Pollen respiratory allergy: Is it really seasonal?

Urban greenspace under a changing climate: Benefit or harm for allergies and respiratory health?

An increasing proportion of the world's population lives in urban settings that have limited greenspace. Urbanization puts pressure on existing greenspace and reduces its access. Climate impacts, including increased temperature and extreme weather events, challenge the maintenance of urban vegetation, reducing its ecosystem services and benefits for human health. Although urban greenspace has been positively associated with numerous health indicators, the evidence for allergies and respiratory health is much less clear and mixed. To address these uncertainties, a workshop with 20 global participants was held in Munich, Germany, in May 2024, focusing on the impact of greenspace-related co-exposures on allergies and respiratory health. This narrative review captures key insights from the workshop, including the roles of urban greenspace in (1) climate change mitigation, (2) interactions with pollen, and (3) emissions of biogenic volatile organic compounds and their byproducts, such as ozone. Additionally, it presents research and stakeholder recommendations from the workshop. Future studies that integrate advanced greenspace exposure assessments and consider the interplay of greenspace with pollen and biogenic volatile organic compounds, along with their relevant byproducts are needed. Increased public awareness and policy actions will also be essential for developing urban greenspace that maximizes health benefits, minimizes risks, and ensures resilience amid a changing climate and rapid urbanization.

The Association of Childhood Allergic Diseases with Prenatal Exposure to Pollen Grains Through At-Birth DNA Methylation

BACKGROUND

Pollen exposure in early life is shown to be associated with allergy and asthma. DNA methylation (DNAm), an epigenetic marker, potentially reacts to pollen. However, the role of at-birth DNAm between prenatal pollen grain (PPG) exposure and childhood asthma and allergic rhinitis is unknown.

METHODS

Data in a birth cohort study on the Isle of Wight, UK, were analyzed (n = 236). Newborn DNAm was measured in cord blood or blood spots on Guthrie cards and screened for potential association with PPG exposure using the R package ttScreening. CpGs that passed screening were further assessed for such associations via linear regressions with adjusting covariates included. Finally, DNAm at PPG-associated CpGs were evaluated for their association with asthma and allergic rhinitis using logistic regressions, adjusting for covariates. The impact of cell heterogeneity on the findings was assessed. Statistical significance was set at p < 0.05.

RESULTS

In total, 42 CpGs passed screening, with 41 remaining statistically significant after adjusting for covariates and cell types (p < 0.05). High PPG exposure was associated with lower DNAm at cg12318501 (ZNF99, β = -0.029, p = 0.032) and cg00929606 (ADM2, β = -0.023, p = 0.008), which subsequently was associated with decreased odds of asthma (OR = 0.11, 95% CI 0.02-0.53, p = 0.006; OR = 0.14, 95% CI 0.02-1.00, p = 0.049). For rhinitis, cg15790214 (HCG11) was shown to play such a role as a mediator (β = -0.027, p ≤ 0.0001; OR = 0.22, 95% CI 0.07-0.72, p = 0.01).

CONCLUSIONS

The association of PPG exposure with childhood asthma and allergic rhinitis incidence is potentially mediated by DNAm at birth.

Polymerised mite allergoids with glutaraldehyde reduce proteolytic activity and enhance the stability of allergen mixtures: a proof of concept with grass mixtures

Background

Polysensitized patients require allergen immunotherapy (AIT) targeting multiple allergens. However, combining allergen extracts can lead to instability and reduced efficacy particularly due to the high proteolytic activity of house dust mite (HDM) allergens. While is known that glutaraldehyde cross-linking may reduce enzymatic activity, its ability to stabilize multi-allergen formulations and protect key allergens from degradation remains unexplored.

Objective

To evaluate the impact of glutaraldehyde polymerization on the stability and immunogenicity of HDM and grass pollen allergen formulations, addressing proteolytic activity challenges in multi-allergen vaccines.

Methods

Stability was assessed over 24 months through protein quantification and antigenic activity assays. Proteolytic activity of HDM-containing extracts was measured using Azocoll, and peptide substrate-based enzymatic assays. Grass pollen allergen degradation was evaluated by SDS-PAGE, immunoblotting, and ELISA Immunogenicity was assessed in mice immunized with grass allergoids alone or in combination with glutaraldehyde-polymerised HDM, measuring IgG responses, splenocyte proliferation, and IL-10 production.

