[A multi-dimensional analysis of pollen broadcasting concerns in Chinese population: a large-scale multi-center cross-sectional survey]

Objective: To investigate the concern about pollen broadcasting in Chinese population from multiple dimensions and to understand the information about allergic rhinitis (AR) in China by analyzing related factors. Methods: From March 1 to September 30, 2022, a large-scale multi-center cross-sectional survey was conducted based on the Questionnaire Star platform in 21 Chinese hospitals. A total of 7 056 subjects from 7 regions in China: Northeast, North, East, Central, South, Southwest, and Northwest China were included. Basic characteristics (including social demographic characteristics and disease characteristics of AR patients), concern about pollen broadcasting, the willingness of pollen-induced AR (PiAR) patients to receive pollen broadcasting, and the treatment satisfaction rate of AR patients were collected. The chi-square test, multivariate linear regression model, and Logistic regression analysis were used to analyze the concern about pollen broadcasting in the Chinese population and related factors from multiple dimensions. Results: Among 7 056 subjects, 23.02% were concerned about pollen broadcasting. Among 3 176 self-reported AR and 1 019 PiAR patients, 25.60% and 39.16% were concerned about pollen broadcasting, respectively, which was higher than that of non-AR or non-PiAR subjects (χ2 value was 21.74 and 175.11, respectively, both P<0.001). Among AR patients, the proportion of spring and autumn allergen-positive patients concerned about pollen broadcasting was higher than that in perennial allergen-positive patients (χ2 value was 20.90 and 19.51, respectively, both P<0.001). The proportion of AR patients with asthma, sinusitis, allergic conjunctivitis, and cardiovascular and cerebrovascular diseases was higher than those without complications (χ2 value was 50.83, 21.97, 56.78, 7.62, respectively, all P<0.05). The proportion of AR patients in North China who could find pollen broadcasting locally was 31.01%, significantly higher than those in other regions (all P<0.05). Multivariate linear regression model analysis showed that among PiAR patients, those with higher per capita household income and higher AR disease cognition levels had been concerned about pollen broadcasting in the past, and those complicated with allergic conjunctivitis had stronger intention to receive pollen broadcasting (B value was 0.24, 0.13, 0.66, 0.47, respectively, all P<0.05). The higher the disease cognition level of PiAR patients, the stronger their willingness to actively participate in treatment (R2=0.72, P<0.001). Only 18.89% of AR patients felt satisfied with the treatment effect. Logistic regression analysis showed that in AR patients, the treatment satisfaction rate was significantly higher among those concerned about pollen broadcasting compared to those who were not (OR=1.83, P<0.001). Conclusions: Currently, the dissemination of pollen broadcasting in China is hindered by various factors such as disease cognition level. The treatment satisfaction among AR patients remains unsatisfactory.

Effects of pollen concentration on allergic rhinitis in children: A retrospective study from Beijing, a Chinese megacity

With global climate change and rapid urbanization, the prevalence of allergic diseases caused by pollen is rising dramatically worldwide with unprecedented complexity and severity, especially for children in mega-cities. However, because of the lack of long time-series pollen concentrations data, the accurate evaluation of the impact of pollen on allergic rhinitis (AR) was scarce in the Chinese metropolis. A generalized additive model was used to assess the effect of pollen concentration on pediatric AR outpatient visits in Beijing from 2014 to 2019. A stratified analysis of 10 pollen species and age-gender-specific groups was also conducted during the spring and summer-autumn peak pollen periods separately. Positive associations between pollen concentration and pediatric AR varied with the season and pollen species were detected. Although the average daily pollen concentration is higher during the spring tree pollen peak, the influence was stronger at the summer-autumn weed pollen peak with the maximum relative risk 1.010 (95% CI 1.009, 1.011), which was higher than the greatest relative risk, 1.003 (95% CI 1.002, 1.004) in the spring peak. The significant adverse effects can be sustained to lag10 during the study period, and longer in the summer-autumn peak (lag13) than in the spring peak (lag8). There are thresholds for the health effects and they varied between seasons. The significant effect appeared when the pollen concentration was higher than 3.74 × 105 grain·m-2·d-1 during the spring tree pollen peaks and 4.70 × 104 grain·m-2·d-1 during the summer-autumn weed pollen peaks. The stratified results suggested that the species-specific effects were heterogeneous. It further highlights that enough attention should be paid to the problem of pollen allergy in children, especially school-aged children aged 7-18 years and weed pollen in the summer-autumn peak pollen period. These findings provide a more accurate reference for the rational coordination of medical resources and improvement of public health.

Mechanistic insights into silica nanoparticle-allergen interactions on antigen presenting cell function in the context of allergic reactions

The incorporation of nanomaterials into consumer products has substantially increased in recent years, raising concerns about their safety. The inherent physicochemical properties of nanoparticles allow them to cross epithelial barriers and gain access to immunocompetent cells. Nanoparticles in cosmetic products can potentially interact with environmental allergens, forming a protein corona, and together penetrate through damaged skin. Allergen-nanoparticle interactions may influence the immune response, eventually resulting in an adverse or beneficial outcome in terms of allergic reactivity. This study determines the impact of silica nanoparticle-allergen interactions on allergic sensitization by studying the major molecular mechanisms affecting allergic responses. The major birch pollen allergen Bet v 1 was chosen as a model allergen and the birch pollen extract as a comparator. Key events in immunotoxicity including allergen uptake, processing, presentation, expression of costimulatory molecules and cytokine release were studied in human monocyte-derived dendritic cells. Using an in vivo sensitization model, murine Bet v 1-specific IgG and IgE levels were monitored. Upon the interaction of allergens with silica nanoparticles, we observed an enhanced uptake of the allergen by macropinocytosis, improved proteolytic processing, and presentation concomitant with a propensity to increase allergen-specific IgG2a and decrease IgE antibody levels. Together, these events suggest that upon nanoparticle interactions the immune response is biased towards a type 1 inflammatory profile, characterized by the upregulation of T helper 1 (Th1) cells. In conclusion, the interaction of the birch pollen allergen with silica nanoparticles will not worsen allergic sensitization, a state of type 2-inflammation, but rather seems to decrease it by skewing towards a Th1-dominated immune response.

The Role of Climate Change in Asthma

Human activity and increased use of fossil fuels have led to climate change. These changes are adversely affecting human health, including increasing the risk of developing asthma. Global temperatures are predicted to increase in the future. In 2019, asthma affected an estimated 262 million people and caused 455,000 deaths. These rates are expected to increase. Climate change by intensifying climate events such as drought, flooding, wildfires, sand storms, and thunderstorms has led to increases in air pollution, pollen season length, pollen and mold concentration, and allergenicity of pollen. These effects bear implications for the onset, exacerbation, and management of childhood asthma and are increasing health inequities. Global efforts to mitigate the effects of climate change are urgently needed with the goal of limiting global warming to between 1.5 and 2.0 °C of preindustrial times as per the 2015 Paris Agreement. Clinicians need to take an active role in these efforts in order to prevent further increases in asthma prevalence. There is a role for clinician advocacy in both the clinical setting as well as in local, regional, and national settings to install measures to control and curb the escalating disease burden of childhood asthma in the setting of climate change.

Higher Risk for Sensitization to Commonly Consumed Herbs among Adults and Youngsters Suffering from Birch, Mugwort or Grass Pollinosis

Background: According to recent findings, mugwort and birch pollen-allergic patients represent a high-risk group for developing adverse allergic reactions to herbal spices due to cross-reacting allergens found in both pollen and raw herbs. Such associations are known as a pollen-plant food allergy syndrome. Objective: The aim of the study was to evaluate the extent of sensitization to commonly consumed herb species representing Lamiaceae, Apiaceae and Brassicaceae families in Polish patients with suspected birch, mugwort or grass pollen allergy. Materials and Methods: Data were obtained from 180 patients, adults and children with suspected allergy to aeroallergens. Skin prick tests (SPT) were performed with standard birch, mugwort, grass mixture or dust mite extracts. Prick by prick tests were performed with fresh extracts of popular herbs: basil, oregano, lemon balm, mint, salvia, rosemary, thyme, anise, caraway and mustard. Results: Twenty-nine percent of patients were characterized by concomitant positive skin prick reactions to both herbs and pollens extracts. The concomitant pollinosis significantly increased the risk of SPT reaction to all tested herbs in adults (odds ratio, OR = 2.15−7.35) and children (OR = 5.3−28). The extent of SPT responses to herbs from Lamiaceae + Apiaceae were strongly correlated with SPT responses to pollens in the pediatric group (r = 0.685/p < 0.001). Conclusion: The study demonstrates that youngsters suffering from pollinosis are at high risk of developing allergic reactions to herbs and highlights the importance of including native skin prick tests with herbs in the diagnostic work-up for suspected food allergy.

