Multiplex protein profiling of bronchoalveolar lavage in idiopathic pulmonary fibrosis and hypersensitivity pneumonitis

Context: Idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis (HP) are diffuse parenchymal lung diseases characterized by a mixture of inflammation and fibrosis, leading to lung destruction and finally death. AIMS: The aim of this study was to compare different pathophysiological mechanisms, such as angiogenesis, coagulation, fibrosis, tissue repair, inflammation, epithelial damage, oxidative stress, and matrix remodeling, in both disorders using bronchoalveolar lavage (BAL). Methods: At diagnosis, patients underwent bronchoscopy with BAL and were divided into three groups: Control ( n = 10), HP ( n = 11), and IPF ( n = 11), based on multidisciplinary approach (clinical examination, radiology, and histology): Multiplex searchlight technology was used to analyze 25 proteins representative for different pathophysiological processes: Eotaxin, basic fibroblast growth factor (FGFb), fibronectin, hepatocyte growth factor (HGF), interleukine (IL)-8, IL-12p40, IL-17, IL-23, monocyte chemotactic protein (MCP-1), macrophage-derived chemokine (MDC), myeloperoxidase (MPO), matrix metalloproteinase (MMP)-8, MMP-9, active plasminogen activating inhibitor 1 (PAI-1), pulmonary activation regulated chemokine (PARC), placental growth factor (PlGF), protein-C, receptor for advanced glycation end products (RAGE), regulated on activation normal T cells expressed and secreted (RANTES), surfactant protein-C (SP-C), transforming growth factor-β1 (TGF-β1), tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue factor, thymic stromal lymphopoietin (TSLP), and vascular endothelial growth factor (VEGF). Results: All patients suffered from decreased pulmonary function and abnormal BAL cell differential compared with control. Protein levels were increased in both IPF and HP for MMP-8 ( P = 0.022), MMP-9 ( P = 0.0020), MCP-1 ( P = 0.0006), MDC ( P = 0.0048), IL-8 ( P = 0.013), MPO ( P = 0.019), and protein-C ( P = 0.0087), whereas VEGF was decreased ( P = 0.0003) compared with control. HGF was upregulated in HP ( P = 0.0089) and active PAI-1 was upregulated ( P = 0.019) in IPF compared with control. Differences in expression between IPF and HP were observed for IL-12p40 ( P = 0.0093) and TGF-β1 ( P = 0.0045). Conclusions: Using BAL, we demonstrated not only expected similarities but also important differences in both disorders, many related to the innate immunity. These findings provide new clues for further research in both disorders

Residential green space and mental health in a prospective cohort of tree pollen allergy patients

BACKGROUND: Green space may improve human health, for example by promoting physical activity and by reducing stress. Conversely, green space may exacerbate the burden of allergic disease by emitting aeroallergens. OBJECTIVES: We examined whether residential exposure to green space had impacts on mental health in adults sensitized to tree pollen allergens during two airborne tree pollen seasons (2017, 2018). METHODS: In this cross-sectional study, data from a prospective Belgian cohort of tree pollen allergy patients (N = 88) were analyzed using Poisson regression. The primary outcome was self-reported mental health, assessed with the standardized 12-item General Health Questionnaire (GHQ-12). Predictors of distress included perceived presence of allergenic trees near the residence (hazel, alder, birch) and cumulative green space area within 1 km distance. Results were compared to distress in a representative sample of the general population (N = 2,467). RESULTS: Short-term distress [mean GHQ-12 score 2.1 (95% confidence interval 1.5–2.7)] was higher in the study population than in the general population [1.5 (1.4–1.7)]. Distress increased with BMI {adjusted odds ratio [95% confidence interval] 1.06 (1.02–1.10)}, smoking [2.10 (1.02–4.38)] and perceived presence of allergenic trees [2.04 (1.36–3.07)]. Physical activity [>1×/week 20 minutes of activity vs. less: 0.59 (0.42–0.85)], age [0.97 (0.96–0.99)] and green space [≥ 3m tall, per combined surface area of 10 ha: 0.94 (0.90–0.99); < 3m tall, per 10 ha: 0.85 (0.78–0.93)] had protective effects against short-term distress. CONCLUSIONS: The perceived proximity to allergenic tree species modulates the protective effect of residential green space against short-term emotional distress during the airborne pollen season. Negative expectations of adults sensitized to tree pollen allergens regarding exposure to allergenic tree species may affect short-term mental health outcomes during the pollen season.status: publishe