Results

Glutaraldehyde polymerization significantly reduced HDM proteolytic activity (p < 0.0001), achieving reductions of 97.7%, 77.9%, and 89.9% in total protease activity, cysteine protease activity, and serine protease activity, respectively. This inhibition protected grass pollen allergens when mixed with HDM from degradation, ensuring consistent protein content and antigenic activity over 24 months. Mice immunized with grass allergoids alone or combined with polymerised mite extracts showed similar IgG responses and T-cell activation, indicating no compromise in the immune response to grass allergens, with IL-10 secretion confirming preserved regulatory responses.

Conclusions

Polymerised allergen extracts address the challenges of proteolytic degradation in multi-allergen formulations, offering stable, immunogenic vaccines that maintain efficacy and provide a reliable treatment option for polyallergic patients.

Exposure to smoking and greenspace are associated with allergy medicine use - A study of wastewaterin 28 cities of China

Allergies have become an important public health issue as their occurrence is reportedly on the rise around the world. Exposure to environmental factors is considered as trigger for allergic diseases. However, there was limited data on the importance of each factor, particularly in China. In this study, we aimed to investigate the association between occurrence of allergic diseases with exposure to multiple environmental factors via wastewater surveillance across 28 cities in China. The surveillance was conducted by measuring biomarkers of proxies of allergic diseases, i.e. antihistamines, asthma drug, and of smoking, i.e. cotinine in wastewater. Data of green space and air quality were also collected. We observed the level of antihistamine use were significantly associated with smoking, green space and pollen but not significant with air pollution. People in Northern China used more antihistamines than their compatriots in Southern China, an observation aligning with previous reporting of more allergy prevalence in the North than the South of China. Our study affirmed that in China smoking is responsible for a rise in allergy and asthma in the population. Meanwhile, selected sensitizing pollens (occurring during summer) could have stronger impact to trigger allergies than other pollens (occurring in winter).

Maackiain: A comprehensive review of its pharmacology, synthesis, pharmacokinetics and toxicity

Maackiain is an important component of some herbs in traditional Chinese medicine (TCM), such as Sophora flavescens Aiton, Spatholobus suberectus Dunn and Paeonia lactiflora Pall. Maackiain belongs to the second largest group of isoflavonoids the pterocarpans that is widespread in several plant genera, for example Maackia, Sophora, Caragana, Trifolium and Millettia. Recently, maackiain has attracting more attention because of its numerous pharmacological properties. This review offers the first extensive overview of maackiain natural isolation sources, pharmacological activities, synthesis, toxicity, and pharmacokinetic properties. The literature search published between 1962 and 2023 were reported by collecting the data from Google Scholar, Science Direct, SpringerLink, Web of Science, PubMed, Wiley Online, China National Knowledge Infrastructure, Scopus and structure search in SciFinder. Finding reveals the broad range of pharmacological activities of maackiain, such as anti-inflammatory, sepsis prevention, anti-cancer, anti-allergic, anti-osteolytic, anti-obesity, nephroprotective, antifungal, neuroprotective, anti-leukemic, antimalarial and inflammasome activation. Based on findings of pharmacokinetic studies, it is observed that maackiain possesses a low level of bioavailability and absorption and a rapid rate of elimination, but maackiain absorption rates in the extract were comparatively much higher than pure forms because of higher solubility and may reduce the metabolism by other ingredients present in the extract. Toxicity investigations revealed that maackiain is non-toxic to the majority of cells and selectively cytotoxic. After witnessing the beneficial pharmacological properties of maackiain, it is believed to be an emerging drug candidate for the treatment of inflammation, allergic, nephroprotection in T2D, depression, or Alzheimer's disease and obesity. However, future research topics should likely to include that elucidates its mechanism of toxicity and in vivo proper tracking of its conducts in drug delivery system. Integrating toxicity and efficiency, as well as structure modification, are critical approaches to enhancing its pharmacological properties and oral bioavailability.

Molecular Signatures of Aeroallergen Sensitization in Respiratory Allergy: A Comparative Study Across Climate-Matched Populations

Climate change is significantly altering the dynamics of airborne allergens, affecting their seasonality, allergenicity, and geographic distribution, which correlates with increasing rates of allergic diseases. This study investigates aeroallergen sensitization among populations from Tenerife, Spain, and Lima, Peru-two regions with similar climates but distinct socio-economic conditions. Our findings reveal that Spanish individuals, particularly those with asthma, demonstrate higher sensitization levels to a broader range of allergens, especially mites, with 85% of participants reacting to at least one mite allergen. In contrast, Peruvian patients exhibit a narrower spectrum of sensitization. These results highlight the influence of environmental factors, such as pollution and socio-economic disparities, on allergen exposure and immune responses. Moreover, this study underscores the necessity for region-specific diagnostic and therapeutic strategies to effectively address these variations. By elucidating the intricate relationship between climate change, environmental factors, and allergen sensitization, this research offers insights into respiratory allergic conditions, advocating for tailored interventions to mitigate their impact across diverse populations.