Association between grass, tree and weed pollen and asthma health outcomes in Adelaide, South Australia: a time series regression analysis

OBJECTIVES

We aim to establish daily risk estimates of the relationships between grass, tree and weed pollen and asthma health outcomes.

DESIGN

Time series regression analysis of exposure and health outcomes using interaction by month to determine risk estimates all year round.

SETTING

Metropolitan Adelaide, South Australia.

PARTICIPANTS

Health outcomes for asthma are based on 15 years of hospital admissions, 13 years emergency presentations and ambulance callouts. In adults (≥18 years), there were 10 381 hospitalisations, 26 098 emergency department (ED) presentations and 11 799 ambulance callouts and in children (0-17 years), 22 114, 39 813 and 3774, respectively.

OUTCOME MEASURES

The cumulative effect of 7 day lags was calculated as the sum of the coefficients and reported as incidence rate ratio (IRR) related to an increase in 10 grains of pollen/m³.

RESULTS

In relation to grass pollen, children and adults were disparate in their timing of health effects. Asthma outcomes in children were positively related to grass pollen in May, and for adults in October. Positive associations with weed pollen in children was seen from February to May across all health outcomes. For adults, weed pollen-related health outcomes were restricted to February. Adults were not affected by tree pollen, while children's asthma morbidity was associated with tree pollen in August and September. In children, IRRs ranged from 1.14 (95% CI 1.06 to 1.21) for ED presentations for tree pollen in August to 1.98 (95% CI 1.06 to 3.72) for weed pollen in February. In adults, IRRs ranged from 1.28 (95% CI 1.01 to 1.62) for weed pollen in February to 1.31 (95% CI 1.08 to 1.57) for grass pollen in October.

CONCLUSION

Monthly risk assessment indicated that most pollen-related asthma health outcomes in children occur in the colder part of the year, while adults are affected in the warm season. The findings indicate a need for year-round pollen monitoring and related health campaigns to provide effective public health prevention.

Birch pollen, air pollution and their interactive effects on airway symptoms and peak expiratory flow in allergic asthma during pollen season - a panel study in Northern and Southern Sweden

BACKGROUND

Evidence of the role of interactions between air pollution and pollen exposure in subjects with allergic asthma is limited and need further exploration to promote adequate preventive measures. The objective of this study was to assess effects of exposure to ambient air pollution and birch pollen on exacerbation of respiratory symptoms in subjects with asthma and allergy to birch.

METHODS

Thirty-seven subjects from two Swedish cities (Gothenburg and Umeå) with large variation in exposure to both birch-pollen and air pollutants, participated in the study. All subjects had confirmed allergy to birch and self-reported physician-diagnosed asthma. The subjects recorded respiratory symptoms such as rhinitis or eye irritation, dry cough, dyspnoea, the use of any asthma or allergy medication and peak respiratory flow (PEF), daily for five consecutive weeks during two separate pollen seasons and a control season without pollen. Nitrogen oxides (NO_x), ozone (O₃), particulate matter (PM_2.5), birch pollen counts, and meteorological data were obtained from an urban background monitoring stations in the study city centres. The data were analysed using linear mixed effects models.

RESULTS

During pollen seasons all symptoms and medication use were higher, and PEF was reduced in the subjects. In regression analysis, exposure to pollen at lags 0 to 2 days, and lags 0 to 6 days was associated with increased ORs of symptoms and decreased RRs for PEF. Pollen and air pollution interacted in some cases; during low pollen exposure, there were no associations between air pollution and symptoms, but during high pollen exposure, O₃ concentrations were associated with increased OR of rhinitis or eye irritation, and PM_2.5 concentrations were associated with increased ORs of rhinitis or eye irritation, dyspnea and increased use of allergy medication.

CONCLUSIONS

Pollen and air pollutants interacted to increase the effect of air pollution on respiratory symptoms in allergic asthma. Implementing the results from this study, advisories for individuals with allergic asthma could be improved, minimizing the morbidities associated with the condition.

Thunderstorm asthma: a review, risks for Aotearoa New Zealand, and health emergency management considerations

AIM

To provide an up-to-date review of thunderstorm asthma (TA), identifying causative factors, and to discuss implications for management of TA in New Zealand.

METHODS

A literature search was carried out to identify articles that investigate the characteristics and causative factors of TA. Nine electronic databases were searched, yielding 372 articles, reduced to 30 articles after screening for duplication and relevance.

RESULTS

TA is globally rare, with 29 reported events since 1983, but is expected to increase in frequency as Earth warms. Triggers include both pollen (particularly ryegrass pollen) and fungal spores. Individual risk factors include outdoor exposure, sensitivity to triggering allergens and history of seasonal allergic rhinitis. History of asthma is not a strong risk factor but is associated with severity of outcome. Limited data on demographic characteristics suggests that individuals aged between 20 and 60 and (in Australasia) of Asian/Indian ethnicity are at higher risk. A single TA event has been reported in New Zealand to date, but much of New Zealand may be at risk of future events given that ryegrass pastures are widely distributed, and summer thunderstorms can occur anywhere.

CONCLUSIONS

We recommend developing rapidly deployable public messaging to support the health emergency management response to future TA events, together with the instigation of routine aeroallergen monitoring.

A Review of the Respiratory Health Burden Attributable to Short-Term Exposure to Pollen

Respiratory diseases such as asthma, allergic rhinitis (AR) and chronic obstructive pulmonary disease (COPD) affect millions worldwide and pose a significant global public health burden. Over the years, changes in land use and climate have increased pollen quantity, allergenicity and duration of the pollen season, thus increasing its impact on respiratory disease. Many studies have investigated the associations between short-term ambient pollen (i.e., within days or weeks of exposure) and respiratory outcomes. Here, we reviewed the current evidence on the association between short-term outdoor pollen exposure and thunderstorm asthma (TA), asthma and COPD hospital presentations, general practice (GP) consultations, self-reported respiratory symptoms, lung function changes and their potential effect modifiers. The literature suggests strong evidence of an association between ambient pollen concentrations and almost all respiratory outcomes mentioned above, especially in people with pre-existing respiratory diseases. However, the evidence on sub-clinical lung function changes, COPD, and effect modifiers other than asthma, hay fever and pollen sensitisation are still scarce and requires further exploration. Better understanding of the implications of pollen on respiratory health can aid healthcare professionals to implement appropriate management strategies.

Prophylactic and Therapeutic Effects of Oral Immunotherapy on Birch Pollen-Induced Allergic Conjunctivitis in Mice with a Rice-Based Edible Vaccine Expressing a Hypoallergenic Birch Pollen Allergen

We investigated the prophylactic and therapeutic effects of the oral administration of transgenic rice seeds expressing a hypoallergenic Bet v 1 derivative of allergic birch pollen conjunctivitis in mice. Transgenic rice seed depositing a chimeric molecule called TPC7 (tree pollen chimera 7) created by DNA shuffling of Bet v 1 family sequences from birch, alder and hazel in protein bodies of endosperm was generated. BALB/c mice were sensitized to birch pollen in alum and challenged with pollen in eyedrops. They were fed TPC7 transgenic or non-transgenic (control) rice seeds for 14 d before sensitization (prophylactic protocol) or 17 d after sensitization (therapeutic protocol). The clinical score and number of conjunctival eosinophils were significantly lower in TPC7-fed mice than in the control mice based on both the prophylactic and therapeutic protocols. Serum concentration of allergen-specific IgE did not differ between TPC7-fed and control groups in either protocol. Prophylactic administration of TPC7 downregulated the production of IL-4 and IFN-γ, whereas therapeutic administration of TPC7 upregulated the production of IFN-γ by allergen-stimulated splenocytes. Prophylactic or therapeutic oral administration of transgenic rice expressing TPC7 suppressed birch pollen-induced allergic conjunctivitis in mice. Feeding transgenic rice is a potentially effective approach as an allergen-specific immunotherapy for allergic conjunctivitis.

