Allergenic pollen and pollen allergy in Europe

Direct detection of 3-nitrotyrosine reveals the nitration of proteins in laboratory exposure and ambient aerosols

Tyrosine residues in proteins can be nitrated to form 3-nitrotyrosine (3-NT) under the influence of ozone (O3) and nitrogen dioxide (NO2) in the air, which may introduce health impacts. A selective and sensitive enzyme-linked-immunoassay (ELISA) method was developed to determine 3-NT in modified model protein (bovine serum albumin, BSA) and ambient aerosol samples. The nitration degrees (NDs) of BSA in the exposure experiments with different durations were detected by both the ELISA and spectrophotometric methods (i.e., NDELISA and NDSEC-PDA), which show good coincidence. The kinetic investigation by both ΔNDELISA and ΔNDSEC-PDA in the exposure experiments shows that the rate coefficients (k) of the pseudo-first-order kinetic rate reactions of protein nitration were comparable. These results indicate that direct detection of 3-NT by the ELISA method can be applied for laboratory exposure samples analysis for kinetic studies. Based on the selective detection of 3-NT, NDELISA provides a promising measure for the assessment of ND in model proteins. 3-NT was also measured in PM2.5 samples in summer in Guangzhou, southern China, ranging from 10.1 to 404 pg/m3, providing clear evidence of protein nitration in ambient aerosols. We further proposed that 3-NT/protein can be used as a proxy to evaluate protein nitration in ambient aerosols. A significant correlation was observed between 3-NT/protein and O3, confirming the crucial role of O3 in protein nitration. Our results show that the direct detection of 3-NT by the ELISA method can be more widely applied in the laboratory and field-based studies for understanding the mechanisms of protein nitration.

Influence of ENSO, droughts, and temperature rise on pollen and pollen seasons in Australia

The concentration of pollen in the atmosphere is shaped by complex interactions between meteorology, climate, land use and human activities. Understanding these factors is crucial for allergy and asthma sufferers to better manage their conditions. This study examines the influence of weather and climate variables on pollen concentrations and pollen seasons in three Australian cities, using over 13, 16 and 32 years of long-term pollen data. El Niño Southern Oscillation (ENSO), drought, rainfall and vegetation index are among the major variables considered in the study. Grass pollen concentration (seasonal average) increased in Canberra (∼200 % per decade) and Sydney (∼34 % per decade) and likely decreased in Melbourne (∼13 % per decade). Melbourne showed an earlier onset and longer duration of the core grass pollen season. Long-term maximum temperature increased in Melbourne and Sydney while decreased in Canberra during the study years. Long-term daily pollen concentrations depicted a decreasing trend in Melbourne (p < 0.01) and increasing in Sydney (p < 0.01) and Canberra (p < 0.01). Daily maximum temperature had positive associations with daily pollen concentrations, while daily rainfall and humidity were negatively associated. Interannual variability in grass and other pollen concentrations was influenced by large-scale climate phenomena (ENSO cycle, Indian Ocean Dipole). Differential impacts were seen among grass and other pollen during drought and non-drought years in Melbourne. Spring rainfall (r = 0.5-0.7) and EVI (r = 0.3-0.9) had positive correlations with seasonal grass pollen. The findings from this study provide valuable insights for healthcare, scientific community and urban planning activities, especially in managing the health risks posed by allergenic pollen in a changing climate.

Interactions among Cupressaceae pollen, air pollutants and meteorology in the urban and suburban areas of Beijing, China

Atmospheric pollutants alter the physicochemical properties of pollen allergens, and raise a high risk of co-exposure to more aeroallergens in the allergic population. It is necessary to reveal the relationships between them and the impacts of meteorology on them both. Herein, synchronous data of aerobiology, pollution and meteorology at the same location are used to investigate the correlation between Cupressaceae pollen (major allergen in Norther China) and atmospheric pollutants, and their association with meteorological factors at different timescales in the urban and suburban areas of Beijing, China. In this research, the correlation between allergenic pollen, air pollutants and meteorological factors may display distinct patterns at daily and hourly timescales. Daily concentration of Cupressaceae pollen was positively correlated with PM2.5 and O3. Hourly pollen concentration exhibited positive correlation with NOx and PM2.5 during high-pollen episodes. Increasing temperature and decreasing relative humidity after sunrise facilitate pollination, causing hourly pollen peak. Temperature exhibited a strong positive correlation with daily and hourly O3 concentrations. Highly humid conditions largely decreased allergenic pollen and O3 concentrations but increased NOx and PM2.5 concentrations. In the urban area, local winds considerably impacting on hourly pollen peaks were associated with high levels of NOx and PM2.5. Concentration weighted trajectory (CWT) results indicated that allergenic pollen and O3 may have some common potential source areas. This research will help us to get a better understanding of the linkage between allergenic pollen and air pollutants, and their dynamics under varying meteorological conditions, and provide effective support on addressing respiratory allergies on the risk of co-exposure for allergenic pollen and air pollutants in the urban and suburban areas of Beijing city.

Exposure to outdoor aerospora and associated respiratory health risks among adults in Potchefstroom, North-West province, South Africa

Background

Data on allergic rhinitis and respiratory health metrics are limited for South Africa, with grass pollen as a key outdoor aeroallergen. Exotic trees such as plane trees and ragweed produce highly allergenic pollen, dominating indigenous trees and weeds. Pollen allergy prevalence data is lacking in cities of North-West province such as Potchefstroom.

Objectives

This study aimed to (i) assess the prevalence of allergies to major aeroallergens, including Poaceae (grasses), Cupressus/Hesperocyparis (cypresses), Platanus (plane tree), Ulmus (elm), Quercus (oak), Betula (birch), Olea (olive), Artemisia (sagebrush), Amaranthus (amaranth), Plantago (plantain), Morus (mulberry), and Ambrosia (ragweed), along with fungal spores such as Alternaria, Cladosporium, and Penicillium/Aspergillus, and (ii) investigate the monthly incidence of major aeroallergens and reactivity levels in sensitized adults in Potchefstroom.

Methods

Skin prick tests (SPTs) were performed on 202 adults aged 18-64 years with confirmed allergic symptoms during a field campaign at North-West University (NWU)'s Potchefstroom campus. A test panel of grass, weed, tree, and fungal spore extracts previously identified via aerobiological monitoring was used. Symptom scores were recorded using ISAAC questionnaires; Spearman's statistical correlation between symptom frequency and monthly aeroallergen concentrations were analyzed.

Results

Among the participants, 184 (91%) exhibited positive SPT reactions: 104 (57%) are monosensitized to pollen, 45 (24%) to fungal spores, and 35 (19%) are polysensitized. Aeroallergen prevalence was higher in females (73%) than in males (27%). The most common pollen allergens were Cynodon dactylon (Bermuda grass) (85%), Zea mays (maize) (46%), Platanus spp. (plane tree) (35%), and Ulmus campestris (field elm) (33%). Among fungal spores, Alternaria was the most common (93%), followed by Cladosporium (27%). A significant and positive statistical correlation was found between allergic rhinitis symptoms and monthly pollen concentrations of Betula, Morus, Platanus, and Quercus.

Discussion & Conclusion

This pilot study linked aeroallergens detected in Potchefstroom with allergy profiles of local residents. The findings highlight the need for more comprehensive regional studies that integrate allergen testing with aerobiological data. Raising awareness and implementing health strategies are essential for managing allergic rhinitis in South Africa. More affordable and available SPTs kits, adapted to allergy prevalence in South Africa, are strongly suggested.

Comparative modeling approaches for predicting Olea and Quercus pollen seasons in Thessaloniki, Greece

In the Mediterranean region, Olive (Olea europaea L.) is a primary source of airborne allergenic pollen, while Quercus contribute substantial quantities of pollen grains to the atmosphere, posing significant challenges in predicting their Main Pollen Seasons (MPS). This study addresses these challenges through the application of various predictive methodologies, including Thermal Time (TT) models, which integrate chilling and heat requirements, along with Partial Least Squares Regression (PLS), and Temperature-Photoperiod (TP) models. Pollen data from 2016 to 2022 in Thessaloniki, Greece, and meteorological data from ERA5 ECMWF reanalysis were analyzed. The results indicate that the mean duration of the Olea MPS was 58 days, starting in early April and peaking in mid-May, while the Quercus MPS lasted 55 days, starting in late March and peaking on average on April 25th. The predictive models were generally effective for forecasting the MPS, with a combination of TT and PLS methods providing the most robust predictions. PLS regression analysis highlighted the significant impact of spring and preceding autumn temperatures on the MPS. The chilling period for both pollen taxa typically begins in late November to early December, ending around early January, with an average requirement of about 1187 chilling hours. The heating requirements of the different predicting approaches for the start of MPS varied from 435 °C to 1113 °C for Olea and 544 °C to 1081 °C for Quercus. The results emphasize the importance of localized studies in aerobiology for accurate MPS predictions, which are crucial for public health planning and allergen management.