Evaluating the Therapeutic Potential of Microneedle Patch Laser With Multiple Wavelengths in Allergic Rhinitis: Insights From an Allergic Rhinitis Mouse Model

OBJECTIVE

There is insufficient evidence to determine the effectiveness of treating allergic rhinitis with a patch laser affix to the skin as opposed to direct intranasal irradiation of the nasal mucosa. We aimed to evaluate the effect of the microneedle patch laser with multiple wavelengths in an allergic rhinitis (AR) mouse model and its underlying mechanism.

METHODS

The microneedle patch laser was attached to the skin above the mouse's nasal cavity, transmitting light to the nasal mucosa. For 10 days, the microneedle patch laser administered simultaneous exposure to wavelengths of 670, 780, 850, and 910 nm at either 10 or 20 min each day. Multiple allergic parameters were evaluated following the microneedle patch laser treatment.

RESULTS

Microneedle patch laser treatment decreased allergic symptoms and inhibited OVA-specific IgE levels. Additionally, it significantly reduced eosinophil infiltration, epithelial thickness of the nasal mucosa, and IL-4 cytokine levels.

CONCLUSION

The light emitted by the microneedle patch laser attached to the skin, penetrated effectively to the nasal mucosa within the nasal cavity, suggesting potential for treating allergic rhinitis in mice and could be extended in clinical applications.

The Acari Hypothesis, V: deciphering allergenicity

The Acari Hypothesis posits that acarians, i.e., mites and ticks, are operative agents of allergy. It derived from observations that allergens are molecular elements of acarians or acarian foodstuffs. A corollary of The Hypothesis provides how acarian dietary elements are selected as allergens; namely, a pattern recognition receptor native to the acarian digestive tract complexes with dietary molecules problematic to the acarian. By virtue of its interspecies operability, the receptor then enables not only removal of the dietary elements by the acarian immune system, but also-should such a complex be inoculated into a human-production of an element-specific IgE. Because pattern recognition receptors bind to molecules problematic to the organism from which the receptors originate, it follows that molecules targeted by adaptive IgE, i.e., allergens, must be problematic to acarians. This claim is supported by evidence that host organisms, when infested by acarians, upregulate representative members of allergenic molecular families. Appreciation of the relationship between allergens and acarians provides insight well beyond allergy, shedding light also on the anti-acarian defenses of many living things, especially humans.

Comparative analysis of airborne fungal spore distribution in urban and rural environments of Slovakia

Monitoring airborne fungal spores is crucial for public health and plant production since they belong to important aeroallergens and phytopathogens. Due to different land use, their concentration can differ significantly between urban and rural areas. We monitored their spectrum and quantity on two geographically close sites with a different degree of urbanisation: Bratislava City and Kaplna Village in Slovakia, located 38 km apart. We recorded the spectrum of airborne fungal spores over a year and confirmed the microscopic results by amplicon-based metagenomic analysis. The main spore season of the most frequent genera lasted over a week longer in Kaplna, but its intensity was approximately two-fold higher in Bratislava. This can be possibly connected to the microclimatic conditions of the urban area (especially wind speed and heat island effect) and the lesser use of fungicides. Cladosporium was the dominant genus on both sites, influencing the intensity most significantly. Through statistical analysis of the influence of meteorological parameters on airborne fungal spore levels, we identified a significant relationship with temperature, while the impact of other parameters varied depending on the spore type and release mechanism. Our results show the differences in airborne fungal spore levels between urban and rural areas and highlight the necessity for more monitoring stations in various environments.

Twenty-five years: The fexofenadine clinical experience

Allergic rhinitis (AR) and urticaria affect a sizable portion of the population worldwide, resulting in reduced quality-of-life and productivity and increased healthcare costs. Fexofenadine (FEX) is a non-sedating second-generation H1 antihistamine with pronounced efficacy and a very good safety profile, used for the treatment of allergic diseases. In addition to its antihistaminic properties, FEX also has anti-inflammatory effects. FEX has a wide therapeutic window and is not associated with any sedative effects, even at higher than recommended doses. There is a need for an integrated management system for AR and urticaria which includes safe and effective treatment options. An ideal anti-allergic formulation should provide fast relief of symptoms and long-lasting effect without drowsiness. Data from randomized clinical trials show that FEX meets these criteria and is an effective treatment option with a favourable safety profile, improving the quality of life of patients suffering from AR and urticaria.