Dosing intact birch pollen grains at the air-liquid interface (ALI) to the immortalized human bronchial epithelial cell line BEAS-2B

In real life, humans are exposed to whole pollen grains at the air epithelial barrier. We developed a system for in vitro dosing of whole pollen grains at the Air-Liquid Interface (ALI) and studied their effect on the immortalized human bronchial epithelial cell line BEAS-2B. Pollen are sticky and large particles. Dosing pollen needs resuspension of single particles rather than clusters, and subsequent transportation to the cells with little loss to the walls of the instrumentation i.e. in a straight line. To avoid high speed impacting insults to cells we chose sedimentation by gravity as a delivery step. Pollen was resuspended into single particles by pressured air. A pollen dispersion unit including PTFE coating of the walls and reduced air pressure limited impaction loss to the walls. The loss of pollen to the system was still about 40%. A linear dose effect curve resulted in 327-2834 pollen/cm2 (± 6.1%), the latter concentration being calculated as the amount deposited on epithelial cells on high pollen days. After whole pollen exposure, the largest differential gene expression at the transcriptomic level was late, about 7 hours after exposure. Inflammatory and response to stimulus related genes were up-regulated. We developed a whole pollen exposure air-liquid interface system (Pollen-ALI), in which cells can be gently and reliably dosed.

Alteration of lung tissues proteins in birch pollen induced asthma mice before and after SCIT

Subcutaneous immunotherapy (SCIT) is a classic form of allergen-specific immunotherapy that is used to treat birch pollen induced allergic asthma. To investigate the underlying molecular mechanisms of SCIT, we aimed to profile lung samples to explore changes in the differential proteome before and after SCIT in mice with allergic asthma. Fresh lungs were collected from three groups of female BALB/c mice: 1) control mice, 2) birch pollen-induced allergic mice, and 3) birch pollen-induced allergic mice with SCIT. Tandem mass tag (TMT) labelling coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze the lung proteome in the mice. Ingenuity pathway analysis (IPA) and Gene Ontology (GO) classification analysis were applied to identify differentially expressed proteins (DEPs) and crucial pathways. The screened DEPs were validated by immunohistochemistry analysis. A total of 317 proteins were upregulated and 184 proteins were downregulated in the asthma group compared to those of the control group. In contrast, 639 DEPs (163 upregulated and 456 downregulated proteins) were identified after SCIT in comparison with those of the asthma group. Among the 639 DEPs, 277 proteins returned to similar levels as those of the relative non-asthma condition. Bioinformatic analysis revealed that the 277 proteins played a significant role in the leukocyte extravasation signaling pathway. The leukocyte extravasation signaling pathway and related DEPs were of crucial importance in birch pollen SCIT.

Study of the Expected Impact of Palm Pollen on Human Respiratory Tract Allergy

&lt;b&gt;Background and Objective:&lt;/b&gt; Date-Palm trees (&lt;i&gt;Phoenix dactylifera&lt;/i&gt; L.) are the most abundant crop in Saudi Arabia. Date Palm Pollen (DPP) are considered an important allergens. The reasons for the increase in susceptibility to allergy are not clear. This investigation aimed to link the size, shape, moisture contents and biogenic contents of the collected pollens to susceptibility. &lt;b&gt;Materials and Methods:&lt;/b&gt; Pollens were collected from three different regions in the Kingdom. Date palm pollen sizes were determined in wet and dry states by Microtrac. A microscope with a camera was used to image the forms of date palm pollens. The biogenic amines were determined after extraction using HPLC. Data were analyzed by one-way analysis of variance (ANOVA), using SPSS version 16.0. &lt;b&gt;Results:&lt;/b&gt; There was a variation in the sizes of pollens from different regions ranging between 3.3-704 μm. Most pollen grains are spherical. The concentrations of six biogenic amines were detected in all samples but with different concentrations. They included B-phenyl ethylamine, Putrescine, Cadaverine, Histamine, Tyramine and Spermidine. &lt;b&gt;Conclusion:&lt;/b&gt; The shape and size of the pollen grains studied were variable and will not facilitate deep penetration into the respiratory system but their biogenic contents were very high and suggested to cause allergy.

Short term physician visits and medication prescriptions for allergic disease associated with seasonal tree, grass, and weed pollen exposure across the United States

BACKGROUND

While year-round exposure to pollen is linked to a large burden of allergic diseases, location-specific risk information on pollen types and allergy outcomes are limited. We characterize the relationship between acute exposure to tree, grass and weed pollen taxa and two allergy outcomes (allergic rhinitis physician visit and prescription allergy medication fill) across 28 metropolitan statistical areas (MSA) in the United States.

METHODS

We obtained daily pollen data from National Allergy Bureau (NAB) monitors at these 28 MSAs for 2008-2015. We revised the NAB guidelines to classify taxa-specific pollen severity each day. Daily information on allergic rhinitis and prescribed allergy medications for individuals with employer-based health insurance from the IBM MarketScan Research database for these MSAs. We combined the daily pollen and health data for each MSA into a longitudinal dataset. We conducted a MSA-specific conditional quasi-Poisson regression analysis to assess how different levels of pollen concentration impact the health outcomes, controlling for local air pollution, meteorology and Influenza-like illness (ILI). We used a random effects meta-analysis to produce an overall risk estimate for each pollen type and health outcome.

RESULTS

The seasonal distribution of pollen taxa and associated health impacts varied across the MSAs. Relative risk of allergic rhinitis visits increased as concentrations increased for all pollen types; relative risk of medication fills increased for tree and weed pollen only. We observed an increase in health risk even on days with moderate levels of pollen concentration. 7-day average concentration of pollen had stronger association with the health outcomes compared to the same-day measure. Controlling for air pollution and ILI had little impact on effect estimates.

CONCLUSION

This analysis expands the catalogue of associations between different pollen taxa and allergy-related outcomes across multiple MSAs. The effect estimates we present can be used to project the burden of allergic disease in specific locations in the future as well inform patients with allergies on impending pollen exposure.

The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis

Patients exposed to pollutants are more likely to suffer from allergic rhinitis and may benefit from antioxidant treatment. Our study determined if patients diagnosed with grass-induced allergic rhinitis could benefit from broccoli sprout extract (BSE) supplementation. In total, 47 patients were confirmed with grass-induced allergic rhinitis and randomized to one of four groups: group 1 (nasal steroid spray + BSE), group 2 (nasal steroid spray + placebo tablet), group 3 (saline nasal spray + BSE) and group 4 (saline nasal spray + placebo tablet). Peak Nasal Inspiratory Flow (PNIF), Total Nasal Symptoms Scores (TNSS) and nasal mucus cytokine levels were analyzed in samples collected before and after the 3-week intervention. Comparing before and after the intervention, PNIF improved significantly when comparing Groups 1 and 2, vs. placebo, at various time points (p ≤ 0.05 at 5, 15, 60 and 240 min) following nasal challenge, while TNSS was only statistically significant at 5 (p = 0.03), 15 (p = 0.057) and 30 (p = 0.05) minutes. There were no statistically significant differences in various cytokine markers before and after the intervention. Combining nasal corticosteroid with BSE led to the most significant improvement in objective measures.

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown-no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m3 resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen-virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.

Higher airborne pollen concentrations correlated with increased SARS-CoV-2 infection rates, as evidenced from 31 countries across the globe

Pollen exposure weakens the immunity against certain seasonal respiratory viruses by diminishing the antiviral interferon response. Here we investigate whether the same applies to the pandemic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is sensitive to antiviral interferons, if infection waves coincide with high airborne pollen concentrations. Our original hypothesis was that more airborne pollen would lead to increases in infection rates. To examine this, we performed a cross-sectional and longitudinal data analysis on SARS-CoV-2 infection, airborne pollen, and meteorological factors. Our dataset is the most comprehensive, largest possible worldwide from 130 stations, across 31 countries and five continents. To explicitly investigate the effects of social contact, we additionally considered population density of each study area, as well as lockdown effects, in all possible combinations: without any lockdown, with mixed lockdown-no lockdown regime, and under complete lockdown. We found that airborne pollen, sometimes in synergy with humidity and temperature, explained, on average, 44% of the infection rate variability. Infection rates increased after higher pollen concentrations most frequently during the four previous days. Without lockdown, an increase of pollen abundance by 100 pollen/m³ resulted in a 4% average increase of infection rates. Lockdown halved infection rates under similar pollen concentrations. As there can be no preventive measures against airborne pollen exposure, we suggest wide dissemination of pollen-virus coexposure dire effect information to encourage high-risk individuals to wear particle filter masks during high springtime pollen concentrations.

