia papyrifera and Cannabis sativa during the March/April season and the July/September season, respectively. Although mold spores were continuously detected throughout the year, the most prominent mold was undetected mold and unconfirmed mold species similar to Stachybotrys species, which was high from July to September/October. Two additional molds contributing to allergic reactions were Pithomyces species and Cladosporium species, which were active during January and April, with the latter also being detected between October and November. These results may prove beneficial to both patients and physicians in planning a therapeutic protocol for avoidance and amelioration.