Mapping pollen allergenicity from urban trees in Valencia: A tool for green infrastructure planning

Urban trees provide many benefits to citizens but also have associated disservices such as pollen allergenicity. Pollen allergies affect 40% of the European population, a problem that will be exacerbated with climate change by lengthening the pollen season. The allergenic characteristics of the urban trees and urban parks of the city of Valencia (Spain) have been studied. The Value of Potential Allergenicity (VPA) was calculated for all species. The most abundant allergenic trees with a very high VPA were the cypresses, followed by Platanus x hispanica and species of genera Morus, Acer and Fraxinus, with a high VPA. On the contrary, Citrus x aurantium, Melia azedarach, Washingtonia spp., Brachychiton spp. and Jacaranda mimosifolia were among the most abundant low allergenic trees. VPA was mapped for the city and a hot spot analysis was applied to identify areas of clustering of high and low VPA values. This geostatistical analysis provides a comprehensive representation of the VPA patterns which is very useful for urban green infrastructure planning. The Index of Urban Green Zone Allergenicity (IUGZA) was calculated for the main parks of the city. The subtropical and tropical flora component included many entomophilous species and the lowest share of high and very high allergenic trees in comparison with the Mediterranean and Temperate components. Overall, a diversification of tree species avoiding clusters of high VPA trees, and the prioritization of species with low VPA are good strategies to minimize allergy-related impacts of urban trees on human health.

Effects of extreme weather on health in underserved communities

Increased fossil fuel use has increased carbon dioxide concentrations leading to global warming and climate change with increased frequency and intensity of extreme weather events such as thunderstorms, wildfires, droughts, and heat waves. These changes increase the risk of adverse health effects for all human beings. However, these experiences do not affect everyone equally. Underserved communities, including people of color, the elderly, people living with chronic conditions, and socioeconomically disadvantaged groups, have greater vulnerability to the impacts of climate change. These vulnerabilities are a result of multiple factors such as disparities in health care, lower educational status, and systemic racism. These social inequities are exacerbated by extreme weather events, which act as threat multipliers increasing disparities in health outcomes. It is clear that without human action, these global temperatures will continue to increase to unbearable levels creating an existential crisis. There is now global consensus that climate change is caused by anthropogenic activity and that actions to mitigate and adapt to climate change are urgently needed. The 2015 Paris Accord was the first truly global commitment that set goals to limit further warming. It also aimed to implement equity in action, founded on the principle of common but differentiated responsibilities. Meeting these goals requires individual, community, organizational, national, and global cooperation. Health care professionals, often in the frontline with firsthand knowledge of the health impacts of climate change, can play a key role in advocating for just and equitable climate change adaptation and mitigation policies.

NLRP3 promotes allergic responses to birch pollen extract in a model of intranasal sensitization

Introduction & Objective

Allergic sensitization is an essential step in the development of allergic airway inflammation to birch pollen (BP); however, this process remains to be fully elucidated. Recent scientific advances have highlighted the importance of the allergen context. In this regard, microbial patterns (PAMPs) present on BP have attracted increasing interest. As these PAMPs are recognized by specialized pattern recognition receptors (PRRs), this study aims at investigating the roles of intracellular PRRs and the inflammasome regulator NLRP3.

Methods

We established a physiologically relevant intranasal and adjuvant-free sensitization procedure to study BP-induced systemic and local lung inflammation.

Results

Strikingly, BP-sensitized Nlrp3-deficient mice showed significantly lower IgE levels, Th2-associated cytokines, cell infiltration into the lung, mucin production and epithelial thickening than their wild-type counterparts, which appears to be independent of inflammasome formation. Intriguingly, bone-marrow chimera revealed that expression of NLRP3 in the hematopoietic system is required to trigger an allergic response.

Conclusion

Overall, this study identifies NLRP3 as an important driver of BP-induced allergic immune responses.

The Sensitization Differences of Pollen Allergen Components in Patients with Asthma and/or Rhinitis in Southern China

INTRODUCTION

This study aim to analyzed the main pollen allergen components that cause allergic asthma and/or rhinitis and the cross-reactions between the allergen components.