IL-31 transgenic mice show reduced allergen-induced lung inflammation

Interleukin-31 (IL-31) is a Th2 cell-derived cytokine that has been closely linked to pruritic skin inflammation. More recently, enhanced IL-31 serum levels have also been observed in patients with allergic rhinitis and allergic asthma. Therefore, the main aim of this study was to unravel the contribution of IL-31 to allergen-induced lung inflammation. We analyzed lung inflammation in response to the timothy grass (Phleum pratense) pollen allergen Phl p 5 in C57BL/6 wild-type (wt) mice, IL-31 transgenic (IL-31tg) mice, and IL-31 receptor alpha-deficient animals (IL-31RA-/- ). IL-31 and IL-31RA levels were monitored by qRT-PCR. Cellular infiltrate in bronchoalveolar lavage fluid (BALF) and lung tissue inflammation, mucus production as well as epithelial thickness were measured by flow cytometry and histomorphology. While allergen challenge induced IL-31RA expression in lung tissue of wt and IL-31tg mice, high IL-31 expression was exclusively observed in lung tissue of IL-31tg mice. Upon Phl p 5 challenge, IL-31tg mice showed reduced numbers of leukocytes and eosinophils in BALF and lung tissue as well as diminished mucin expression and less pronounced epithelial thickening compared to IL-31RA-/- or wt animals. These findings suggest that the IL-31/IL-31RA axis may regulate local, allergen-induced inflammation in the lungs.

Experimental Mouse Models of Ragweed- and Papain-Induced Allergic Conjunctivitis

Mouse models of allergic conjunctivitis mimic various aspects of human allergic conjunctivitis. They are useful as acute models of allergic conjunctivitis to study immunological aspects of this condition. In this chapter, we will describe ragweed-pollen-induced experimental allergic conjunctivitis (mostly driven by adaptive immunity), and papain-soaked contact lens-induced experimental allergic conjunctivitis (mostly driven by innate immunity). Giemsa staining of histological sections is used for quantification of the number of infiltrating eosinophils, which is useful to evaluate the severity of the allergic inflammation. Immunohistochemical staining and quantitative PCR are used to clarify spatiotemporal expression of proinflammatory molecules in the conjunctival tissue. Flow cytometric analysis of conjunctival tissue is used for the detection of innate lymphoid cell type 2 (ILC2) in the ocular surface tissues.

Bee pollens originating from different species have unique effects on ovarian cell functions

CONTEXT

The species-specific differences and mechanisms of action of bee pollen on reproduction have not been well studied.

OBJECTIVE

We compared the effects of bee pollen extracts from different plants on ovarian cell functions.

MATERIALS AND METHODS

We compared the effects of pollens from black alder, dandelion, maize, rapeseed, and willow at 0, 0.01, 0.1, 1, 10, or 100 µg/mL on cultured porcine ovarian granulosa cells. Cell viability was assessed with a Trypan blue test, the cell proliferation marker (PCNA), and an apoptosis marker (BAX) were assessed by immunocytochemistry. Insulin-like growth factor (IGF-I) release was measured by an enzyme-linked immunosorbent assay.

RESULTS

Addition of any bee pollen reduced cell viability, promoted accumulation of both proliferation and apoptosis markers, and promoted IGF-I release. The ability of various pollens to suppress cell viability ranked as follows: rapeseed > dandelion > alder > maize > willow. The biological activity of bee pollens regarding their stimulatory action on ovarian cell proliferation ranked as follows: dandelion > willow > maize > alder > rapeseed. Cell apoptosis was promoted by pollens as follows: range > dandelion > alder > rapeseed > willow > maize. The ability of the pollens to stimulate IGF-I output are as follows: willow > dandelion > rapeseed > maize > alder.

DISCUSSION

Bee pollen can promote ovarian cell proliferation by promoting IGF-I release, but it induces the dominance of apoptosis over proliferation and the reduction in ovarian cell viability in a species-specific manner.

CONCLUSIONS

This is the first demonstration of adverse effects of bee pollen on ovarian cell viability and of its direct stimulatory influence on proliferation, apoptosis, and IGF-I release. The biological potency of bee pollen is dependent on the plant species.

LTP allergy/sensitization in a pediatric population

Plant lipid transfer proteins (LTPs) are widespread plant food allergens, highly resistant to food processing and to the gastrointestinal environment, which have been described as the most common food allergens in the Mediterranean area. LTP allergy is widely described in adults, but it represents an emerging allergen also in the pediatric population. Little is known about the real prevalence and the clinical features of this allergy in children and it still often remains underdiagnosed in these patients. An early identification and a deeper knowledge of this allergy in childhood can avoid severe systemic reactions and improve the child's quality of life. Pediatricians should always consider the possibility of LTP involvement in cases of plant-derived food allergy.

Spread of Jacobaea vulgaris and Occurrence of Pyrrolizidine Alkaloids in Regionally Produced Honeys from Northern Germany: Inter- and Intra-Site Variations and Risk Assessment for Special Consumer Groups

Pyrrolizidine alkaloids (PA) and PA N-oxides (PANO) are secondary plant metabolites exhibiting genotoxic and carcinogenic properties. Apart from the roots and leaves, PA/PANO are particularly present in pollen and nectar. Therefore, the spread of Jacobaea vulgaris in certain regions of northern Germany has an impact on the safety of honey produced in that region. In this study, raw honey samples (n = 437) were collected from usually three individual beehives per site (n = 73) in the district of Ostholstein and analyzed for 25 PA/PANO. The results reveal mean levels of 8.4, 1.5, and 72.6 µg/kg and maximum levels of 111, 59.4, and 3313 µg/kg, depending on the season (summer 2015 and spring/summer 2016, respectively). As far as individual data are concerned, sites near areas with J. vulgaris growth did not necessarily result in high PA/PANO values. Furthermore, intra-site investigations revealed remarkable differences in PA/PANO levels of raw honey collected by different bee colonies at the same site. Consumption of these regionally produced honeys entails an increased exposure to PA/PANO, especially in children and high consumers. Margin of exposure values of <10,000 and an exceedance of the health-based guidance value highlight that regionally produced and marketed honey must be considered with care for a proper risk assessment and risk management.

Relevant Patient Benefit of Sublingual Immunotherapy with Birch Pollen Allergen Extract in Allergic Rhinitis: An Open, Prospective, Non-Interventional Study

INTRODUCTION

Sublingual immunotherapy (SLIT) with birch pollen extract has been shown to be an efficacious treatment of allergic rhinitis (AR). An as-yet unanswered question is whether and how clinical benefit translates into patient benefit, i.e. what benefit patients derive from this treatment.

METHODS

This 1-year, open, prospective, multicenter, non-interventional study conducted in 75 German centers measured patient-relevant benefit of birch pollen SLIT (Staloral^® Birch) using the questionnaire "Patient Benefit Index for Allergic Rhinitis (PBI-AR)". At treatment onset, patients rated the importance of 25 treatment needs; after the first birch pollen season on treatment, goal achievement was evaluated. A preference-weighted benefit index was calculated and its association with gender, asthma, allergy status, and severity of AR symptoms was determined.

RESULTS

Mean age of the 291 adult patients was 38.8 years; 58.4% were female. The most important treatment goals were to "be able to stay outdoors without symptoms" (87.3% quite or very important), "no longer have a runny or stuffed-up nose" (86.9%), and "be able to breathe through your nose more freely" (86.9%). The treatment goals with the highest benefit ratings (referring to those patients to whom the respective goal applied) were to "have confidence in the therapy" (60.5% has helped "quite" or "very much"), "have an easily applicable treatment" (55.6%), and "be able to breathe through my nose more freely" (51.7%). The average PBI-AR global score was 2.19 (SD 1.04) (0-4; with 4 indicating maximum benefit). No significant differences in PBI-AR global score or subscales were found between men and women, poly- and monoallergic patients, or patients with severe versus mild rhinoconjunctivitis. Patients with asthma reported relevant but lower benefit than patients without asthma.

CONCLUSION

After 1 year of birch pollen SLIT treatment, patients reported considerable benefit, mainly due to a reduction of physical symptoms and treatment burden.

Association of early viral lower respiratory infections and subsequent development of atopy, a systematic review and meta-analysis of cohort studies

INTRODUCTION

Existing evidence on the relationship between childhood lower respiratory tract infections (LRTI) and the subsequent atopy development is controversial. We aimed to investigate an association between viral LRTI at <5 years and the development of atopy at > 2 years.

METHODS

We conducted a search at Embase, Pubmed, Web of Science, and Global Index Medicus. We collected data from the included articles. We estimated the odds ratio and the 95% confidence intervals with a random effect model. We determined factors associated with atopy development after childhood LRTI using univariate and multivariate meta-regression analyses. We recorded this systematic review at PROSPERO with the number CRD42018116955.

