Spatial and temporal variations in airborne Ambrosia pollen in Europe.

The European Commission Cooperation in Science and Technology (COST) Action FA1203 "SMARTER" aims to make recommendations for the sustainable management of Ambrosia across Europe and for monitoring its efficiency and cost-effectiveness. The goal of the present study is to provide a baseline for spatial and temporal variations in airborne Ambrosia pollen in Europe that can be used for the management and evaluation of this noxious plant. The study covers the full range of Ambrosia artemisiifolia L. distribution over Europe (39°N-60°N; 2°W-45°E). Airborne Ambrosia pollen data for the principal flowering period of Ambrosia (August-September) recorded during a 10-year period (2004-2013) were obtained from 242 monitoring sites. The mean sum of daily average airborne Ambrosia pollen and the number of days that Ambrosia pollen was recorded in the air were analysed. The mean and standard deviation (SD) were calculated regardless of the number of years included in the study period, while trends are based on those time series with 8 or more years of data. Trends were considered significant at p < 0.05. There were few significant trends in the magnitude and frequency of atmospheric Ambrosia pollen (only 8% for the mean sum of daily average Ambrosia pollen concentrations and 14% for the mean number of days Ambrosia pollen were recorded in the air). The direction of any trends varied locally and reflected changes in sources of the pollen, either in size or in distance from the monitoring station. Pollen monitoring is important for providing an early warning of the expansion of this invasive and noxious plant.

The relationship between biomarkers of fungal allergy and lung damage in asthma.

BACKGROUND: Immunological biomarkers are the key to the diagnosis of allergic bronchopulmonary aspergillosis (ABPA) and fungal sensitisation, but how these relate to clinically relevant outcomes is unclear. OBJECTIVES: To assess how fungal immunological biomarkers are related to fixed airflow obstruction and radiological abnormalities in moderate to severe asthma. METHODS: Cross-sectional study of 431 asthmatics. Inflammatory biomarkers, lung function and an IgE fungal panel to colonising filamentous fungi, yeasts and fungal aeroallergens were measured. CT scans were scored for the presence of radiological abnormalities. Factor analysis informed the variables used in a k-means cluster analysis. Fixed airflow obstruction and radiological abnormalities were then mapped to these immunological variables in the cluster analysis. RESULTS: 329 (76.3%) subjects were sensitised to ≥ 1 fungi. Sensitisation to Aspergillus fumigatus and/or Penicillium chrysogenum was associated with a lower post-bronchodilator FEV1 compared with those not sensitised to fungi ((73.0 (95% CI 70.2-76) vs. 82.8 (95% CI 78.5-87.2)% predicted, P < 0.001), independent of atopic status (P = 0.005)), and an increased frequency of bronchiectasis (54.5%, P < 0.001), tree-in-bud (18.7%, P < 0.001) and collapse/consolidation (37.5%, P = 0.002). Cluster analysis identified three clusters: (i) hypereosinophilic (n = 71, 16.5%), (ii) high immunological biomarker load and high frequency of radiological abnormalities (n = 34, 7.9%) and (iii) low levels of fungal immunological biomarkers (n = 326, 75.6%). CONCLUSIONS AND CLINICAL RELEVANCE: IgE sensitisation to thermotolerant filamentous fungi, in particular A. fumigatus but not total IgE, is associated with fixed airflow obstruction and a number of radiological abnormalities in moderate to severe asthma. All patients with IgE sensitisation to A. fumigatus are at risk of lung damage irrespective of whether they meet the criteria for ABPA.

Allergic Fungal Airway Disease.

