Eucalyptus pollen allergy and asthma in children: a cross-sectional study in South-East Queensland, Australia

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.

Decrypting seasonal patterns of key pollen taxa in cool temperate Australia: A multi-barcode metabarcoding analysis

Pollen allergies pose a considerable global public health concern. Allergy risk can vary significantly within plant families, yet some key pollen allergens can only be identified to family level by current optical methods. Pollen information with greater taxonomic resolution is therefore required to best support allergy prevention and self-management. We used environmental DNA (eDNA) metabarcoding to deepen taxonomic insights into the seasonal composition of airborne pollen in cool temperate Australia, a region with high rates of allergic respiratory disease. In Hobart, Tasmania, we collected routine weekly air samples from December 2018 until October 2020 and sequenced the internal transcribed spacer 2 (ITS2) and chloroplastic tRNA-Leucine tRNA-Phenylalanine intergenic spacer (trnL-trnF) regions in order to address the following questions: a) What is the genus-level diversity of known and potential aeroallergens in Hobart, in particular, in the families Poaceae, Cupressaceae and Myrtaceae? b) How do the atmospheric concentrations of these taxa change over time, and c) Does trnL-trnF enhance resolution of biodiversity when used in addition to ITS2? Our results suggest that individuals in the region are exposed to temperate grasses including Poa and Bromus in the peak grass pollen season, however low levels of exposure to the subtropical grass Cynodon may occur in autumn and winter. Within Cupressaceae, both metabarcodes showed that exposure is predominantly to pollen from the introduced genera Cupressus and Juniperus. Only ITS2 detected the native genus, Callitris. Both metabarcodes detected Eucalyptus as the major Myrtaceae genus, with trnL-trnF exhibiting primer bias for this family. These findings help refine our understanding of allergy triggers in Tasmania and highlight the utility of multiple metabarcodes in aerobiome studies.

Identification of allergens in Artocarpus heterophyllus, Moringa oleifera, Trianthema portulacastrum and Syzygium samarangense

BACKGROUND

It is clinically important to identify allergens in Artocarpus heterophyllus (jackfruit), Moringa oleifera (moringa), Trianthema portulacastrum (horse purslane) and Syzygium samarangense (rose apple). This study included 7 patients who developed anaphylaxis to jackfruit (1), moringa (2), horse purslane (3) and rose apple (1). We sought to determine allergens in the edible ripening stages of jackfruit (tender, mature, and ripened jackfruit) and seeds, edible parts of moringa (seeds, seedpod, flesh inside seedpod, and leaves), horse purslane leaves and ripened rose apple fruit. The persistence of the allergens after cooking was also investigated.

METHODS

Allergens were identified by clinical history followed by a skin prick test. Protein profiles of plant/fruit crude protein extracts were determined by SDS-PAGE. Molecular weights of the allergens were determined by immunoblotting with patient sera.

RESULTS

A heat-stable allergen of 114 kDa in A. heterophyllus which is shared among different ripening stages and seeds was identified. Additionally, 101 kDa allergen in boiled tender jackfruit, 86 kDa allergen in boiled seeds and 80 kDa allergen in boiled mature jackfruit were identified. Five heat-stable allergens of 14, 23, 35, 43, and 48 kDa in M. oleifera, 1 heat-stable allergen of 97 kDa in T. portulacastrum, and 4 allergens of 26, 31. 60, and 82 kDa in S. samarangense were identified.

CONCLUSION

Novel IgE-sensitive proteins of A. heterophyllus, M. oleifera, T. portulacastrum and S. samarangense were identified which would be especially useful in the diagnosis of food allergies. The identified allergens can be used in Component Resolved Diagnostics (CRD).

Beyond Cleansing: Ecosystem Services Related to Phytoremediation

Phytotechnologies used for cleaning up urban and suburban polluted soils (i.e., brownfields) have shown some weakness in the excessive extent of the timeframe required for them to be effectively operating. This bottleneck is due to technical constraints, mainly related to both the nature of the pollutant itself (e.g., low bio-availability, high recalcitrance, etc.) and the plant (e.g., low pollution tolerance, low pollutant uptake rates, etc.). Despite the great efforts made in the last few decades to overcome these limitations, the technology is in many cases barely competitive compared with conventional remediation techniques. Here, we propose a new outlook on phytoremediation, where the main goal of decontaminating should be re-evaluated, considering additional ecosystem services (ESs) related to the establishment of a new vegetation cover on the site. The aim of this review is to raise awareness and stress the knowledge gap on the importance of ES associated with this technique, which can make phytoremediation a valuable tool to boost an actual green transition process in planning urban green spaces, thereby offering improved resilience to global climate change and a higher quality of life in cities. This review highlights that the reclamation of urban brownfields through phytoremediation may provide several regulating (i.e., urban hydrology, heat mitigation, noise reduction, biodiversity, and CO₂ sequestration), provisional (i.e., bioenergy and added-value chemicals), and cultural (i.e., aesthetic, social cohesion, and health) ESs. Although future research should specifically be addressed to better support these findings, acknowledging ES is crucial for an exhaustive evaluation of phytoremediation as a sustainable and resilient technology.