Serological Investigations on Environmental Allergens Triggering Allergic Dermatitis in Dogs from Western Romania

This study focused on identifying the environmental allergens causing allergic dermatitis in 250 dogs from Western Romania. Among the 250 dogs tested, 43% (107) exhibited significant allergic reactions (IgE levels greater than 2 kU/L), particularly in Maltese, French Bulldogs, Golden Retrievers, and West Highland White Terriers. The highest reactivity was observed to house dust mites (Dermatophagoides farinae, 91%), rye pollen (45%), and flea allergen Ctef 1 (15%). Statistical analyses revealed significant correlations between breed, sex, and living environment. Males exhibited a higher susceptibility to allergies (p < 0.001), whereas dogs that spent most of their time indoors were significantly more susceptible to allergic diseases than their mostly outdoors counterparts (p < 0.05). Additionally, dogs under two years old, especially those on a dry food diet, had an elevated risk of developing allergies (p < 0.01). Clinical manifestations included pruritus (60%), otitis externa (42%), and specific skin lesions (66%). The study underscores the role of environmental and dietary factors in the development of allergies in dogs. However, financial limitations related to allergy testing kits restricted the sample size, highlighting the need for further, more comprehensive research to enhance the generalizability of these findings.

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.

Sensitization profiles to olive pollen allergens and allergic respiratory disease severity in patients from Jaén, Spain: A cross-sectional study

Objective

To determine the molecular sensitization profile of patients allergic to olive pollen and evaluate its correlation with the type and severity of the allergic respiratory disease (ARD).

Patients and methods

Observational, cross-sectional study including patients aged 5-55 years with seasonal ARD (rhinitis and/or asthma) due to olive pollen sensitization from the Jaén University Hospital (Jaén, Spain), an area with prolonged high olive pollen exposure. Specific IgE (sIgE) levels to Ole e 1, Ole e 7, and Ole e 9 and clinical variables were considered. ARD severity was categorized according to the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines (rhinitis) and the Guía Española para el Manejo del Asma (GEMAv4.2).

Results

We included 1111 patients (mean [SD] age: 23.4 [12.7] years, 47.7% female) with asthma (87.8%) and rhinitis (96.9%). Ole e 1 sensitization was the most prevalent (79.6%), followed by Ole e 7 (62.0%) and Ole e 9 (50.8%); 60.3% of patients were sensitized to more than 1 olive pollen allergen and 19.2% had negative sIgE results. Ole e 1, Ole e 7, and Ole e 9 sensitizations were associated with asthma diagnosis and severity (p < 0.001 for all), Ole e 7 sensitization with rhinitis diagnosis (p = 0.006), and Ole e 1 and Ole e 9 with rhinitis severity (p = 0.007 and p = 0.006, respectively). The Ole e 1, Ole e 7, and Ole e 9 triple sensitization profile was associated with asthma diagnosis (p < 0.001) and severity (p = 0.029), and with rhinitis severity (p = 0.009).

Conclusion

Sensitizations to the olive pollen allergens Ole e 7 and Ole e 9 are prevalent in areas with prolonged high pollen exposure and become major allergens together with Ole e 1. In these areas, a considerable proportion of patients allergic to olive pollen have negative sIgE results. Triple sensitization to Ole e 1, Ole e 7, and Ole e 9 is associated with ARD severity and asthma diagnosis. The sensitization profiles based on molecular diagnosis (MD) may affect decisions regarding allergen immunotherapy treatment.

Short-course subcutaneous treatment with birch pollen allergoids greatly improves symptom and medication scores in birch allergy

BACKGROUND

Subcutaneous immunotherapy has emerged as an effective option for treating allergic diseases. Here, we assessed the clinical impact of the mannan-conjugated birch pollen polymerized allergoid T502 in birch pollen-induced allergic rhinoconjunctivitis.

METHODS

In this prospective, randomized, double-blind placebo-controlled phase III trial, 298 birch pollen-allergic adult patients were treated across 28 trial sites in Germany. Patients received either placebo or 23,000 mTU T502 subcutaneously over five pre-seasonal visits. Efficacy was assessed by comparing the combined symptom and medication score (CSMS) between placebo and T502 during the peak birch pollen season 2022. Safety, tolerability and immunologic effects were also analyzed.

RESULTS

During the peak birch pollen season, the median CSMS of the T502 group was reduced by 33% (p = 0.002) compared to placebo. The median daily symptom score and daily medication score were reduced by 30.4% (p < 0.001) and 56.3% (p = 0.045), respectively. Health related quality of life improved as reflected by reduction of RQLQ values by 31.5% (p < 0.0001). Production of Bet v 1 sIgG4 and Bet v 1 sIgG increased up to 6.2-fold and 3-fold respectively in the T502 group (p < 0.0001). The sIgE/sIgG4 ratio was strongly reduced in the T502 group at V7 (-62.9%, p < 0.0001). No fatalities nor serious adverse events were reported. In total, 16 systemic allergic reactions occurred (Grade I/II).

CONCLUSIONS

Treatment with T502 significantly reduced symptoms and medication need in rhinoconjunctivitis patients. The treatment is well tolerated and safe.

Ear, nose and throat disorders and international travel

BACKGROUND

Disorders of the ear, nose and throat may be the most commonly occurring pre-existing health condition in international travellers. Despite their high incidence, there is limited guidance for travellers and their clinicians on their prevention and management. This narrative review addresses this deficit by compiling and discussing available evidence on this neglected subject.

METHODS

A comprehensive review of the literature was undertaken using Medine and Scopus databases and multiple combinations of relevant MeSH search terms. Further references were obtained from focused searches on specific issues and manual review of the reference lists of articles obtained from the primary search.

RESULTS

Nasal congestion or discharge are among the most common complaints amongst travellers and various causes are reviewed. Changes in elevation result in a pressure differential between the atmospheric pressure and the middle ear and paranasal sinuses. The effects of air travel, recreational high-altitude exposure and diving are considered. Various causes of epistaxis in travellers such as cold air exposure and recreational cocaine use are discussed. The aetiology of a discharging ear in travellers includes otitis externa. The most frequently described travel-specific aetiology of dizziness is motion sickness while mal de debarquement is a specific subtype which affects travellers and is most commonly associated with sea travel. Surgical tourism for treatment of ear, nose and throat pathology is well established and various precautions are presented for post-operative travel. Obstructive sleep apnoea is discussed from the perspective of international travel. The challenges facing travellers with hearing impairment are explored.

CONCLUSIONS

This review critically discusses the prevention, diagnosis, and management of acute and chronic ENT conditions in the travelling population. Several areas of inquiry are highlighted that require further investigation. Close communication between ENT specialists and travel medicine practitioners is recommended in the preparation of selected patients for international travel.

Structural and Stability Analysis of GRP Family Allergens Pru p 7 and Cry j 7, Which Cause Pollen and Food Allergy Syndrome

Cry j 7 is a 7 kDa cysteine-rich gibberellin regulatory protein (GRP) with six disulfide bonds. It was isolated from Japanese cedar as the pollen allergen in this study. It exhibits cross-reactivity with food allergens such as Pru p 7 from peach and causes pollen-food allergy syndrome (PFAS). In this work, recombinant Cry j 7 and Pru p 7 were successfully overexpressed using Pichia pastoris in a high-cell-density fermentation culture, and pure proteins were purified by reverse-phase HPLC. The characterization of Cry j 7 and Pru p 7 were performed by MS, CD, and 1H-NMR experiments to confirm the correct native conformation of Cry j 7 as well as Pru p 7. When compared, the results showed that Cry j 7 exhibits excellent stability in disulfide linkages and preserves its original structure up to 90 °C in various pH buffers in comparison to Pru p 7. Notably, NMR analyses indicated the greater mobility in the α-helix and loop regions of S38-C47 in Pru p 7 compared to those of Cry j 7. Furthermore, our results showed that the sensitivity of Cry j 7 to enzyme digestion differed from that of Pru p 7: Cry j 7 was more susceptible to proteolysis, while Pru p 7 displayed better resistance in the gastrointestinal tract. These variations in structural stability and sensitivity to proteolysis provide valuable insights into the allergenicity within the GRP family.