RESULTS

We included 24 studies. There was no relationship between viral LRTI at <5 years and skin prick test-diagnosed-atopy (OR = 1.2, [95% CI = 0.7-2.0]), unknown diagnosed-atopy (OR = 0.7, [95% CI = 0.4-1.3]), atopic dermatitis (OR = 1.2, [95% CI = 0.9-1.6]), hyperreactivity to pollen (OR = 0.8, [95% CI = 0.3-2.7]), food (OR = 0.8, [95% CI = 0.3-2.5]), or house dust mite (OR = 1.1, [95% CI = 0.6-2.2]). Although not confirmed in all studies with a symmetric distribution of the 23 confounding factors investigated, the overall analyses showed that there was a relationship between childhood viral LRTI at < 5 years and serum test diagnosed-atopy (OR = 2.0, [95% CI = 1.0-4.1]), allergic rhinoconjunctivitis (OR = 1.7, [95% CI = 1.1-2.9]), hyperreactivity diagnosed by serum tests with food (OR = 5.3, [1.7-16.7]) or inhaled allergens (OR = 4.2, [95% CI = 2.1-8.5]), or furred animals (OR = 0.6, [95% CI = 0.5-0.9]).

CONCLUSION

These results suggest that there is no association between viral LRTI at < 5 years and the majority of categories of atopy studied during this work. These results, however, are not confirmed for the remaining categories of atopy and more particularly those diagnosed by serum tests. There is a real need to develop more accurate atopy diagnostic tools.

Grass pollen as a trigger of emergency department presentations and hospital admissions for respiratory conditions in the subtropics: A systematic review

INTRODUCTION

It is unknown if high concentration of airborne grass pollen, where subtropical grasses (Chloridoideae and Panicoideae) dominate, is a risk factor for respiratory health. Here we systematically reviewed the association between airborne grass pollen exposure and asthma emergency department (ED) presentations and hospital admissions in subtropical climates.

OBJECTIVES

A systematic review was performed to identify and summarise studies that reported on respiratory health (asthma ED presentations and hospital admissions) and airborne grass pollen exposure in subtropical climates.

METHODS

Searches were conducted in: MEDLINE, Web of Science, Scopus, CINAHL (EBSCO), Embase and Google Scholar databases (1966-2019). Risk of bias was assessed using a validated quality assessment tool. A meta-analysis was planned, however due to the heterogeneity in study design it was determined inappropriate and instead a narrative synthesis was undertaken.

RESULTS

Nineteen studies were identified for inclusion, with a total of 598,931 asthma ED presentation participants and 36,504 asthma hospital admission participants in six countries (Australia, India, Israel, Italy, Spain, USA). The narrative synthesis found airborne grass pollen appears to have a small and inconsistent increase on asthma ED presentations (judged as: probably little effect n = 5, may have little effect n = 4, no effect n = 2 and uncertain if there is an effect n = 4) and hospital admissions (judged as: probably increase slightly n = 2 probably little effect n = 1, may have a little effect n = 1, no effect n = 3 and we are uncertain if there is an effect n = 4) in the subtropics. Furthermore, the reported effect sizes were small and its clinical relevance may be difficult to discern.

CONCLUSION

Exposure to airborne grass pollen appears to have a small and inconsistent increase on asthma ED presentations and hospital admissions in the subtropics. These findings are comparable to reported observations from studies undertaken in temperate regions.

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.

Sulfur or Pollen? Chemical, Biological, and Toxicological Basis for the Correct Risk Communication of Urban Yellow Dust Deposition

Urban yellow dust deposition is a common phenomenon in many parts of the world, which is sometimes called "sulfur shower," "sulfur rain," or "pollen storm." Most people, especially those living in the vicinity of industrial facilities, wrongly perceive the yellow dust as sulfur when in fact it is pollen. The misunderstanding increases risk perception as people believe the "yellow powder" is a serious threat to their health. Based on simple observations, it is virtually impossible to differentiate sulfur from pollen, so risk communication should consider the chemical, biological, and toxicological aspects of these agents. In this review, we clarify that industrial emissions of sulfur are under the form of sulfides, oxides, and other volatile compounds which are gaseous and noncolored, and we explain that it is chemically impossible for gaseous sulfur to become solid yellow sulfur under normal environmental conditions. We also describe pollen and its release from trees, shrubs, and herbs a process influenced by atmospheric conditions. We suggest take-home messages that risk communicators may use when explaining the phenomenon to their communities.

More sneezing, less crime? Health shocks and the market for offenses

A large literature points out that exposure to criminal victimization has far-reaching effects on public health. What remains surprisingly unexplored is that role that health shocks play in explaining aggregate fluctuations in offending. This research finds novel evidence that crime is sensitive to health shocks. We consider the responsiveness of crime to a pervasive and common health shock which we argue shifts costs and benefits for offenders and victims: seasonal allergies. Leveraging daily variation in city-specific pollen counts, we present evidence that violent crime declines in U.S. cities on days in which the local pollen count is unusually high and that these effects are driven by residential violence. While past literature suggests that property crimes have more instrumental motives, require planning, and hence are particularly sensitive to permanent changes in the cost and benefits of crime, we find that violence may be especially sensitive to health shocks.

Assessment of the health impact of paper mulberry (Broussonetia papyrifera L.), an invasive plant species in Islamabad, Pakistan

This study focuses on the risk of pollen allergy due to paper mulberry (Broussonetia papyrifera L.), an Asian invasive plant species now common in large parts of the world. Pollen plays a key role in the pathogenesis of respiratory allergic diseases, particularly rhinitis and asthma, and Islamabad, a major metropolitan city, is severely affected by allergy owing to B. papyrifera pollen. Due to its seasonality and other relationships with climatic variables, we used remote sensing to monitor the trend of pollen count. We also mapped the localisation of patients affected by pollen allergy using geographic information systems. The maximum likelihood algorithm was applied to SPOT-5 satellite imagery for land use/land cover classification. Temporal analysis of remotely sensed data revealed an increasing trend of paper mulberry density towards the southern and south-western part of Islamabad. Although not evident during rainfall, a clear positive correlation was found between patient count and pollen count. Field survey data and hotspot spatial analysis of allergy patients revealed that residents of Shakerperiyan and Lok Virsa areas (Sectors H-8, I-8, I-9, G-8, G-7 and G-6 in Islamabad) had more pronounced symptoms compared to residents of other sectors. The methodology adopted used in this study can be used to map the distribution of similar invasive species in other parts of the country.

Clinical Manifestations and Risk Factors of Anaphylaxis in Pollen-Food Allergy Syndrome

PURPOSE

Many studies have reported that pollen-food allergy syndrome (PFAS) can cause anaphylaxis. No comprehensive investigations into anaphylaxis in PFAS have been conducted, however. In this study, we investigated the clinical manifestations and risk factors for anaphylaxis in PFAS in Korean patients with pollinosis.

MATERIALS AND METHODS

Data were obtained from a nationwide cross-sectional study that previously reported on PFAS in Korean patients with pollinosis. Data from 273 patients with PFAS were collected, including demographics, list of culprit fruits and vegetables, and clinical manifestations of food allergy. We analyzed 27 anaphylaxis patients and compared them with patients with PFAS with oropharyngeal symptoms only (n=130).

RESULTS

The most common cause of anaphylaxis in PFAS was peanut (33.3%), apple (22.2%), walnut (22.2%), pine nut (18.5%), peach (14.8%), and ginseng (14.8%). Anaphylaxis was significantly associated with the strength of sensitization to alder, hazel, willow, poplar, timothy, and ragweed (p<0.05, respectively). Multivariable analysis revealed that the presence of atopic dermatitis [odds ratio (OR), 3.58; 95% confidence interval (CI), 1.25-10.23; p=0.017]; sensitization to hazel (OR, 5.27; 95% CI, 1.79-15.53; p=0.003), timothy (OR, 11.8; 95% CI, 2.70-51.64; p=0.001), or ragweed (OR, 3.18; 95% CI, 1.03-9.87; p=0.045); and the number of culprit foods (OR, 1.25; 95% CI, 1.15-1.37; p<0.001) were related to the development of anaphylaxis in PFAS.

CONCLUSION

The most common culprit foods causing anaphylaxis in PFAS were peanut and apple. The presence of atopic dermatitis; sensitization to hazel, timothy, or ragweed; and a greater number of culprit foods were risk factors for anaphylaxis in PFAS.