METHODS

Twenty one allergic rhinitis patients and 23 allergic asthma patients with pollen sensitization from the China Biological Information Repository of Respiratory Diseases were included. All the patients were detected serum pollen allergens components specific immunoglobulin E (sIgE) including Betula verrucosa (Bet v 1, Bet v 2, Bet v 4), Quercus alba (Pla a 1, Pla a 2), Ambrosia elatior (Amb a 1), Artemisia vulgaris (Art v 1, Art v 3, Art v 4), Bermuda grass (Cyn d 1, Cyn d 12), Phleum pratense (Phl p 5, Phl p 1, Phl p 4, Phl p 7, Phl p 12), and cross-reactive carbohydrate determinants.

RESULTS

In patients with asthma, Phl p 4 had the highest positive rate (60.9%), followed by Phl p 1 (43.5%) and Pla a 2 (34.8%), while in patients with rhinitis, Amb a 1 had the highest positive rate (71.4%), followed by Phl p 4 (61.9%) and Pla a 2 (42.9%). Meanwhile, Phl p 1 (43.5%) in asthma patients was higher than that in rhinitis (4.7%, p = 0.03), while Amb a 1 (71.4%) in rhinitis patients was higher than that in asthma (26.1%, p = 0.03). Interestingly, optimal scale analysis show that the severity of both asthma and rhinitis is related to Bet v 4 (Cronbach's Alpha = 95.0%).

CONCLUSIONS

In general, Phl p 4 is the main allergenic component in pollen sensitized asthma patients, while Amb a 1 is the main allergenic component in pollen sensitized rhinitis patients. Sensitization to Bet v 4 may lead to more severe symptoms, and this result may be applied in future clinical precise diagnosis.

Anti-allergic effect of Cyclopia (honeybush) extracts via anti-degranulation activity in a murine allergy model for inhaled antigen

The anti-allergic effects of extracts prepared from two species of honeybush, Cyclopia genistoides and Cyclopia subternata, were demonstrated in vivo in a murine allergy model for inhaled antigen induced with ovalbumin (OVA) inhalation to mimic pollen allergy. Intake of the extracts increased the production of OVA-specific immunoglobulin (Ig) E (IgE), IgG1, and IgG2a antibodies in serum and significantly suppressed anaphylactic reaction-induced body temperature decline. Moreover, the extracts significantly inhibited antigen-antibody-induced degranulation in RBL-2H3 cells. They also inhibited body temperature decline when the allergic mice were given them after antigen sensitization, indicating that anti-degranulation activity is the major mechanism underlying the anti-allergic effect of Cyclopia extracts. Despite their qualitative and quantitative differences in phenolic composition, the two extracts exhibited similar effects, suggesting that several active compounds might be involved in the activity. Therefore, oral administration of either Cyclopia extract potentially exerts a systemic anti-allergic effect, supporting the increased consumption of honeybush tea for general wellness and improved quality of life.

[Study on allergen components of birch pollen in Beijing area]

Objective:To explore the allergen components of birch pollen in the Beijing area and interpret its clinical significance. Methods:A total of 58 patients with birch pollen allergy were included in the cross-sectional study and divided into allergic rhinitis（AR） and allergic asthma（AA） groups according to clinical manifestations. Concentration of birch pollen allergen sIgE, as well as Bet v 1, Bet v 2, Bet v 4 and Bet v 6 sIgE were detected by ImmunoCAP immunolinked immunoassay. Differences of sIgE concentration of birch pollen allergen component in AR and AA were analyzed. Results:There were 44（75.9%） cases of AR and 14（24.1%） cases of AA were enrolled. All the 18 patients with spring pollen allergy were AR patients without AA. There were 40 cases with both spring and autumn pollen allergy, of which 26 cases（65%） were AR and 14 cases（35%） were AA. The sIgE of birch pollen allergen was level 2 or above in all subjects. 94.8% were positive for any four allergen components. 77.6% were mono-sensitized to any allergen component while 17.2% were dual-sensitized. The positive rate of Bet v 1 and/or Bet v 2 was 93.1%. The positive rates of four protein components were: Bet v 1（82.8%）, Bet v 2（29.3%）, Bet v 6（1.7%）, Bet v 4（0%）. sIgE of birch pollen was positively correlated with sIgE level of Betv 1（r=0.898, P<0.001）. The sIgE concentration of Bet v2 in AA group was significantly higher than that in AR group（[4.34±14.35] kUA/L vs [1.56±3.26] kUA/L, P<0.05）. There was no significant difference in other components. Conclusion:Bet v 1 is the main allergen component of birch pollen in the Beijing area, and Bet v 1 plus Bet v 2 can diagnose more than 90% of birch pollen allergy.