Prevalence of immunoglobulin E sensitisation to mites and pollens in 25,451 French dogs from 2016 to 2022

BACKGROUND

Canine atopic dermatitis (cAD) is a common skin disorder in dogs, wherein allergens are presumed to exert a significant influence. The prevalence of allergen sensitisation in dogs with suspected cAD remains inadequately investigated in France.

HYPOTHESIS/OBJECTIVES

This study aimed to analyse allergen-specific immunoglobulin (Ig)E test results from French dogs with suspected cAD, exploring potential risk factors influencing sensitisation.

ANIMALS

The study included 25,451 client-owned dogs presented with clinical signs of cAD between January 2016 and December 2022. The study population consisted of 226 pure breeds and 915 cross-bred dogs of both sexes, with a mean age of 4.4 (±2.8) years.

MATERIALS AND METHODS

Data collection involved the compilation of results from canine serological allergen-specific IgE ELISA tests, using a 23 allergen composite panel. The influence of breed, sex, age, geographical area and sampling season on IgE test outcomes subsequently was analysed.

RESULTS

Of the 25,451 analysed samples, 75.6% exhibited significant serum IgE concentrations in response to at least one of the tested allergens, with 67.9% testing positive for mites and 39.8% for pollens. Breed, sex, age, geographical area and sampling season were identified as significant risk factors influencing sensitisation patterns.

CONCLUSIONS AND CLINICAL RELEVANCE

This study provides insights into the prevalence and risk factors associated with allergen sensitisation in dogs with suspected cAD. Understanding these factors is crucial for effective diagnosis and tailored management strategies in veterinary practice. The findings underscore the need for personalised approaches in addressing cAD, considering individual patient characteristics.

Urban Greening and Pollen Allergy: Balancing Health and Environmental Sustainability

Urban living requires a careful balance between human health and environmental sustainability when selecting urban vegetation. Public gardens and green roofs offer significant environmental benefits, including air filtration, exposure to health-associated microbiota, and mitigation of the urban heat island effect. However, prioritizing allergy-friendly species is crucial to prevent the exacerbation of pollen allergies. This review highlights 3 primary criteria for selecting vegetation that supports these ecosystem services while minimizing allergy risks. First, reducing the use of many wind-pollinated plants, such as birch trees and grasses, is crucial due to their high pollen production and cross-reactivity with other species, which can exacerbate allergies. In contrast, insect-pollinated plants are generally safer for allergy sufferers. Secondly, cultivating multispecies plant communities with minimal maintenance supports habitats for microbiota and invertebrates, further providing ecosystem services. Lastly, balancing plant gender ratios in urban spaces can help control pollen levels. Together these criteria provide a framework for urban planners to create green spaces that are both environmentally beneficial and allergy friendly. Although this review focuses on European data, the principles discussed have global relevance, reinforcing the need to integrate environmental sustainability with public health considerations in urban planning. Future studies should also investigate the health impacts of plant volatile emissions, explore heat-resistant plant varieties, and assess the ecological risks of invasive species to support sustainable, allergy-friendly urban environments.

Airborne pollen concentrations overpass expectations in the tropical city of Medellín, Colombia

Aerobiology in the tropics is still a science in development, where very little about their dynamics is known. Airborne pollen concentrations in the city of Medellín (Colombia) were measured using a Hirst-type sampler and correlated with meteorological parameters (relative humidity, rainfall, temperature, wind speed, and wind direction, this last analyzed by using circular statistics). Sampling was conducted over three years (2019-2022), and pollen grains were detected on all days of sampling, at higher concentrations than expected for tropical conditions. The highest pollen concentrations were observed from December to January and July-August, corresponding to the months with the lowest rainfall, which sheds light about how La Niña phenomena influenced pollen concentrations during the sampling period. The Main Pollen Season (MPS) ranged in length from 277 to 342 days. The highest intra-diurnal peaks pollen concentrations occurred around noon, whilst something very different and rarely reported occurs with Cecropia, which is much more abundant at night, from 20:00 to 1:00 h. Circular statistics revealed statistically significant wind direction patterns from SW, matching the same intra-diurnal pollen variations. This work helps to complete the blurred situation of the Aerobiology in the Neotropics and the dynamics of particles in the tropical atmosphere, being a first step towards the construction of pollen calendars to help pollen sufferers to mitigate symptoms.

Trends in land cover and in pollen concentration of Quercus genus in Alentejo, Portugal: Effects of climate change and health impacts

Mediterranean forests dominated by Quercus species are of great ecological and economic value. The Quercus pollen season, peaking in April, varies in concentration due to geographical and climatic factors and has a remarkable allergenic potential. This study investigates Quercus trends in the Alentejo region of Portugal and examines the influence of meteorological parameters on DPC, PSD and SPIn, as well as the impact on allergic respiratory disease. The results show a progressive increase in Quercus Forest area from 1995 to 2018. Temperature and Precipitation are a key factor influencing pollen concentration, especially before peak of pollen season and prior to the pollen season. Particularly prior to the season, the precipitation of t-6 before influence, significantly, the pollen production. On the other hand, Global Srad and RH determine the beginning of the season. Using quartile-based categorization and multivariate statistical analysis, we identified years and scenarios within the IPCC projections where meteorological conditions influence may SPIn production. The study found a statistically significant correlation between high Quercus pollen concentrations in April and increased antihistamine sales. These findings are crucial for enhancing pollen forecast models and early warning systems.

Importance of the quality management of aerobiological monitoring networks: The case study of Madrid Region in Spain

Interest in biological air quality monitoring is rising, and updated public information is increasingly demanded by stakeholders in the case of airborne pollen, which requires maintaining high standards of data quality. The number of aerobiological stations worldwide is continuously growing, and quality management is becoming more complex with the increase in the scale of aerobiological networks. Quality control exercises are crucial for maintaining the quality of the data used in the pollen monitoring routine over time. In this study we show the results of an intercomparison test among technicians in the Madrid Region Palynological Network in central Spain in order to identify potential sources of error during the pollen analysis. The findings of this intercomparison exercise indicated very high-quality pollen data based on two different proficiency tests: i) the technicians' analysis of common samples with the light microscopes used in the routine pollen analysis; and ii) the analysis of common samples with all technicians using the same light microscope. A few specific remarkable errors were detected (i.e., those whose Absolute Error > |10| and Relative Error > |20 %|), such as confusion by four participants between Quercus vs. Acer and Quercus vs. Platanus pollen. Since the pollen analysis routine requires very experienced professionals, we believe it is essential to provide adequate training programmes for pollen analysis and the specific identification of these problematic pollen types. High-quality environmental data is crucial for sharing with regional, national and continental networks to ensure applicability, reproducibility and integration in large-scale studies.

Increased rupture of cypress pollen type due to atmospheric water in central and southeastern Spain

This study aims to investigate the meteorological variables determining Cupressaceae pollen grain disruption in the environment. A parallel sampling of pollen grains and disrupted Cupressaceae pollen grains was performed in six cities using two Spanish aerobiological networks. The pollen concentrations, disrupted pollen concentrations, percentage of disrupted pollen and number of days when the percentage of disrupted pollen was above or equal to 50 % were quantified during two pollen seasons. The concentrations were determined following the standardised method EN 16868. Results show that the concentrations of pollen grains and disrupted pollen grains were not determined by geographical features and rarely by bioclimatic variables or indexes but by the ornamental use of the specimens in the vicinity of the pollen sampler, highlighting the possibility of using management practices to reduce exposure to allergens in the cities. African dust outbreaks coincided with higher concentrations of pollen grains and disrupted pollen grains, but the reduced percentage of disrupted pollen grains pointed to a non-causal relationship with long-distance transport. The effect of wind and maximum gusts remained negligible. The triggering factor for pollen disruption was the amount of water in the atmosphere, mainly reported as relative humidity. Rainfall increased the effect of disruption due to pollen grain swelling caused by its wash-out effect. The higher the relative humidity, the higher the disrupted pollen concentrations. This aligns with the mechanism of Cupressaceae reproduction since the family needs a water medium in the form of pollination droplets for the pollination tube to develop and the pollen grain to perform its biological function. Therefore, people that develop allergic symptoms to Cupresaceae pollen should avoid exposure during days with high relative humidity in the main pollen season.