Cashew Tree Pollen: An Unknown Source of IgE-Reactive Molecules

Pollinosis is sub-diagnosed and rarely studied in tropical countries. Cashew tree pollen has been reported as an allergen source although the knowledge of its immunoglobulin E (IgE)-reactive molecules is lacking. Therefore, this work aimed to identify IgE-reactive molecules and provide a proteomic profile of this pollen. From the 830 proteins identified by shotgun analysis, 163 were annotated to gene ontology, and a list of 39 proteins filtered for high confidence was submitted to the Allfam database where nine were assigned to allergenic families. Thus, 12 patients from the northeast of Brazil with persistent allergic rhinitis and aggravation of symptoms during cashew flowering season were selected. Using a 2D-based approach, we identified 20 IgE-reactive proteins, four already recognized as allergens, including a homolog of the birch isoflavone-reductase (Bet v 6). IgE-reactivity against the extract in native form was confirmed for five patients in ELISA, with three being positive for Bet v 6. Herein, we present a group of patients with rhinitis exposed to cashew tree pollen with the first description of IgE-binding proteins and a proteomic profile of the whole pollen. Cashew tree pollen is considered an important trigger of rhinitis symptoms in clinical practice in the northeast of Brazil, and the elucidation of its allergenic molecules can improve the diagnostics and treatment for allergic patients.

[Forests and allergies]

OBJECTIVE

Many research papers have addressed the beneficial qualities of forests in promoting mental and physical health. However, we should also be clear that forest environments could have detrimental effects. Some of them, which are of allergic nature, have hitherto been largely neglected.

METHODS

A comprehensive literature search has allowed us to achieve an initial synthesis on this matter. The emphasis was on temperate forests, especially on French forests.

RESULTS

Anemophilous pollen from deciduous trees is the major factor causing respiratory allergies in connection with forests. The risks are focused between mid-winter and late spring. Ash, hornbeam and birch pollen and, more incidentally, oak and beech pollen induce allergic reactions not only in the forests, but also at great distances. As a result of its high humidity and because decaying organic matter is very abundant, the forest environment presents also a breeding ground for mould growth. Accordingly, fungal spores can lead to allergic manifestations recalling pollinosis. Lastly, the "other" allergies mainly include contact dermatitis symptoms, which affect wood workers first and foremost. However, the pine processionary moth, whose zone of infestation is rapidly spreading northwards and whose setae contain several relevant allergens, represents one particular case.

CONCLUSION

Allergic reactions observed in forests or originating in forests are sufficiently frequent to justify to set up a wide-reaching system for aerobiological and epidemiological monitoring.

Ambrosia artemisiifolia L. temperature-responsive traits influencing the prevalence and severity of pollinosis: a study in controlled conditions

BACKGROUND

Ambrosia artemisiifolia L. is one of the most important sources of allergenic pollen in many regions of the world. Its health impact increased over the last decades and is expected to further increase in consequence of climate change. However little information is available on the specific role played by temperature on allergy rising. The aim of this work was to evaluate the effect of temperature on A. artemisiifolia growth, flowering and pollen allergenicity, the major plant functional traits influencing the prevalence and severity of pollinosis.

RESULTS

Plants were grown in controlled conditions at three thermal regimes: "Low" (LT: 18-14 °C light-dark), "Intermediate" (IT: 24-20 °C light-dark) and "High" (HT: 30-26 °C light-dark). During plant development, plant vegetative and reproductive morpho-functional traits were measured and, at the end of plant life-cycle, mature pollen was collected and analyzed for its allergenic properties by slot blot, 1D- and 2D-western blot (by using a pool of sera from ragweed-allergic patients) and liquid chromatography-tandem mass spectrometry. A. artemisiifolia showed a great development plasticity leading to a broad temperature tolerance. Shoot architecture, growth rate, number of male inflorescence and pollen allergenicity were temperature-responsive traits. Pollen allergenicity increased in parallel with temperature and differences were related to allergen synthesis and Amb a 1-IgE-binding. Flavonoids whose concentration in pollen decreased with the increase of temperature, were recognized as the cause of the negligible Amb a 1-IgE binding in LT pollen.

CONCLUSIONS

Results show that temperature governs plant development and pollen allergenicity influencing the temporal and spatial magnitude of subject exposure to allergens.

Environmental grass pollen levels in utero and at birth and cord blood IgE: Analysis of three birth cohorts

BACKGROUND

Early life factors are associated with allergic respiratory diseases, but the role of high grass pollen concentrations during pregnancy and shortly after birth is not known.

OBJECTIVE

To assess outdoor levels of grass pollen during the intrauterine period and at birth during peak pollen season on cord blood IgE in birth cohorts.

METHODS

Three birth cohorts were included: MACS (n = 429), Australia; COPSAC₂₀₀₀ (n = 200), Denmark; and LISA (n = 1968), Germany. Cord blood IgE was categorized (<0.5 kU/L, 0.5-1 kU/L, >1 kU/L) and dichotomized (high IgE ≥ 0.5 kU/L). Birth during the grass pollen season months and cumulative exposure to outdoor grass pollen counts during pregnancy with cord blood IgE were analysed using multinomial regression and analysed in meta-analysis using binomial regression adjusted for potential confounders.

RESULTS

Birth during the grass pollen season had higher pooled odds of cord blood IgE >0.5 kU/L 1.37 (95% CI 1.06, 1.77) in a meta-analysis with little heterogeneity between the three cohorts. Cumulative exposure to outdoor grass pollen counts during the entire pregnancy was associated with slightly lower pooled odds but significant (OR = 0.98, 95% CI: 0.96 to 0.99).

CONCLUSIONS

Birth during grass pollen seasons were associated with increased risk of high cord blood IgE in cities from both hemispheres, but high pollen loads in the environment during the entire pregnancy appeared protective. As IgE responses develop during the first months of life, our study findings provide new insights into the mechanisms of grass pollen exposure at birth and shortly after on possible allergic respiratory diseases.

Does the increase in ambient CO2 concentration elevate allergy risks posed by oak pollen?

Oak pollen is a major respiratory allergen in Korea, and the distribution of oak trees is expected to increase by ecological succession and climate change. One of the drivers of climate change is increasing CO₂, which is also known to amplify the allergy risk of weed pollen by inducing elevated allergenic protein content. However, the impact of CO₂ concentration on tree pollen is not clearly understood due to the experimental difficulties in carrying out extended CO₂ treatment. To study the response of pollen production of sawtooth oak trees (Quercus acutissima) to elevated levels of ambient CO₂, three open-top chambers at the National Institute of Forest Science in Suwon, Korea were utilized with daytime (8 am-6 pm) CO₂ concentrations of ambient (× 1.0, ~ 400 ppm), × 1.4 (~ 560 ppm), and × 1.8 (~ 720 ppm) treatments. Each chamber had three sawtooth oak trees planted in September 2009. One or two trees per chamber matured to bloom in 2016. Five to six catkins were selected per tree and polyethylene bags were attached to collect pollen grains. The total number of catkins per tree was counted and the number and weight of pollen grains per catkin were measured. Oak allergen-Que a 1 (Allergon Co., Uppsala, Sweden)-was extracted and purified to make an ELISA kit by which the antigen levels in the pollen samples were quantified. Total pollen counts per tree of the × 1.4 and × 1.8 treatments showed significant increase of 353 and 1299%, respectively, from the × 1.0 treatment (p < 0.001). Allergenic protein contents at the × 1.4 and × 1.8 treatments also showed significant increase of 12 and 11%, respectively (p = 0.011). The × 1.8 treatment induced significant difference from the × 1.0 treatment in terms of pollen production and allergenic protein content, whereas the × 1.4 treatment showed mixed significance. In summary, the oak trees under the elevated CO₂ levels, which are expected in the changing climate, produced significantly higher amount of pollen and allergenic protein than under the present air conditions.

Uncovering a New Moral Dilemma of Economic Optimization in Biotechnological Processing

The trend of emerging biorefineries is to process the harvest as efficiently as possible and without any waste. From the most valuable phytomass, refined medicines, enzymes, dyes and other special reactants are created. Functional foods, food ingredients, oils, alcohol, solvents, plastics, fillers and a wide variety of other chemical products follow. After being treated with nutrient recovery techniques (for fertilizer production), biofuels or soil improvers are produced from the leftovers. Economic optimization algorithms have confirmed that such complex biorefineries can be financially viable only when a high degree of feedstock concentration is included. Because the plant material is extremely voluminous before processing, the farming intensity of special plants increases in the nearest vicinity of agglomerations where the biorefineries are built for logistical reasons. Interdisciplinary analyses revealed that these optimization measures lead to significantly increased pollen levels in neighbouring urban areas and subsequently an increased risk of allergies, respectively costs to the national health system. A new moral dilemma between the shareholder's profit and public interest was uncovered and subjected to disputation.