An evaluation of species distribution models to estimate tree diversity at genus level in a heterogeneous urban-rural landscape

Trees provide ecosystem services that improve the environment and human health. The magnitude of these improvements may be related to tree diversity within green spaces, yet spatially explicit diversity data necessary to investigate such associations are often missing. Here, we evaluate two methods to model tree diversity at genus level based on environmental covariates and presence point data. We want to identify the drivers and suitable methods for urban and rural tree diversity models in the heterogeneous region of Flanders, Belgium. We stratified our research area into dominantly rural and dominantly urban areas and developed distribution models for 13 tree genera for both strata as well as for the area as a whole. Occurrence data were obtained from an open-access presence-only database of validated observations of vascular plants. These occurrence data are combined with environmental covariates in MaxEnt models. Tree diversity is modelled by adding up the individual species distribution models. Models in the dominantly rural areas are driven by soil characteristics (soil texture and drainage class). Models in the dominantly urban areas are driven by environmental covariates explaining urban heterogeneity. Nevertheless, the stratification into urban and rural did not contribute to a higher model quality. Generic tree diversity estimates were better when presences derived from distribution models were simply added up (binary stacking, True Positive Rate of 0.903). The application of macro-ecological constraints resulted in an underestimation of generic tree diversity (probability stacking, True Positive Rate of 0.533). We conclude that summing presences derived from species distribution models (binary stacking) is a suitable approach to increase knowledge on regional diversity.status: Published onlin

Association between local airborne tree pollen composition and surrounding land cover across different spatial scales in Northern Belgium

Airborne pollen are important&nbsp;aeroallergens&nbsp;affecting human health. Local airborne pollen compositions can pose health-risks for the sensitized population, but at present little is known about fine-scale pollen composition&nbsp;patterns. The overall objective of this study is to determine local variations in tree pollen composition with passive samplers and to identify the surrounding landscape characteristics that drive them. In February–May 2017, during the tree pollen season, airborne tree pollen were measured by passive sampling at 2 m height above ground-level in 14 sites in the Flanders and Brussels-Capital region (Belgium). Non-metric&nbsp;multidimensional scaling&nbsp;was used to investigate&nbsp;environmental gradients&nbsp;that determine the pollen composition and amounts. Land cover types were identified across spatial scales ranging between 20 m and 5&nbsp;km. The passive samplers detected the same pollen taxa during the same time windows as the validated volumetric Burkard samplers. Using passive samplers, we were able to measure local airborne pollen compositions.&nbsp;Corylus&nbsp;and&nbsp;Platanus&nbsp;pollen were associated to urban areas;&nbsp;Populus, Juglans&nbsp;and&nbsp;Fraxinus&nbsp;pollen to agricultural areas; forests and wetlands were sources of&nbsp;Alnus&nbsp;and&nbsp;Quercus&nbsp;pollen.&nbsp;Salix, Populus&nbsp;and&nbsp;Betula&nbsp;pollen were also mainly associated to wetlands. The landscape context drives the airborne tree pollen composition at a meso-scale (1−5 km) rather than at finer scale (20−500 m). Thus, land cover types (e.g. forest, bush land, agricultural lands and wetlands) surrounding urban areas may increase exposure to allergenic pollen in the urban area, potentially affecting the health of a large proportion of the&nbsp;population.</p

Silicone wristband passive samplers yield highly individualized pesticide residue exposure profiles