Common pollen and related allergen components in patients with allergic diseases in the Beijing area

Background

Pollen is the most common outdoor allergen that causes allergic rhinitis and asthma, which seriously affects patient quality of life and extensive cross-reactivity occurs between pollen allergens.

Methods

The study enrolled 84 patients with respiratory allergies and at least one pollen allergy who visited the clinic. Specific-IgE was detected via immunoblotting in the sera of patients with positive respiratory allergies to pollen. IgE of the components and cross-reactive carbohydrate determinants (CCD) were evaluated using a fluorescence-encoded microsphere assay.

Results

Our results suggest that Artemisia absinthium, Artemisia vulgaris, Humulus scandens, Amaranthus, Parietaria micrantha allergies are most common in the northern region, and that weed pollen remains the major pollen allergen in the northern region. Among the different age groups, the positive rate of Platanus pollen allergens was significantly higher in patients ≤18 years of age than in those aged >18 years (55.56% vs. 9.17%, χ² = 0.55, p < 0.027). Patients with allergic rhinitis and asthma had an increased positive rate for Betula pollen allergen (20.00% vs. 37.93 χ² = 7.87, p = 0.005) and Platanus pollen allergen (27.27% vs. 51.72%, χ² = 11.05, p = 0.0008) than those with allergic rhinitis alone, although the allergen positivity rate did not significantly differ between sexes. In addition, the positivity of sIgE of allergen components did not reveal a correlation with clinical symptoms and anti-CCD IgE positivity was 1.19% (1/84) among all patients.

Conclusion

The study found the distribution characteristics of common pollen allergens in Beijing among patients of different ages and genders and with different allergic diseases, as well as the relationship between pollen allergen components and symptoms. The positivity rate of CCD for respiratory allergic diseases in Beijing was not high as well.

Comparison of Olea pollen sampling between gravimetric and volumetric traps (NW of Morocco)

Olea pollen is considered one of the most critical causes of respiratory allergic disease in the Mediterranean region, contributing to different symptoms in allergic sufferers. Due to the high increase in the prevalence of olive pollen caused by the expansion of cultivated areas especially in the Mediterranean region, the aim of this study was to examine the Olea pollen sampling efficiency between gravimetric and volumetric pollen traps over the period 2018-2022. Our data demonstrated that Olea pollen season start-date was generally recorded earlier with volumetric trap than shown with gravimetric method. Moreover, the peak dates occurred mainly in May for the years studied. Across the entire period, the greatest pollen concentrations were reached in the week 11th and >60 % of the total Olea pollen were already reached after the ninth week of sampling in 2020. In general, the evolution of pollen sampling for both methods demonstrates similar temporal development. Variations in the seasonal pollen integral could be attributed to the elevation above ground level at which the traps were placed, exposure to regional winds, the influence of long-range transported pollen and the mode of pollen transport. The findings indicate that the gravimetric method was equally practical as the volumetric method in estimating airborne pollen.

Decongestant Effect of "Coldamaris Akut", a Carrageenan- and Sorbitol-Containing Nasal Spray in Seasonal Allergic Rhinitis

Purpose

This study aimed to develop a hyperosmolar, barrier-forming nasal spray based on carrageenan and sorbitol, and to demonstrate its decongestant effect in the context of allergic rhinitis (AR).

Methods

The efficacy of the nasal spray components was tested in vitro by barrier function, virus replication inhibition, and water absorption assays. The decongestant effectiveness was assessed in a randomized, controlled, crossover environmental chamber trial, where participants with a history of seasonal grass pollen AR were exposed to grass pollen allergens under controlled conditions. Forty-one adults were randomized to receive either carrageenan- and sorbitol-containing nasal spray (CS) or saline solution (SS). After 1 week, participants repeated the exposure with the treatment they had not received before. The primary efficacy endpoint was the mean change in nasal congestion symptom score (NCSS). Secondary efficacy endpoints were nasal airflow, nasal secretion, total nasal symptom score (TNSS), total ocular symptom score (TOSS) and total respiratory symptom score (TRSS).

Results

Preclinical assays demonstrated barrier-building, virus-blocking, and water-withdrawing properties of the CS components. In the clinical study, there was no significant difference in mean NCSS change from pre- to post-treatment between CS and SS. However, nasal airflow increased over time after treatment with CS, while it declined after SS, leading to a growing difference in airflow between CS and SS (p = 0.04 at 6:00 h). Mean nasal secretion over 2-6 h was reduced by ~25% after CS (p = 0.003) compared to pre-treatment, while it was reduced by only ~16% after SS (p = 0.137). No significant differences in TNSS, TOSS and TRSS were observed between CS and SS.

Conclusion

CS improves nasal airflow and reduces nasal secretion in adults with AR. We propose CS as a safe and effective adjuvant to baseline pharmacological treatments.

Trial Registration

NCT04532762.

Exploring the influence of meteorological conditions on the variability of olive pollen intradiurnal patterns: Differences between pre- and post-peak periods

Olive trees hold a significant economical, ecological and ornamental value, especially in the Mediterranean area. It is a wind-pollinated species emitting huge quantities of pollen with a high degree of allergenic sensitization. Andalusia region (southern Spain), where 15 % of the global olive tree population is cultivated, present a high density of this crop, reaching daily airborne olive pollen concentrations up to 6.000 pollen/m3. Although daily variations during the pollen season have been widely investigated in bibliography, factors influencing the intradiurnal dynamics of olive pollen concentrations remains underexplored in aerobiology. The present paper focuses on it, characterizing main intradiurnal patterns, identifying potential pollen source areas and the influence of wind dynamics on Córdoba city olive pollen data. The results reveal the presence of different pollen peaks at various hours of the day, depending on the stage of the pollen season (pre- and post-peak) and wind dynamics. Nevertheless, the main one is detected at midday during the pre-peak season, with secondary peaks at night, morning and late afternoon. A thorough examination of wind dynamics highlighted the significant influence of distant and local sources on the hourly pollen peaks and hence, on intradiurnal patterns. The analysis of the intradiurnal pattern associated with different air mass patterns demonstrated a considerable variability in the occurrence of peak concentrations and hence, in the contribution of sources. The characterization of surface winds confirms the substantial differences in the dynamics of atmospheric transport processes that influence the primary intradiurnal patterns of olive pollen in this region.

Inverse Trend Between Tree Pollen and Fungal Concentrations With Allergic Sensitization Rates in Seoul for 25 Years

A growing number of individuals are developing allergic diseases due to pollen exposure. Seasonal variations and increased pollen concentrations have occurred with the increased rates of allergic sensitization among both children and adults. Temperature significantly influences pollination, particularly in spring- and early summer-flowering plants, with weather conditions affecting pollen allergen levels. Human activities, including agriculture and deforestation, increase carbon emissions, leading to higher atmospheric CO₂ levels that may enhance allergenic plant productivity. Climate change affects the range of allergenic plant species and length of pollen season. Studies indicate that higher CO₂ and temperature levels are linked to increased pollen concentrations and allergenicity, whereas atmospheric fungal concentrations have declined annually over the past 25 years. Despite more intense precipitation in summer and autumn, the number of rainy days has decreased across all seasons. This concentration of rainfall over shorter periods likely prolongs the dry season and shortens the period of fungal sporulation. Future climate changes, including atmospheric dryness, drought, and desertification could further decrease allergenic fungal sporulation. It remains unclear whether the inverse relationship between pollen and fungal concentrations and distributions directly results from climate change. It is crucial to evaluate the patterns of aeroallergens and their associated health risks.

Synergistic control of urban heat island and urban pollution island effects using green infrastructure

Urban heat island (UHI) and urban pollution island (UPI) effects are two major challenges that affect the liveability and sustainability of cities under the circumstance of climate change. However, existing studies mostly addressed them separately. Urban green infrastructure offers nature-based solutions to alleviate urban heat, enhance air quality and promote sustainability. This review paper provides a comprehensive synthesis of the roles of urban green spaces, street trees, street hedges, green roofs and vertical greenery in mitigating UHI and UPI effects. These types of green infrastructure can promote the thermal environment and air quality, but also potentially lead to conflicting impacts. Medium-sized urban green spaces are recommended for heat mitigation because they can provide a balance between cooling efficiency and magnitude. Conversely, street trees pose a complex challenge since they can provide cooling through shading and evapotranspiration while hindering pollutant dispersion due to reduced air ventilation. Integrated research that considers simultaneous UHI and UPI mitigation using green infrastructure, their interaction with building features, and the urban geographical environment is crucial to inform urban planning and maximize the benefits of green infrastructure installations.