Effects of neonicotinoid insecticide exposure and monofloral diet on nest-founding bumblebee queens

Bumblebees are among the world's most important groups of pollinating insects in natural and agricultural ecosystems. Each spring, queen bumblebees emerge from overwintering and initiate new nests, which ultimately give rise to workers and new reproductives later in the season. Nest initiation and survival are thus key drivers of both bumblebee pollination services and population dynamics. We performed the first laboratory experiment with the model bumblebee species Bombus impatiens that explores how early nesting success is impacted by the effects of temporary or more sustained exposure to sublethal levels of a neonicotinoid-type insecticide (imidacloprid at 5 ppb in nectar) and by reliance on a monofloral pollen diet, two factors that have been previously implicated in bumblebee decline. We found that queens exhibited increased mortality and dramatically reduced activity levels when exposed to imidacloprid, as well as delayed nest initiation and lower brood numbers in the nest, but partially recovered from these effects when they only received early, temporary exposure. The effects of pollen diet on individual queen- and colony-level responses were overshadowed by effects of the insecticide, although a monofloral pollen diet alone was sufficient to negatively impact brood production. These findings speak to the sensitivity of queen bumblebees during the nest initiation phase of the colony cycle, with implications for how queens and their young nests are uniquely impacted by exposure to threats such as pesticide exposure and foraging habitat unsuitability.

Repeatability of nasal allergen challenge results: Further validation of the allergic rhinitis clinical investigator collaborative protocols

BACKGROUND

Nasal allergen challenge (NAC) models have been used to study allergic rhinitis and new therapies. Symptoms and biological samples can be evaluated at time points after allergen exposure.

OBJECTIVE

To verify protocol repeatability and adequate interval between allergen exposures.

METHODS

Ten ragweed allergic participants were exposed to incrementally increasing dosages of ragweed allergen intranasally until they achieved a total nasal symptom score (TNSS) of 8 of 12 and a peak nasal inspiratory flow (PNIF) of 50% reduction or more from baseline. Three weeks later, participants were challenged with a cumulative dose equal to the sum of all the allergen doses received at screening. TNSS and PNIF were recorded at regular intervals, including a 24-hour assessment. A subsequent visit was conducted after a further 3 weeks. Nasal secretion samples were collected for cytokine and eosinophil quantification.

RESULTS

Nine participants completed all visits. TNSS and PNIF responses followed previous patterns, with an initial peak at 30 minutes followed by a gradual decline. Most participants reported similar patterns at both NAC visits, although some did not demonstrate the same phenotype at both visits. Some experienced a secondary symptom increase 24 hours after NAC. Eosinophil and cytokine sections followed a similar pattern at both NAC visits.

CONCLUSION

NAC is an adequate method for modeling AR in humans, demonstrating appropriate repeatability of symptoms, nasal mucosal eosinophil, and cytokines. The 24-hour time point, previously not studied in our model, may be beneficial in evaluation of long-acting medications. This three-week interval NAC model will be beneficial for studies in which before and after treatment comparisons are desired.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors

BACKGROUND

A multidisciplinary collaboration investigated the world's largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies.

METHODS

Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions.

FINDINGS

Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m³). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74-2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28-16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died.

INTERPRETATION

Convergent environmental factors triggered a thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity on Nov 21, 2016, creating a new benchmark for emergency and health service escalation. Asian or Indian ethnicity and current doctor-diagnosed asthma portended life-threatening exacerbations such as those requiring admission to an ICU. Overall, the findings provide important public health lessons applicable to future event forecasting, health care response coordination, protection of at-risk populations, and medical management of epidemic thunderstorm asthma.

FUNDING

None.

[The clinical value of China Savin pollen extract used for skin prick test]

Objective:The aim of this study is to evaluate the effectiveness and safety of China Savin pollen extract which was used for skin prick test (SPT) in the diagnosis of China Savin pollen allergy. Method:Patients with diagnosis of allergic diseases were collected from Allergy Department of Peking Union Medical College Hospital. All patients were given SPT with China Savin pollen extract, and the mean wheal diameter (MWD) was measured after 15 minutes. Receiver operating characteristic curve (ROC) analysis was performed based on the results of serum specific immunoglobulin E (sIgE). The effectiveness of SPT in the diagnosis of China Savin pollen allergy was evaluated under different diagnostic cutoff values. Adverse events were also recorded to evaluate the safety. Result:A total of 1 029 patients were enrolled in this study without drop out case. There were 1 007 patients in full analysis set (FAS) and 765 patients in per protocol analysis set (PPS). The elimination rate was 25.66%. The area under the ROC curve of FAS is 0.814 (95%CI: 0.788-0.839); which of PPS is 0.829 (95%CI: 0.801-0.857). Based on the ROC curve of PPS, the optimal and the 95% specificity diagnostic cutoff values of MWD were 3.25 mm and 4.75 mm respectively. Based on different diagnostic cutoff value (3.00, 3.25 and 4.75 mm), the sensitivities of SPT with China Savin pollen extract were 0.740 0 (95%CI: 0.701 6-0.778 4), 0.700 (95%CI: 0.659 8-0.740 2) and 0.532 (95%CI: 0.488 3-0.575 7) respectively, whereas the specificity was gradually increased in sequence, which was 0.769 8 (95%CI: 0.719 1-0.820 5), 0.826 4 (95%CI: 0.780 8-0.872 0) and 0.950 9 (95%CI: 0.924 9-0.976 9) respectively. There were 7 adverse events observed among 6 patients (rate: 0.583%, 6/1 029). The manifestation was mild. There was no severe adverse event. Conclusion:SPT with China Savin pollen extract is an effective and safe tool for the diagnosis of China Savin pollen allergy. The effectiveness of diagnosis could be improved based on integration of medical history and different diagnostic threshold values of SPT.

Air pollution, aeroallergens and suicidality: a review of the effects of air pollution and aeroallergens on suicidal behavior and an exploration of possible mechanisms

OBJECTIVE

Risk factors for suicide can be broadly categorized as sociodemographic, clinical and treatment. There is interest in environmental risk and protection factors for suicide. Emerging evidence suggests a link between environmental factors in the form of air pollution and aeroallergens in relation to suicidality.

METHODS

Herein, we conducted a systematic review of 15 articles which have met inclusion criteria on the aforementioned effects.

RESULTS

The majority of the reviewed articles reported an increased suicide risk alongside increased air pollutants or aeroallergens (i.e. pollen) increase; however, not all environmental factors were explored equally. In specific, studies that were delimited to evaluating particulate matter (PM) reported a consistent association with suicidality. We also provide a brief description of putative mechanisms (e.g. inflammation and neurotransmitter dysregulation) that may mediate the association between air pollution, aeroallergens and suicidality.

CONCLUSION

Available evidence suggests that exposure to harmful air quality may be associated with suicidality. There are significant public health implications which are amplified in regions and countries with greater levels of air pollution and aeroallergens. In addition, those with atopic sensitivity may represent a specific subgroup that is at risk.

Comparative analysis of allergen genes and pro-inflammatory factors in pollen and fruit of apple varieties

Allergy to freshly consumed apple fruits is often associated to pollinosis and manifested as oral allergy syndrome (OAS). The allergenic properties of apple varieties differ greatly, spanning from low allergenic to high allergenic varieties. The knowledge of the genetic determinants for allergenicity has been of great interest in scientific community for several years, but the molecular mechanisms involved are still little understood. Here, factors putatively involved in allergenicity were investigated at biochemical and molecular level in pollen and in fruits of apple varieties differing in their allergenic potential. Among putative sensitizing factors, transglutaminase (TGase) and phospholipase A₂ (PLA₂) were considered together with reactive oxygen species (ROS) and known apple allergen genes, with particular attention devoted to the Mal d 1 gene family, the most important one in sensitization. We found that the expression of some allergen genes and the activities of TGase, PLA₂ and ROS producing enzyme are lower in the hypo-allergenic variety 'Durello di Forlì' in comparison with the high-allergenic genotypes 'Gala' and 'Florina'. These results highlight correlations among allergen expressions, enzymatic activities and apple cultivars; these data underline the possibility that some of them could be used in the future as markers for allergenicity.

A prospective cohort study on ambient air pollution and respiratory morbidities including childhood asthma in adolescents from the western Cape Province: study protocol

BACKGROUND

There is evidence from existing literature that ambient air pollutant exposure in early childhood likely plays an important role in asthma exacerbation and other respiratory symptoms, with greater effect among asthmatic children. However, there is inconclusive evidence on the role of ambient air pollutant exposures in relation to increasing asthma prevalence as well as asthma induction in children. At the population level, little is known about the potential synergistic effects between pollen allergens and air pollutants since this type of association poses challenges in uncontrolled real life settings. In particular, data from sub-Sahara Africa is scarce and virtually absent among populations residing in informal residential settlements.