Fungi are ubiquitous and form their own kingdom. Up to 80 genera of fungi have been linked to type I allergic disease, and yet, commercial reagents to test for sensitization are available for relatively few species. In terms of asthma, it is important to distinguish between species unable to grow at body temperature and those that can (thermotolerant) and thereby have the potential to colonize the respiratory tract. The former, which include the commonly studied Alternaria and Cladosporium genera, can act as aeroallergens whose clinical effects are predictably related to exposure levels. In contrast, thermotolerant species, which include fungi from the Candida, Aspergillus, and Penicillium genera, can cause a persistent allergenic stimulus independent of their airborne concentrations. Moreover, their ability to germinate in the airways provides a more diverse allergenic stimulus, and may result in noninvasive infection, which enhances inflammation. The close association between IgE sensitization to thermotolerant filamentous fungi and fixed airflow obstruction, bronchiectasis, and lung fibrosis suggests a much more tissue-damaging process than that seen with aeroallergens. This review provides an overview of fungal allergens and the patterns of clinical disease associated with exposure. It clarifies the various terminologies associated with fungal allergy in asthma and makes the case for a new term (allergic fungal airway disease) to include all people with asthma at risk of developing lung damage as a result of their fungal allergy. Lastly, it discusses the management of fungirelated asthma.

Geographic and temporal variations in pollen exposure across Europe.

BACKGROUND: The EC-funded EuroPrevall project examined the prevalence of food allergy across Europe. A well-established factor in the occurrence of food allergy is primary sensitization to pollen. OBJECTIVE: To analyse geographic and temporal variations in pollen exposure, allowing the investigation of how these variations influence the prevalence and incidence of food allergies across Europe. METHODS: Airborne pollen data for two decades (1990-2009) were obtained from 13 monitoring sites located as close as possible to the EuroPrevall survey centres. Start dates, intensity and duration of Betulaceae, Oleaceae, Poaceae and Asteraceae pollen seasons were examined. Mean, slope of the regression, probability level (P) and dominant taxa (%) were calculated. Trends were considered significant at P < 0.05. RESULTS: On a European scale, Betulaceae, in particular Betula, is the most dominant pollen exposure, two folds higher than to Poaceae, and greater than five folds higher than to Oleaceae and Asteraceae. Only in Reykjavik, Madrid and Derby was Poaceae the dominant pollen, as was Oleaceae in Thessaloniki. Weed pollen (Asteraceae) was never dominant, exposure accounted for >10% of total pollen exposure only in Siauliai (Artemisia) and Legnano (Ambrosia). Consistent trends towards changing intensity or duration of exposure were not observed, possibly with the exception of (not significant) decreased exposure to Artemisia and increased exposure to Ambrosia. CONCLUSIONS: This is the first comprehensive study quantifying exposure to the major allergenic pollen families Betulaceae, Oleaceae, Poaceae and Asteraceae across Europe. These data can now be used for studies into patterns of sensitization and allergy to pollen and foods.

Isolation of Aspergillus fumigatus from sputum is associated with elevated airborne levels in homes of patients with asthma.

Indoor bioaerosols, such as mold spores, have been associated with respiratory symptoms in patients with asthma; however, dose-response relationships and guidelines on acceptable levels are lacking. Furthermore, a causal link between mold exposure and respiratory infections or asthma remains to be established. The aim of this study was to determine indoor concentrations of Aspergillus fumigatus and a subset of clinically relevant fungi in homes of people with asthma, in relation to markers of airways colonization and sensitization. Air and dust samples were collected from the living room of 58 properties. Fungal concentrations were quantified using mold-specific quantitative PCR and compared with traditional microscopic analysis of air samples. Isolation of A. fumigatus from sputum was associated with higher airborne concentrations of the fungus in patient homes (P = 0.04), and a similar trend was shown with Aspergillus/Penicillium-type concentrations analyzed by microscopy (P = 0.058). No association was found between airborne levels of A. fumigatus and sensitization to this fungus, or dustborne levels of A. fumigatus and either isolation from sputum or sensitization. The results of this study suggest that the home environment should be considered as a potential source of fungal exposure, and elevated home levels may predispose people with asthma to airways colonization.

Isolation of filamentous fungi from sputum in asthma is associated with reduced post-bronchodilator FEV1.