Forecast models for start and peak dates of Poaceae pollen season in Tétouan (NW Morocco) using multiple regression analysis

Poaceae pollen is one of the most widespread sources of aeroallergens in the world. The aim of this study is to build predictive models for the pollen season start day (PSsd) and peak dates of the Poaceae pollen season and thus give an overview of the climatic parameters that have the greatest influence. In Tétouan, sampling was carried out using a volumetric spore trap of the Burkard Hirst type. The relationships between the PSsd, peak dates and meteorological parameters were determined using correlation analysis. The models were constructed using multiple regression analysis with data from 2008 to 2019 and tested on data from 2022. The PSsd was especially significantly influenced by minimum temperature during winter and precipitation in the autumn of the previous year. The peak dates were significantly correlated with precipitation in January, March and April, but not with temperature. Three models were obtained for each of the season's parameters; the most accurate model for the PSsd explained a variability of 61% and includes as main predictors rainfall from the autumn of the previous year and the mean daily average temperature from 23 February to 8 March. The two most efficient peak dates models included precipitation in January and April as the main predictor variables, and explained greater variability (87 and 88%). Precipitation in autumn and the mean daily and the sum of minimum temperature in winter, showed significant decreasing tendencies. However, the PSsd trend delay was not statistically significant. This study draws the importance of the weather during preseason for grass pollen production and emphasises the usefulness of the models for allergic patients to take preventive measures and for healthcare professionals in allergy therapy.

Profile of cross-reactivity to common pollen allergens in Northwest China based on component resolved diagnosis

The prevalence of allergic diseases such as Allergic Rhinitis and Asthma is steadily increasing globally, with pollen allergy being one of the most significant sensitizing factors. However, the cross-reactivity of different pollen allergies remains unclear, posing challenges in the diagnosis and treatment of individuals with multiple sensitivities. In this study, the Component Resolved Diagnosis technique was performed to simultaneously measure the specific IgE concentrations of 52 patients against Art v and its components (Art v 1), Phl p and its components (Phl p 1, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 12), Bet v and its components (Bet v 1, Bet v 2), Amb a and its component (Amb a 1), and Amb p. Additionally, sIgE inhibition tests were conducted by Art v, Phl p, and Bet v extracts. Among Art v-positive patients, 64.6% showed positivity for Art v 1. In Phl p-positive patients, Phl p 12 had the highest positivity rate (75.0%). Among Bet v-positive patients, 75.6% exhibited positivity for Bet v 2, whereas for Amb a and Amb p-positive patients, 23.7% and 29.0% respectively showed positivity for Amb a 1. The sIgE inhibition assays results revealed that Art v extract had inhibition rates greater than 73.2% against Phl p and its component Phl p 12, as well as Bet v and its component Bet v 2. Simultaneously, Phl p extract showed inhibition rates of 80.70-89.87% against Phl p 12, Bet v and Bet v 2. Bet v extract showed inhibition rates ranging from 21.9 to 59.8% against Phl p and Bet v 2, with a better inhibition rate (76.80%) against Phl p 12. In conclusion, Art v 1 is identified as the principal component of Art v. The profilin proteins of Phl p and Bet v (Phl p 12 and Bet v 2), are implicated as potential cross-reactive elements contributing to polysensitization in patients with respiratory allergies in the Northwest region of China. This cross-reactivity leads to a shared sensitization mechanism among pollen allergens such as Art v, Phl p, and Bet v.

European pollen reanalysis, 1980-2022, for alder, birch, and olive

The dataset presents a 43 year-long reanalysis of pollen seasons for three major allergenic genera of trees in Europe: alder (Alnus), birch (Betula), and olive (Olea). Driven by the meteorological reanalysis ERA5, the atmospheric composition model SILAM predicted the flowering period and calculated the Europe-wide dispersion pattern of pollen for the years 1980-2022. The model applied an extended 4-dimensional variational data assimilation of in-situ observations of aerobiological networks in 34 European countries to reproduce the inter-annual variability and trends of pollen production and distribution. The control variable of the assimilation procedure was the total pollen release during each flowering season, implemented as an annual correction factor to the mean pollen production. The dataset was designed as an input to studies on climate-induced and anthropogenically driven changes in the European vegetation, biodiversity monitoring, bioaerosol modelling and assessment, as well as, in combination with intra-seasonal observations, for health-related applications.

Pollen effects in a changing climate: Ragweed pollen exposure and sleepiness in immunotherapy patients of a Southeastern Michigan allergy clinic

Allergic rhino-conjunctivitis (AR) is a globally relevant health disorder characterized by sneezing, rhinorrhea and sleep disturbance. Ragweed (Ambrosia artemisiifolia) is a plant common to North America and an important allergen. Coarse methods of measuring airborne pollen counts are used to predict seasonal allergy symptoms. This research used a longitudinal study design with a novel, model-based raster of predicted pollen counts to test associations with self-reported symptoms of AR collected from patients receiving immunotherapy for pollen allergies at an allergy clinic. Researchers visited a clinic six times over three weeks. Immunotherapy patients were asked to fill out a brief intake survey on allergic and symptomatic profiles, daytime sleepiness, housing quality, and demographics. Participants responded to a daily, emailed survey on sleepiness and asthma symptoms for 21 days. Using the date and location of responses, ragweed pollen counts were extracted from a prognostic, model based raster (25km pixels). Lag associations of pollen counts with sleepiness were tested using a logistic regression model , adjusted for housing and demographic characteristics, in a distributed lag non-linear model (DLNM) framework. 49 people participated in the study. 26 (52%) were female. The mean age was 37.9 years. Asthma/allergy symptoms were not associated with ragweed pollen but sleepiness was highest two days after exposure (Estimate: 0.33 [0.04,0.62]). Subjects traveled widely during the study period. Intense exposures to ragweed pollen may be associated with daytime sleepiness within small exposure windows. Model-based predicted pollen counts could be used to study health impacts of pollen in people with disease severe enough to receive immunotherapy. Daytime sleepiness can affect productivity and injury risk, and pollen season length and allergenicity may be increasing with climate change. Thus our results may have important implications for population health.

Diagnostic Workup in IgE-Mediated Allergy to Asteraceae Weed Pollen and Herbal Medicine Products in Europe

Anemophilous weeds from the Asteraceae family are highly allergenic and represent a significant source of aeroallergens in late summer and autumn. Ragweed and mugwort pollen allergies have become a significant health burden in Europe. Some people with respiratory allergies to weed pollen may also suffer hypersensitivity reactions to herbal medicines obtained from certain cross-reactive plants in the Compositae family, such as chamomile, marigold, and purple coneflower. General physicians, ear, nose, and throat (ENT) specialists, and pulmonologists need to be familiar with the diagnostic tests used by allergists in clinical practice to support accurate diagnosis in such patients. Allergists must also be aware of the suggestions of the European Medicines Agency (EMA)'s Herbal Medicinal Products Committee and the broad spectrum of herbal therapies to educate their patients about potential risks.

Food-Pollen Cross-Reactivity and its Molecular Diagnosis in China

PURPOSE OF REVIEW

Plant-derived foods are one of the most common causative sources of food allergy in China, with a significant relationship to pollinosis. This review aims to provide a comprehensive overview of this food-pollen allergy syndrome and its molecular allergen diagnosis to better understand the cross-reactive basis.

RECENT FINDINGS

Food-pollen cross-reactivity has been mainly reported in Northern China, Artemisia pollen is the major related inhalant source, followed by tree pollen (Betula), while grass pollen plays a minor role. Pollen allergy is relatively low in Southern China, with allergies to grass pollen being more important than weed and tree pollens. Rosaceae fruits and legume seeds stand out as major related allergenic foods. Non-specific lipid transfer protein (nsLTP) has been found to be the most clinically relevant cross-reacting allergenic component, able to induce severe reactions. PR-10, profilin, defensin, chitinase, and gibberellin-regulated proteins are other important cross-reactive allergen molecules. Artemisia pollen can induce allergenic cross-reactions with a wide range of plant-derived foods in China, and spring tree pollens (Betula) are also important. nsLTP found in both pollen and plant-derived food is considered the most significant allergen in food pollen cross-reactivity. Component-resolved diagnosis with potential allergenic proteins is recommended to improve diagnostic accuracy and predict the potential risk of causing allergic symptoms.