Monitoring human exposure to pesticides and pesticide residues (PRs) remains crucial for informing public health policies, despite strict regulation of plant protection product and biocide use. We used 72 low-cost silicone wristbands as non-invasive passive samplers to assess cumulative 5-day exposure of 30 individuals to polar PRs. Ethyl acetate extraction and LC-MS/MS analysis were used for the identification of PRs. Thirty-one PRs were detected of which 15 PRs (48%) were detected only in worn wristbands, not in environmental controls. The PRs included 16 fungicides (52%), 8 insecticides (26%), 2 herbicides (6%), 3 pesticide derivatives (10%), 1 insect repellent (3%) and 1 pesticide synergist (3%). Five detected pesticides were not approved for plant protection use in the EU. Smoking and dietary habits that favor vegetable consumption were associated to higher numbers and higher cumulative concentrations of PRs in wristbands. Wristbands featured unique PR combinations. Our results suggest both environment and diet contributed to PR exposure in our study group. Silicone wristbands could serve as sensitive passive samplers to screen population-wide cumulative dietary and environmental exposure to authorized, unauthorized and banned pesticides.This research has been reviewed and approved by the ethical review board SMEC of the University of Leuven (protocol number G-2016 09 636).status: publishe

Predicting allergenic tree species distributions from the Belgian soil map and a gridded presence database of vascular plants

Tree pollen are a major source of aeroallergens which trigger allergic reactions in sensitized people. Climate change increases the burden of tree-related allergic diseases as higher temperatures and changes in precipitation patterns increase the duration and intensity of pollination of allergenic tree species such as birch (Betula spp.). Information on the distribution of allergenic tree species may be helpful to quantify the potential exposure to tree allergens but to date such detailed species distribution maps are lacking. To address this issue, we modelled the probability of occurrence of the thirteen most prominent allergenic tree species in Flanders. We used maximum entropy modelling to calculate probabilities of tree species occurrence based on presence-only data sourced from an open access databank of plant species distributions in Flanders and environmental variables related to the potential natural distribution of tree species in Flanders. Soil texture was used as a proxy for soil fertility and soil drainage class as a proxy for soil moisture. Both variables were derived from the Belgian Soil Map resampled to 1×1 km grid cells. We used landscape types from the Biological Valuation Map and average lowest and highest ground water from Ecoplan as additional environmental predictor variables. Species distribution models were more meaningful than a random distribution for all thirteen allergenic tree species. The Area Under Curve (AUC) varied between 0.53 for Salix and 0.92 for Platanus. Texture class and drainage class were consequently among the most important variables contributing to the models. Probabilities of occurrence were converted to distribution maps using varying expert-based thresholds for the different allergenic tree species. A combined alpha diversity map of allergenic tree species shows hotspots of allergenic tree species diversity in the Campine region and a lower diversity in more industrialised or agriculture dominated parts of Flanders.status: publishe

Residential green space and medication sales for childhood asthma: a longitudinal ecological study in Belgium

Background: Living in green environments has been associated with various health benefits, but the evidence for positive effects on respiratory health in children is ambiguous. Objective: To investigate if residential exposure to different types of green space is associated with childhood asthma prevalence in Belgium. Methods: Asthma prevalence was estimated from sales data of reimbursed medication for obstructive airway disease (OAD) prescribed to children between 2010 and 2014, aggregated at census tract level (n = 1872) by sex and age group (6–12 and 13–18 years). Generalized log-linear mixed effects models with repeated measures were used to estimate effects of relative covers of forest, grassland and garden in the census tract of the residence on OAD medication sales. Models were adjusted for air pollution (PM10), housing quality and administrative region. Results: Consistent associations between OAD medication sales and relative covers of grassland and garden were observed (unadjusted parameter estimates per IQR increase of relative cover, range across four strata: grassland, β = 0.15–0.17; garden, β = 0.13–0.17). The associations remained significant after adjusting for housing quality and chronic air pollution (adjusted parameter estimates per IQR increase of relative cover, range across four strata: grassland, β = 0.10–0.14; garden, β = 0.07–0.09). There was no association between OAD medication sales and forest cover. Conclusions: Based on aggregated data, we found that living in close proximity to areas with high grass cover (grasslands, but also residential gardens) may negatively impact child respiratory health. Potential allergic and non-allergic mechanisms that underlie this association include elevated exposure to grass pollen and fungi and reduced exposure to environmental biodiversity. Reducing the dominance of grass in public and private green space might be beneficial to reduce the childhood asthma burden and may simultaneously improve the ecological value of urban green space.All health data were anonymized by aggregation to census tract level and were used under license of IMA-AIM. The protocol for this study did not require ethics approval.status: publishe