Characterising non-linear associations between airborne pollen counts and respiratory symptoms from the AirRater smartphone app in Tasmania, Australia: A case time series approach

Pollen is a well-established trigger of asthma and allergic rhinitis, yet concentration-response relationships, lagged effects, and interactions with other environmental factors remain poorly understood. Smartphone technology offers an opportunity to address these challenges using large, multi-year datasets that capture individual symptoms and exposures in real time. We aimed to characterise associations between six pollen types and respiratory symptoms logged by users of the AirRater smartphone app in Tasmania, Australia. We analyzed 44,820 symptom reports logged by 2272 AirRater app users in Tasmania over four years (2015-2019). With these data we evaluated associations between daily respiratory symptoms and atmospheric pollen concentrations. We implemented Poisson regression models, using the case time series approach designed for app-sourced data. We assessed potentially non-linear and lagged associations with (a) total pollen and (b) six individual pollen taxa. We adjusted for seasonality and meteorology and tested for interactions with particulate air pollution (PM_2.5). We found evidence of non-linear associations between total pollen and respiratory symptoms for up to three days following exposure. For total pollen, the same-day relative risk (RR) increased to 1.31 (95% CI: 1.26-1.37) at a concentration of 50 grains/m³ before plateauing. Associations with individual pollen taxa were also non-linear with some diversity in shapes. For all pollen taxa the same-day RR was highest. The interaction between total pollen and PM_2.5 was positive, with risks associated with pollen significantly higher in the presence of high concentrations of PM_2.5. Our results support a non-linear response between airborne pollen and respiratory symptoms. The association was strongest on the day of exposure and synergistic with particulate air pollution. The associations found with Dodonaea and Myrtaceae highlight the need to further investigate the role of Australian native pollen types in allergic respiratory disease.

Global Climate Change and Pollen Aeroallergens: A Southern Hemisphere Perspective

Climatic change will have an impact on production and release of pollen, with consequences for the duration and magnitude of aeroallergen seasonal exposure and allergic diseases. Evaluations of pollen aerobiology in the southern hemisphere have been limited by resourcing and the density of monitoring sites. This review emphasizes inconsistencies in pollen monitoring methods and metrics used globally. Research should consider unique southern hemisphere biodiversity, climate, plant distributions, standardization of pollen aerobiology, automation, and environmental integration. For both hemispheres, there is a clear need for better understanding of likely influences of climate change and comprehending their impact on pollen-related health outcomes.

Can smartphone data identify the local environmental drivers of respiratory disease?

Asthma and allergic rhinitis (or hay fever) are ubiquitous, chronic health conditions that seasonally affect a sizeable proportion of the population. Both are commonly triggered or exacerbated by environmental conditions including aeroallergens, air quality and weather. Smartphone technology offers new opportunities to identify environmental drivers by allowing large-scale, real-time collection of day-to-day symptoms. As yet, however, few studies have explored the potential of this technology to provide useful epidemiological data on environment-symptom relationships. Here, we use data from the smartphone app 'AirRater' to examine relationships between asthma and allergic rhinitis symptoms and weather, air quality and pollen loads in Hobart, Tasmania, Australia. We draw on symptom data logged by app users over a three-year period and use time-series analysis to assess the relationship between symptoms and environmental co-variates. Symptoms are associated with particulate matter (IRR 1.06, 95% CI: 1.04-1.08), maximum temperature (IRR 1.28, 95% CI: 1.13-1.44) and pollen taxa including Betula (IRR 1.04, 95% CI: 1.02-1.07), Cupressaceae (IRR 1.02, 95% CI: 1.01-1.04), Myrtaceae (IRR 1.06, 95% CI: 1.02-1.10) and Poaceae (IRR 1.05, 95% CI: 1.01-1.09). The importance of these pollen taxa varies seasonally and more taxa are associated with allergic rhinitis (eye/nose) than asthma (lung) symptoms. Our results are congruent with established epidemiological evidence, while providing important local insights including the association between symptoms and Myrtaceae pollen. We conclude that smartphone-sourced data can be a useful tool in environmental epidemiology.

Essential oils, asthma, thunderstorms, and plant gases: a prospective study of respiratory response to ambient biogenic volatile organic compounds (BVOCs)

Purpose: Prevailing opinion is that wind-pollinated plants affect asthma negatively and that insect- pollinated ones do not. "Thunderstorm" asthma, too, is attributed to bursting grass pollens. Additional biogenic volatile organic compounds (BVOCs) are identified here. Essential oils' BVOCs are inhaled from plants, oil diffusers, candles, room "fresheners", perfumes, and hygiene products. Claims of BVOC "safety" for sensitive respiratory systems are questioned. Methods: Fourteen volunteers, of mixed-age and gender, with seasonal asthma recorded peak expiratory flow (PEF) and 11 symptom scores. BVOCs were collected on Tenax tubes from ambient air in autumn and spring, as were live flower emissions, before and after a thunderstorm. Gas chromatography-mass spectrometry analysis identified frequently occurring BVOCs. Air spora, meteorological, outdoor air pollution variables, and BVOCs predict respiratory symptoms in univariate linear regression models, seasonally. Results: Increased pinene, camphor, linalool, linalyl acetate, benzaldehyde, and benzoic acid predict respiratory symptoms, including reduced PEF, and increased nasal congestion; day length, atmospheric pressure and temperature predict symptoms in both seasons, differently; other variables predict a range of symptoms (0.0001≤p≤0.05). Thunder predicts different BVOC emissions in spring, compared to autumn (p≤0.05). An uncut Grevillea flower emitted linalool and hexenal before a storm; the latter is also emitted from cut grass. Increased nitrogen oxides and pinene in autumn may combine to form harmful oxidation products. Conclusion: This research supports BVOCs as contributors to seasonal asthma and allergic rhinitis, and "thunderstorm" asthma. Pinene emissions from Myrtaceae species (Eucalyptus, Melaleuca, Leptospermum, Callistemon), Brassicaceae (canola), and conifers, worldwide, may induce respiratory inflammation and maintain it, by inhibiting eosinophilic apoptosis. Widely used essential oil products containing BVOCs, like linalool, are associated here with respiratory symptoms. Lagged responses suggest that users' cognitive associations between exposure and response are unlikely, increasing potential for impaired health for vulnerable children.