Phenological Analysis of Grasses (Poaceae) in Comparison with Aerobiological Data in Moscow (Russia)

Grasses (Poaceae) produce large amounts of pollen and are among the main causes of pollinosis worldwide. Despite their morphological similarity, pollen grains of different grass species may have different allergenicities. Therefore, quantification of the roles of individual species in airborne pollen is an important task. There are very few studies on this topic, and none of them have been conducted in a temperate continental climate. Our study was carried out for three years (2020-2022) in the urban territory of Moscow (Russia) and aimed to understand what grass species contribute the most to the total pollen load of the atmosphere. The comparison of aerobiological and phenological data was based on calculating the phenological index, which is a combination of phenological parameters, pollen productivity of individual species, and their abundance. Our data showed that the decomposition of pollination curves based on the phenological index was sometimes very efficient but not always possible in temperate continental climates. The main reasons for disagreement between aerobiological and phenological data were weather conditions and lawn mowing. Not all grasses were equally important as sources of allergenic pollen. The greatest contribution to the pollen load at the beginning of the season in Moscow was made by Dactylis glomerata, and to a lesser extent by Phleum pratense and Festuca pratensis. These are the most common species, which are widespread throughout Europe. The contribution of minor components is insignificant.

Pollen-Food Allergy Syndrome: From Food Avoidance to Deciphering the Potential Cross-Reactivity between Pru p 3 and Ole e 7

BACKGROUND

Cross-reactivity between nonspecific lipid transfer proteins could cause anaphylaxis, further influencing food avoidance and nutrient deficiencies. The one affecting olive pollen (Ole e 7) and peach (Pru p 3) may underlie a variety of pollen-food syndromes, though a deep molecular analysis is necessary.

METHODS

Three Ole e 7-monosensitised patients (MON_OLE), three Pru p 3-monosensitised patients (MON_PRU) and three bisensitised patients (BI) were selected. For epitope mapping, both digested proteins were incubated with patient sera, and the captured IgE-bound peptides were characterised by LC-MS.

RESULTS

The analysis revealed two Ole e 7 epitopes and the three Pru p 3 epitopes previously described. Interestingly, the "KSALALVGNKV" Ole e 7 peptide was recognised by MON_OLE, BI and MON_PRU patients. Conversely, all patients recognised the "ISASTNCATVK" Pru p 3 peptide. Although complete sequence alignment between both proteins revealed 32.6% identity, local alignment considering seven residue fragments showed 50 and 57% identity when comparing "ISASTNCATVK" with Ole e 7 and "KSALALVGNKV" with Pru p 3.

CONCLUSIONS

This study mapped sIgE-Ole e 7-binding epitopes, paving the way for more precise diagnostic tools. Assuming non-significant sequence similarity, structural homology and shared key residues may underlie the potential cross-reactivity between Ole e 7 and Pru p 3 nsLTPs.

Main Airborne Pollen Species and Characteristics of Allergic Rhinitis Patients with Pollen-Related Allergies in 13 Northern Chinese Cities

Background

Pollen allergies have a high prevalence in northern China, whereas, the types of pollen allergens and population characteristics among different regions remain unclear.

Objective

To study the species and temporal distribution of the main allergenic pollen, as well as the characteristics of patients with pollen-related allergic rhinitis (AR) in different cities in northern China.

Methods

Pollen data were obtained from pollen-monitoring stations in 13 cities of northern China between 2020 and 2021. Questionnaire surveys and allergen testing were conducted in 494 patients with pollen-related allergies from Beijing in Central, Shenyang in Northeast, and Xi'an in Northwest China.

Results

In 13 cities of northern China, the main sources of pollen were cypress, poplar, elm, pine, birch and ash in spring, and mugwort, goosefoot, hop and ragweed in autumn. In Northwest China, the spring and autumn pollen periods started earlier and lasted longer than that in Central and Northeast China, and the pollen counts in autumn in was significantly higher than that in Central and Northeast China. Furthermore, the nasal, ocular and respiratory symptom and quality of life scores of AR patients in Northwest China were significantly higher than that in Central and Northeast China. 69.32-73.28% of patients had annual cost of anti-allergic medication between 500-5000 yuan. However, 40.93-48.86% of patients reported minor control of symptoms.

Conclusion

Our results can be used as a basis for developing effective prevention and management measures for patients with pollen-related allergy in these regions, including timely pollen monitoring, patient guidance on protective measures, early intervention, and specific immunotherapy, to improve pollen-related allergy management.

Polysensitisation is associated with more severe symptoms: The reality of patients with allergy

BACKGROUND

Studying the sensitisation profiles of patients with allergies allows for a deeper understanding of the disease which may facilitate the selection of the best-personalised allergen immunotherapy. This observational, cross-sectional, multicentre study aimed to demonstrate the heterogeneity of the German population with allergies by analysing specific immunoglobulin E (sIgE) patterns towards aeroallergens and exploring the relationship between sensitisation and clinical symptoms.

METHODS

In total, 500 patients with allergies from different regions of Germany were recruited based on their case histories, clinical allergic symptoms and skin prick test data for aeroallergens. Serum samples were analysed using ImmunoCAP assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens.

RESULTS

Most patients (81%) were polysensitised. Betula verrucosa pollen was the most common cause of sensitisation (59%), followed by Phleum pratense (58%) and Dermatophagoides pteronyssinus (44%). The highest prevalence rates of molecular allergens were observed for Bet v 1 (84%) from birch pollen, Phl p 1 from grass pollen (82%), Der p 2 (69%) from mites and Fel d 1 (69%) from cat. Polysensitisation was significantly associated with the presence of asthma and the severity of rhinitis symptoms.

CONCLUSIONS

Our findings show a high rate of polysensitisation and emphasise the importance of molecular diagnosis for more precise and comprehensive insights into sensitisation patterns and their association with clinical symptoms. These data may help improve personalised diagnosis and immunotherapy adapted to the needs of individual patients in the region.

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.

Ambient pollen exposure and pollen allergy symptom severity in the EPOCHAL study

BACKGROUND

Ambient pollen exposure causes nasal, ocular, and pulmonary symptoms in allergic individuals, but the shape of the exposure-response association is not well characterized. We evaluated this association and determined (1) whether symptom severity differs between subpopulations; (2) how the association changes over the course of the pollen season; and (3) which pollen exposure time lags affect symptoms.

METHODS

Adult study participants (n = 396) repeatedly scored severity of nasal, ocular, and pulmonary allergic symptoms, resulting in three composite symptom scores. We calculated hourly individually relevant pollen exposure to seven allergenic plants (alder, ash, birch, hazel, grasses, mugwort, and ragweed) considering personal sensitization and exposure time lags of up to 96 h. We fitted generalized additive mixed models, with a random personal intercept, adjusting for weather and air pollution as potential time-varying confounders.

RESULTS

We identified a clear nonlinear positive association between pollen exposure and ocular and nasal symptom severity in the pollen allergy group: Symptom severity increased steeply with increasing exposure initially, but attenuated beyond approximately 80 pollen/m3. We found no evidence of an exposure threshold, below which no symptoms occur. While recent pollen exposure in the last approximately 5 h affected symptoms most, associations lingered for up to 60 h. Grass pollen exposure (compared to tree pollen) and younger age (18-30 years, as opposed to 30-65 years) were both associated with higher nasal and ocular symptom severity.

CONCLUSIONS

The lack of a threshold and attenuated dose-response curve may have implications for pollen warning systems, which may be revised to include multiday pollen concentrations in the future.