BACKGROUND: Fungal sensitization is common in severe asthma, but the clinical relevance of this and the relationship with airway colonization by fungi remain unclear. The range of fungi that may colonize the airways in asthma is unknown. OBJECTIVE: To provide a comprehensive analysis on the range of filamentous fungi isolated in sputum from people with asthma and report the relationship with their clinico-immunological features of their disease. METHODS: We recruited 126 subjects with a diagnosis of asthma, 94% with moderate-severe disease, and 18 healthy volunteers. At a single stable visit, subjects underwent spirometry; sputum fungal culture and a sputum cell differential count; skin prick testing to both common aeroallergens and an extended fungal panel; specific IgE to Aspergillus fumigatus. Fungi were identified by morphology and species identity was confirmed by sequencing. Four patients had allergic bronchopulmonary aspergillosis. RESULTS: Forty-eight percent of asthma subjects were IgE-sensitized to one fungal allergen and 22% to ≥ 2. Twenty-seven different taxa of filamentous fungi were isolated from 54% of their sputa, more than one species being detected in 17%. This compared with 3 (17%) healthy controls culturing any fungus (P < 0.01). Aspergillus species were most frequently cultured in isolation followed by Penicillium species. Post-bronchodilator FEV (1) (% predicted) in the subjects with asthma was 71(± 25) in those with a positive fungal culture vs. 83 (± 25) in those culture-negative, (P < 0.01). CONCLUSION AND CLINICAL RELEVANCE: Numerous thermotolerant fungi other than A. fumigatus can be cultured from sputum of people with moderate-to-severe asthma; a positive culture is associated with an impaired post-bronchodilator FEV (1) , which might be partly responsible for the development of fixed airflow obstruction in asthma. Sensitization to these fungi is also common.

Guidelines on ambient intramural airborne fungal spores.

OBJECTIVES: To generate baseline data for indoor airborne fungal spores in noncomplaint residential properties (with no moisture/mold-related problems) and to identify home characteristics indicative of elevated fungal levels. METHODS: Air samples were collected onto petroleum jelly-coated slides from living rooms of 100 residential properties in Leicestershire, United Kingdom, using a Burkard continuous recording air sampler. The slides were examined by microscopy to determine fungal spore concentrations (spores/m3 air/day). RESULTS: Total indoor fungal spore concentrations were approximately 16% of outdoor concentrations. Abundant indoor fungal genera include Cladosporium, Sporobolomyces, Tilletiopsis, and Didymella, all of which followed seasonal patterns of release and detection. No clear association was shown between outdoor-predominant fungi and home characteristics. In contrast, Aspergillus/Penicillium-type (Asp/ Pen-type) spores were common indoors and exceeded outdoor levels, with the highest concentrations detected in properties over 90 years old (P = .006) and terraced properties (P = .003). CONCLUSION: Asp/Pen-type spores are found in noncomplaint UK residential properties and mostly in old terraced houses. This study provides guidelines on acceptable levels of Asp/Pen-type spores and other abundant indoor fungal taxa that can be comparatively used in clinical evaluations of fungal exposure-related disease.

High genetic diversity in a rare and endangered sunflower as compared to a common congener.

Determining the genetic structure of isolated or fragmented species is of critical importance when planning a suitable conservation strategy. In this study, we use nuclear and chloroplast SSRs (simple sequence repeats) to investigate the population genetics of an extremely rare sunflower, Helianthus verticillatus Small, which is known from only three locations in North America. We investigated levels of genetic diversity and population structure compared to a more common congener, Helianthus angustifolius L., using both nuclear and chloroplast SSRs. We also investigated its proposed hybrid origin from Helianthus grosseserratus Martens and H. angustifolius. Twenty-two nuclear SSRs originating from the cultivated sunflower (Helianthus annuus L.) expressed sequence tag (EST) database, and known to be transferable to H. verticillatus and its putative parental taxa, were used in this study thereby allowing for statistical control of locus-specific effects in population genetic analyses. Despite its rarity, H. verticillatus possessed significantly higher levels of genetic diversity than H. angustifolius at nuclear loci and equivalent levels of chloroplast diversity. Significant levels of population subdivision were observed in H. verticillatus but of a magnitude comparable to that of H. angustifolius. Inspection of multilocus genotypes also revealed that clonal spread is highly localized. Finally, we conclude that H. verticillatus is not of hybrid origin as it does not exhibit a mixture of parental alleles at nuclear loci, and it does not share a chloroplast DNA haplotype with either of its putative parents.