METHODS/DESIGN

A prospective cohort study of 600 school children residing in four informal settlement areas with varying potential ambient air pollutant exposure levels in the Western Cape in South Africa is carried-out. The study has two follow-up periods of at least six-months apart including an embedded panel study in summer and winter. The exposure assessment component models temporal and spatial variability of air quality in the four study areas over the study duration using land-use regression modelling (LUR). Additionally, daily pollen levels (mould spores, tree, grass and weed pollen) in the study areas are recorded. In the panel study asthma symptoms and serial peak flow measurements is recorded three times daily to determine short-term serial airway changes in relation to varying ambient air quality and pollen over 10-days during winter and summer. The health outcome component of the cohort study include; the presence of asthma using a standardised ISAAC questionnaire, spirometry, fractional exhaled nitric-oxide (FeNO) and the presence of atopy (Phadiatop).

DISCUSSION

This research applies state of the art exposure assessment approaches to characterize the effects of ambient air pollutants on childhood respiratory health, with a specific focus on asthma and markers of airway inflammation (FeNO) in South African informal settlement areas by considering also pollen counts and meteorological factors. The study will generate crucial data on air pollution and asthma in low income settings in sub-Sahara Africa that is lacking in the international literature.

Static and elevated pollen traps do not provide an accurate assessment of personal pollen exposure

Background. Volumetric pollen traps are commonly used to assess pollen exposure. These traps are well suited for estimating the regional mean airborne pollen concentration but are likely not to provide an accurate index of personal exposure. In this study, we tested the hypothesis that hair sampling may provide different pollen counts from those from pollen traps, especially when the pollen exposure is diverse. Methods. We compared pollen counts in hair washes to counts provided by stationary volumetric and gravimetric pollen traps in 2 different settings: urban with volunteers living in short distance from one another and from the static trap and suburban in which volunteers live in a scattered environment, quite far from the static trap. Results. Pollen counts in hair washes are in full agreement with trap counts for uniform pollen exposure. In contrast, for diverse pollen exposure, .individual pollen counts in hair washes vary strongly in quantity and taxa composition between individuals and dates. These results demonstrate that the pollen counts method (hair washes vs. stationary pollen traps) may lead to different absolute and relative contributions of taxa to the total pollen count. Conclusions. In a geographic area with a high diversity of environmental exposure to pollen, static pollen traps, in contrast to hair washes, do not provide a reliable estimate of this higher diversity.

Effect of 2 Years of Treatment With Sublingual Grass Pollen Immunotherapy on Nasal Response to Allergen Challenge at 3 Years Among Patients With Moderate to Severe Seasonal Allergic Rhinitis: The GRASS Randomized Clinical Trial

IMPORTANCE

Sublingual immunotherapy and subcutaneous immunotherapy are effective in seasonal allergic rhinitis. Three years of continuous treatment with subcutaneous immunotherapy and sublingual immunotherapy has been shown to improve symptoms for at least 2 years following discontinuation of treatment.

OBJECTIVE

To assess whether 2 years of treatment with grass pollen sublingual immunotherapy, compared with placebo, provides improved nasal response to allergen challenge at 3-year follow-up.

DESIGN, SETTING, AND PARTICIPANTS

A randomized double-blind, placebo-controlled, 3-parallel-group study performed in a single academic center, Imperial College London, of adult patients with moderate to severe seasonal allergic rhinitis (interfering with usual daily activities or sleep). First enrollment was March 2011, last follow-up was February 2015.

INTERVENTIONS

Thirty-six participants received 2 years of sublingual immunotherapy (daily tablets containing 15 µg of major allergen Phleum p 5 and monthly placebo injections), 36 received subcutaneous immunotherapy (monthly injections containing 20 µg of Phleum p 5 and daily placebo tablets) and 34 received matched double-placebo. Nasal allergen challenge was performed before treatment, at 1 and 2 years of treatment, and at 3 years (1 year after treatment discontinuation).

MAIN OUTCOMES AND MEASURES

Total nasal symptom scores (TNSS; range; 0 [best] to 12 [worst]) were recorded between 0 and 10 hours after challenge. The minimum clinically important difference for change in TNSS within an individual is 1.08. The primary outcome was TNSS comparing sublingual immunotherapy vs placebo at year 3. Subcutaneous immunotherapy was included as a positive control. The study was not powered to compare sublingual immunotherapy with subcutaneous immunotherapy.

RESULTS

Among 106 randomized participants (mean age, 33.5 years; 34 women [32.1%]), 92 completed the study at 3 years. In the intent-to-treat population, mean TNSS score for the sublingual immunotherapy group was 6.36 (95% CI, 5.76 to 6.96) at pretreatment and 4.73 (95% CI, 3.97 to 5.48) at 3 years, and for the placebo group, the score was 6.06 (95% CI, 5.23 to 6.88) at pretreatment and 4.81 (95% CI, 3.97 to 5.65) at 3 years. The between-group difference (adjusted for baseline) was -0.18 (95% CI, -1.25 to 0.90; [P = .75]).

CONCLUSIONS AND RELEVANCE

Among patients with moderate to severe seasonal allergic rhinitis, 2 years of sublingual grass pollen immunotherapy was not significantly different from placebo in improving the nasal response to allergen challenge at 3-year follow-up.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01335139; EudraCT Number: 2010-023536-16.

Identification of IgE- binding pollen protein from Cannabis sativa in pollen-hypersensitive patients from north Pakistan

Cannabis sativa (C.sativa) is well-known for its medicinal, industrial and recreational use. However, allergies in relation to Cannabis sativa (C.sativa) are rarely reported. C. sativa is one of the common weeds found in Pakistan and its pollen grains are common in spring and fall season. Although categorized as an aeroallergen, there are limited number of reports regarding allergenic potential in C. sativa. Therefore, the current study is aimed at exploring the IgE- binding potential among the C. sativa pollen in local pollen allergic patients. Initial screening of C. sativa sensitized individuals was carried out by dot blot from the sera of pollen allergic patients. Proteins from the pollen grains were extracted and resolved on 10% gel. Eight bands were visible on gel however only one protein fragment i.e. of 14KDa size was found to bind to IgE as analyzed through protein gel blot analysis. Strong IgE affinity of a 14 kDa protein fragment from C. sativa pollen extract suggests its allergenic potential. Further study is required to find the exact nature of this protein fragment.

Biological and therapeutic properties of bee pollen: a review

Natural products, including bee products, are particularly appreciated by consumers and are used for therapeutic purposes as alternative drugs. However, it is not known whether treatments with bee products are safe and how to minimise the health risks of such products. Among others, bee pollen is a natural honeybee product promoted as a valuable source of nourishing substances and energy. The health-enhancing value of bee pollen is expected due to the wide range of secondary plant metabolites (tocopherol, niacin, thiamine, biotin and folic acid, polyphenols, carotenoid pigments, phytosterols), besides enzymes and co-enzymes, contained in bee pollen. The promising reports on the antioxidant, anti-inflammatory, anticariogenic antibacterial, antifungicidal, hepatoprotective, anti-atherosclerotic, immune enhancing potential require long-term and large cohort clinical studies. The main difficulty in the application of bee pollen in modern phytomedicine is related to the wide species-specific variation in its composition. Therefore, the variations may differently contribute to bee-pollen properties and biological activity and thus in therapeutic effects. In principle, we can unequivocally recommend bee pollen as a valuable dietary supplement. Although the bee-pollen components have potential bioactive and therapeutic properties, extensive research is required before bee pollen can be used in therapy. © 2016 Society of Chemical Industry.

The Prevalence of Grass Pollen-Related Allergic Rhinoconjunctivitis in Elite Amateur Irish Athletes

Allergic rhinoconjunctivitis (AR/C), has been shown to impact upon athletic performance. The championships of the unique, amateur Irish sports of hurling and Gaelic football (collectively known as GAA) take place during the prime pollen months of summer. Elite GAA players must perform optimally when most exposed to pollen. Elite GAA subjects (n=254) underwent skin prick testing to 6 aeroallergens and completed a validated questionnaire (AQUA), producing a score indicating likelihood of having allergy. The prevalence of allergy (positive to at least one aeroallergen on SPT and positive AQUA score) was 27.1% (n=69). Sixteen and a half percent (n=42) of the subjects tested had grass pollen AR/C while 22% (n=54) had house dust mite AR/C, though none were on standard medical therapies or had used allergen-specific immunotherapy. Grass pollen AR/C prevalence appears as common in elite Irish athletes as it is in other countries. It appears to be mild rather than well controlled in these subjects.