Air pollution and climate change as grand challenges to sustainability

There is a cross-disciplinary link between air pollution, climate crisis, and sustainable lifestyle as they are the most complex struggles of the present century. This review takes an in-depth look at this relationship, considering carbon dioxide emissions primarily from the burning of fossil fuels as the main contributor to global warming and focusing on primary SLCPs such as methane and ground-level ozone. Such pollutants severely alter the climate through the generation of greenhouse gases. The discussion is extensive and includes best practices from conventional pollution control technologies to hi-tech alternatives, including electric vehicles, the use of renewables, and green decentralized solutions. It also addresses policy matters, such as imposing stricter emissions standards, setting stronger environmental regulations, and rethinking some economic measures. Besides that, new developments such as congestion charges, air ionization, solar-assisted cleaning systems, and photocatalytic materials are among the products discussed. These strategies differ in relation to the local conditions and therefore exhibit a varying effectiveness level, but they remain evident as a tool of pollution deterrence. This stresses the importance of holistic and inclusive approach in terms of engineering, policies, stakeholders, and ecological spheres to tackle.

Spatial Variation of Airborne Pollen Concentrations Locally around Brussels City, Belgium, during a Field Campaign in 2022-2023, Using the Automatic Sensor Beenose

As a growing part of the world population is suffering from pollen-induced allergies, increasing the number of pollen monitoring stations and developing new dedicated measurement networks has become a necessity. To this purpose, Beenose, a new automatic and relatively low-cost sensor, was developed to characterize and quantify the pollinic content of the air using multiangle light scattering. A field campaign was conducted at four locations around Brussels, Belgium, during summer 2022 and winter-spring 2023. First, the consistency was assessed between the automatic sensor and a collocated reference Hirst-type trap deployed at Ixelles, south-east of Brussels. Daily average total pollen concentrations provided by the two instruments showed a mean error of about 15%. Daily average pollen concentrations were also checked for a selection of pollen species and revealed Pearson and Spearman correlation coefficients ranging from 0.71 to 0.93. Subsequently, a study on the spatial variability of the pollen content around Brussels was conducted with Beenose sensors. The temporal evolution of daily average total pollen concentrations recorded at four sites were compared and showed strong variations from one location to another, up to a factor 10 over no more than a few kilometers apart. This variation is a consequence of multiple factors such as the local vegetation, the wind directions, the altitude of the measurement station, and the topology of the city. It is therefore highly necessary to multiply the number of measurement stations per city for a better evaluation of human exposure to pollen allergens and for more enhanced pollen allergy management.

Heterogenous Induction of Blocking Antibodies against Ragweed Allergen Molecules by Allergen Extract-Based Immunotherapy Vaccines

Currently, allergen-specific immunotherapy (AIT) for ragweed allergy is still based on natural allergen extracts. This study aimed to analyse the ability of four commercially available AIT vaccines (CLUSTOID, TYRO-SIT, POLLINEX Quattro Plus and Diater Depot) regarding their ability to induce IgG antibodies against ragweed pollen allergens in rabbits. Accordingly, the IgG reactivity of AIT-induced rabbit sera was tested for ten different ragweed pollen allergens (Amb a 1, 3, 4, 5, 6, 8, 9, 10, 11 and 12) by an ELISA. Furthermore, the ability of rabbit AIT-specific sera to block allergic patients' IgE binding to relevant ragweed allergens (Amb a 1, 4, 6, 8 and 11) and to inhibit allergen-induced basophil activation was evaluated by an IgE inhibition ELISA and a mediator release assay. Only two AIT vaccines (Diater Depot > CLUSTOID) induced relevant IgG antibody levels to the major ragweed allergen Amb a 1. The IgG responses induced by the AIT vaccines against the other ragweed allergens were low and highly heterogeneous. Interestingly, the kinetics of IgG responses were different among the AIT vaccines and even within one AIT vaccine (Diater Depot) for Amb a 1 (long-lasting) versus Amb a 8 and Amb a 11 (short-lived). This could be due to variations in allergen contents, the immunogenicity of the allergens, and different immunization protocols. The IgE inhibition experiments showed that rabbit AIT-specific sera containing high allergen-specific IgG levels were able to inhibit patients' IgE binding and prevent the mediator release with Diater Depot. The high levels of allergen-specific IgG levels were associated with their ability to prevent the recognition of allergens by patients' IgE and allergen-induced basophil activation, indicating that the measurement of allergen-induced IgG could be a useful surrogate marker for the immunological efficacy of vaccines. Accordingly, the results of our study may be helpful for the selection of personalized AIT vaccination strategies for ragweed-allergic patients.

The ancestral karyotype of the Heliantheae Alliance, herbicide resistance, and human allergens: Insights from the genomes of common and giant ragweed

Ambrosia artemisiifolia and Ambrosia trifida (Asteraceae) are important pest species and the two greatest sources of aeroallergens globally. Here, we took advantage of a hybrid to simplify genome assembly and present chromosome-level assemblies for both species. These assemblies show high levels of completeness with Benchmarking Universal Single-Copy Ortholog (BUSCO) scores of 94.5% for A. artemisiifolia and 96.1% for A. trifida and long terminal repeat (LTR) Assembly Index values of 26.6 and 23.6, respectively. The genomes were annotated using RNA data identifying 41,642 genes in A. artemisiifolia and 50,203 in A. trifida. More than half of the genome is composed of repetitive elements, with 62% in A. artemisiifolia and 69% in A. trifida. Single copies of herbicide resistance-associated genes PPX2L, HPPD, and ALS were found, while two copies of the EPSPS gene were identified; this latter observation may reveal a possible mechanism of resistance to the herbicide glyphosate. Ten of the 12 main allergenicity genes were also localized, some forming clusters with several copies, especially in A. artemisiifolia. The evolution of genome structure has differed among these two species. The genome of A. trifida has undergone greater rearrangement, possibly the result of chromoplexy. In contrast, the genome of A. artemisiifolia retains a structure that makes the allotetraploidization of the most recent common ancestor of the Heliantheae Alliance the clearest feature of its genome. When compared to other Heliantheae Alliance species, this allowed us to reconstruct the common ancestor's karyotype-a key step for furthering of our understanding of the evolution and diversification of this economically and allergenically important group.

IgE to cyclophilins in pollen-allergic children: Epidemiologic, clinical, and diagnostic relevance of a neglected panallergen

BACKGROUND

Cyclophilins are ubiquitous panallergens whose epidemiologic, diagnostic, and clinical relevance is largely unknown and whose sensitization is rarely examined in routine allergy practice.

OBJECTIVE

We investigated the epidemiologic, diagnostic, and clinical relevance of cyclophilins in seasonal allergic rhinitis and its comorbidities.

METHODS

We examined a random sample of 253 (25%) of 1263 Italian children with seasonal allergic rhinitis from the Panallergens in Pediatrics (PAN-PED) cohort with characterized disease phenotypes. Nested studies of sensitization prevalence, correlation, and allergen extract inhibition were performed in patients sensitized to birch pollen extract but lacking IgE to Bet v 1/2/4 (74/1263) or with highest serum level of IgE to Bet v 1 (26/1263); and in patients with sensitization to various extracts (ragweed, mugwort, pellitory, Plantago, and plane tree), but not to their respective major allergenic molecule, profilins, and polcalcins. IgE to cyclophilin was detected with recombinant Bet v 7, and extract inhibition tests were performed with the same rBet v 7.

RESULTS

IgE to rBet v 7 was detected in 43 (17%) of 253 patients. It was associated with asthma (P < .028) and oral allergy syndrome (P < .017) in univariate but not multivariate analysis adjusted for IgE to profilins (Phl p 12), PR-10s (Bet v 1), and lipid transfer proteins (Pru p 3). IgE to rBet v 7 was also highly prevalent (47/74, 63%) among patients with unexplained sensitization to birch pollen extract. In patients with unexplained sensitization to ragweed, mugwort, pellitory, Plantago and plane tree pollen, the levels of IgE to those extracts correlated with the levels of IgE to rBet v 7, and they were also significantly inhibited by rBet v 7 (inhibition range 45%-74%).

CONCLUSIONS

IgE sensitization to cyclophilin is frequent in pollen-allergic patients living in temperate areas and can produce "false" positive outcomes in skin prick and IgE tests to pollen extracts. Molecular diagnostic guidelines should include this panallergen family.

Worldwide Heterogeneity of Food Allergy: Focus on Peach Allergy in Southern Italy

Food allergy (FA) has shown an increasing prevalence in the last decades, becoming a major public health problem. However, data on the prevalence of FA across the world are heterogeneous because they are influenced by several factors. Among IgE-mediated FA, an important role is played by FA related to plant-derived food which can result from the sensitization to a single protein (specific FA) or to homologous proteins present in different foods (cross-reactive FA) including non-specific lipid transfer proteins (nsLTPs), profilins, and pathogenesis-related class 10 (PR-10). In addition, the clinical presentation of FA is widely heterogeneous ranging from mild symptoms to severe reactions up to anaphylaxis, most frequently associated with nsLTP-related FA (LTP syndrome). Considering the potential life-threatening nature of nsLTP-related FA, the patient's geographical setting should always be taken into account; thereby, it is highly recommended to build a personalized approach for managing FA across the world in the precision medicine era. For this reason, in this review, we aim to provide an overview of the prevalence of nsLTP-mediated allergies in the Mediterranean area and to point out the potential reasons for the different geographical significance of LTP-driven allergies with a particular focus on the allergenic properties of food allergens and their cross reactivity.

Cross-Reactivity of Ragweed Pollen Calcium-Binding Proteins and IgE Sensitization in a Ragweed-Allergic Population from Western Romania

Ragweed pollen allergy is the most common seasonal allergy in western Romania. Prolonged exposure to ragweed pollen may induce sensitization to pan-allergens such as calcium-binding proteins (polcalcins) and progression to more severe symptoms. We aimed to detect IgE sensitization to recombinant Amb a 9 and Amb a 10 in a Romanian population, to assess their potential clinical relevance and cross-reactivity, as well as to investigate the relation with clinical symptoms. rAmb a 9 and rAmb a 10 produced in Escherichia coli were used to detect specific IgE in sera from 87 clinically characterized ragweed-allergic patients in ELISA, for basophil activation experiments and rabbit immunization. Rabbit rAmb a 9- and rAmb a 10-specific sera were used to detect possible cross-reactivity with rArt v 5 and reactivity towards ragweed and mugwort pollen extracts. The results showed an IgE reactivity of 25% to rAmb a 9 and 35% to rAmb a 10. rAmb a 10 induced basophil degranulation in three out of four patients tested. Moreover, polcalcin-negative patients reported significantly more skin symptoms, whereas polcalcin-positive patients tended to report more respiratory symptoms. Furthermore, both rabbit antisera showed low reactivity towards extracts and showed high reactivity to rArt v 5, suggesting strong cross-reactivity. Our study indicated that recombinant ragweed polcalcins might be considered for molecular diagnosis.

A randomized, double-blind, placebo-controlled trial with mannan-conjugated birch pollen allergoids

BACKGROUND

There is still great need to develop new strategies to improve the efficacy of allergen immunotherapies with optimal safety standards for patients. A new promising approach is to couple allergoids to mannan. The objective of this phase IIa/IIb study was to identify the optimal dose of mannan-conjugated birch pollen allergoids for the short-course treatment of birch pollen-induced allergic rhinoconjunctivitis.

METHODS

For this prospective, randomized, double-blind, placebo-controlled, dose-finding study, 246 birch pollen-allergic adults received 0.5 mL placebo or 1000, 3000 or 10,000 mTU/mL of mannan-conjugated birch pollen allergoids at five pre-seasonal visits. Efficacy was assessed by comparing allergic rhinoconjunctivitis symptoms and use of anti-allergic medication during the peak of the birch pollen season 2020. Immunologic, tolerability and safety effects were also analysed.

RESULTS

The highest dose of mannan-conjugated birch pollen allergoids reduced the combined symptom and medication score during the peak birch pollen season by a median of 24.7% compared to placebo. The production of Bet v 1 specific IgG4 significantly increased in a dose-dependent manner (3.6- and 4.5-fold) in the 3000 and 10,000 mTU/mL groups. The Bet v 1 specific IgE/IgG4 ratio was also strongly reduced (up to -70%). No fatalities nor serious adverse events were reported, and no adrenaline was used. In total, four systemic reactions occurred (two grade I and two grade II).

CONCLUSION

All doses of mannan-conjugated birch pollen allergoids can be considered as safe. Since the application of 10,000 mTU/mL resulted in the highest efficacy, this dose qualifies for further investigation.

Air pollutants contribute to epithelial barrier dysfunction and allergic diseases

Air pollution is a global problem associated with various health conditions, causing elevated rates of morbidity and mortality. Major sources of air pollutants include industrial emissions, traffic-related pollutants, and household biomass combustion, in addition to indoor pollutants from chemicals and tobacco. Various types of air pollutants originate from both human activities and natural sources. These include particulate matter, pollen, greenhouse gases, and other harmful gases. Air pollution is linked to allergic diseases, including atopic dermatitis, allergic rhinitis, allergic conjunctivitis, food allergy, and bronchial asthma. These pollutants lead to epithelial barrier dysfunction, dysbiosis, and immune dysregulation. In addition, climate change and global warming may contribute to the exacerbation and the development of allergic diseases related to air pollutants. Epigenetic changes associated with air pollutants have also been connected to the onset of allergic diseases. Furthermore, these changes can be passed down through subsequent generations, causing a higher prevalence of allergic diseases in offspring. Modulation of the aryl hydrocarbon receptor could be a valuable strategy for alleviating air pollutant-induced epidermal barrier dysfunction and atopic dermatitis. A more effective approach to preventing allergic diseases triggered by air pollutants is to reduce exposure to them. Implementing public policies aimed at safeguarding individuals from air pollutant exposure may prove to be the most efficient solution. A pressing need exists for global policy initiatives that prioritize efforts to reduce the production of air pollutants.

Aerobiological and clinical study in the semidesertic area of the Southeastern of Spain

Aerobiological studies constitute a relevant tool to predict the most influential parameters over the pollen seasons with significant clinical relevance in the allergic populations. The aim of this study was to describe the aerobiological behaviour of the most relevant allergenic sources in the semi-arid area of southeast of Spain (Almería) and to investigate the correlation with meteorological factors and clinical symptoms of allergic patients. Daily pollen count and meteorological parameters of Almería, Spain, were compiled for ten years. The clinical symptoms of 248 allergic patients were also recorded. Descriptive statistics and correlations between variables were assessed. Multivariate analyses were performed to predict the influence of meteorological factors on pollen concentration and the risk of suffer respiratory symptoms. Eight pollen families were identified as the most relevant allergenic sources. Temperature correlated with main pollen season evolution of all taxa whereas rainfall and relative humidity only correlated in Oleaceae, Pinaceae, Amaranthaceae, Asteraceae and Urticaceae. Rainfall and relative humidity were the most influential predictors of pollen concentration, except in Amaranthaceaea and Poaceae families, while temperature only influenced on Cupressaceae and Urticaceae pollen concentrations. A significant positive influence was observed between maximum temperature and rainfall with the appearance of allergic symptoms in patients sensitized to grasses, Parietaria sp. and Olea sp. This study, highlight the main aerobiological features in the region and establish a suitable tool for clinical follow-up and management of allergic patients. Further studies are needed to establish an accurate measurement aimed to control and prevent pollinosis in sensitized patients.

Assessment of environmental risk areas based on airborne pollen patterns as a response to land use and land cover distribution

Allergic respiratory diseases are considered to be among the most important public health concerns, and pollen is the main cause of allergic respiratory diseases worldwide. However, the biological component of air quality is largely underestimated, and there is an important gap in the legislation in this area. The aims of this study were to characterise the occurrence and incidence of pollen exposure in relation to potential pollen sources and to delineate the main areas of aerobiological risk in the Madrid Autonomous Region based on homogeneous patterns of pollen exposure. This study uses the historical aerobiological database of the Madrid Region Palynological Network (central Spain) from ten pollen stations from 1994 to 2022, and the land-use information from the Corine Land Cover. Multiple clustering approaches were followed to group the sampling stations and subsequently all the 1 × 1km pixels for the Madrid Autonomous Region. The clustering dendrogram for land-use distribution was compared to the dendrogram for historical airborne pollen data. The two dendrograms showed a good alignment with a very high correlation (0.95) and very low entanglement (0.15), which indicates a close correspondence between the distribution of the potential pollen sources and the airborne pollen dynamics. Based on this knowledge, the Madrid Autonomous Region was divided into six aerobiological risk areas following a clear anthropogenic gradient in terms of the potential pollen sources that determine pollen exposure in the Madrid Region. Spatial regionalisation is a common practice in environmental risk assessment to improve the application of management plans and optimise the air quality monitoring networks. The risk areas proposed by scientific criteria in the Madrid Autonomous Region can be adjusted to other operational criteria following a framework equivalent to other air quality networks.