Pollen Season Research Articles

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

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

Pollen season variations among anemophilous species in an Atlantic-influenced mediterranean environment: a long term study (1993-2022).

Numerous studies have shown that climate change is impacting the airborne pollen concentration of various anemophilous plant species, both herbaceous and woody. The aim of this study was to determine whether this trend, highly marked in Europe, is also occurring in the city of Huelva (south-western Spain), an area with a milder Mediterranean climate. The factors influencing the main pollen season were studied for all local taxa accounting for more than 1% of the total pollen collected, over the period 1993-2022, using a volumetric Hirst type trap to determine concentration. The study included a trend analysis of meteorological variables susceptible to climate change, specifically maximum, minimum and average temperature, precipitation and the number of hours of insolation per day. Although some of the variables analysed do not show significant trends for most taxa, such as start date or peak date, the overall results indicate a trend in the airborne pollen dynamics for herbaceous and woody taxa. Six of the eight woody taxa studied showed a significant trend towards increased pollen concentration, some of which are associated with temperature in previous seasons. In contrast, three of the five herbaceous taxa, which are more sensitive to short term meteorological variables, show a significant acceleration in the end date of the main pollen season, correlated negatively with temperature and insolation. In conclusion, some incipient changes are occurring, which may be indicative of future consequences on biodiversity in the Mediterranean area influenced by the Atlantic Ocean.

Flowering seasonality and airborne pollen recent trends in Sierra de las Nieves, the southernmost National Park in continental Spain

Sierra de las Nieves is the southernmost National Park in continental Spain and, in a global warming scenario, it is important to determine the impacts of climatic variations on the vegetation, with special relevance to their reproductive cycles. The flowering seasonality and intensity of the dominant anemophilous species usually reflect the response of the vegetation to climate variations, which can be monitored through the atmospheric pollen concentrations. In this study, airborne pollen was analysed for 6 years (2018–2023). A pollen calendar was elaborated to show the flowering seasonality and intensity of the dominant anemophilous taxa. Spring was the season with the highest airborne pollen diversity and intensity, Quercus being the pollen type with the highest concentrations. We observed that weather conditions influenced the presence of airborne pollen. Precipitation and relative humidity reduce pollen concentrations, while temperature rises increase them during the pre-peak period and reduce them during the post-peak. Wind dynamics play different roles depending on the pollen type considered given the heterogeneous distribution of the pollen emission sources. Significant advances were detected in the start date of the main pollen season of Quercus and Olea, as well as in the peak date of Quercus. On the contrary, other taxa such as Pinus or Poaceae did not show any trend. This brings to the fore that the responses to climatic variations may differ from one taxon to another, a continuous study in natural areas being required for detecting possible changes in the observed trends.

The SQ tree sublingual immunotherapy tablet is effective and well tolerated in children-A pivotal phase III trial.

Allergic rhinitis and/or conjunctivitis (AR/C) induced by tree pollen is common and negatively impacts quality of life in children and adolescents. This phase III trial investigated the efficacy and safety of the SQ tree SLIT-tablet in a paediatric population (5-17 years) with moderate-to-severe AR/C induced by pollen from birch and trees in the birch homologous group. Nine hundred and fifty-two subjects were randomized (1:1) to daily treatment with SQ tree SLIT-tablet or placebo for up to 52 weeks and had free access to AR/C symptom-relieving medications. The primary endpoint was the average total combined score (TCS); sum of average daily symptom score (DSS) and average daily medication score (DMS) during the birch pollen season (BPS). Key secondary endpoints included average DSS and DMS during BPS and average TCS, DSS and DMS during tree pollen season (TPS). SQ tree SLIT-tablet demonstrated a statistically significant and clinically relevant treatment effect compared with placebo for the TCS during BPS with an absolute treatment difference of 1.29 (95% CI: 0.58, 2.00; p = .0004) and a relative reduction of 21.9% (95% CI: 10.6, 31.9). Results were substantiated by reductions in both DSS and DMS versus placebo during the BPS and in DSS, DMS and TCS during the TPS. Treatment was generally well tolerated. Most treatment-related adverse events were mild or moderate local administration site reactions. This is the first paediatric trial to provide robust evidence of efficacy and safety of the SQ tree SLIT-tablet in tree pollen-induced AR/C in a paediatric population (5-17 years).

Impact of climate change on the pollen season on relevant species in Iberian’s dehesa: a case study of Fraxinus sp.

Impact of climate change on the pollen season on relevant species in Iberian’s dehesa: a case study of Fraxinus sp.

Sensitizations to pollen differ between Central European and Sub-Saharan African atopic dermatitis patients

Summary Background Atopic dermatitis (AD) is often associated with allergic comorbidities, such as allergic asthma or allergic rhinoconjunctivitis (ARC). Sensitizations to pollen can directly impact AD, as patients can experience exacerbation during pollen season. This study aims to gain more insights into the pollen sensitization patterns of AD patients in Central Europe compared with sub-Saharan Africa (SSA). Methods We performed a case–control study involving a total of 90 participants: 20 AD patients and 10 healthy controls (HC) each from Switzerland (CH), Tanzania (TZ), and Madagascar (MD). We collected clinical data and serum samples and performed a multiplex IgE test (ALEX2 Allergy Explorer, MacroArray Diagnostics, Vienna, Austria). Results The prevalence of ARC and asthma in AD patients was similar in all countries (ARC: 60% TZ, 70% CH, 75% MD; asthma: 25% TZ, 30% CH, 20% MD). Total IgE levels were significantly higher in both SSA HC populations compared with the Swiss HC. The analysis of specific IgE levels revealed major differences in sensitization patterns between Africa and Europe, especially regarding grass pollen allergens. Swiss AD patients were sensitized to various grass pollen such as Bahia grass, Bermuda grass, common reed, perennial ryegrass, rye, and timothy grass. However, these allergens were irrelevant in the SSA population: no AD patient or HC subject was sensitized to the tested grass pollen. Conclusion The considerably different sensitization patterns between European and SSA AD patients warrant the development of allergy testing and desensitization therapies tailored to the African setting. Therefore, there is a need to characterize local pollen types and counts.

Label-free quantitative phase imaging and analysis of airborne pollen

Abstract Pollen morphology, involving the physical characteristics of pollen grains from seed plants during reproduction, plays an important role in plant biology, ecology, and evolution. High pollen concentrations in the air can degrade air quality and exacerbate respiratory conditions such as asthma. Understanding pollen morphology and its implications for air quality is significant for mitigating respiratory health risks. Conventionally, fluorescence microscopy is used for pollen imaging, but photobleaching, quenching, and phototoxicity affect the surface morphology and do not provide quantitative data on the pollen grains. For this study, we used bright field (BF) imaging and quantitative phase imaging (QPI), a label-free interferometric microscopy method, to look at differences in the shape of pollen. BF imaging provides information about the shape and size of the different pollens but has a limitation of low contrast. To obtain high-contrast images and quantitative data on the pollen grains without any exogenous agents, we employed QPI and BF imaging in the present study. QPI enables the extraction of detailed information regarding the cell wall, aperture, and thickness of pollen while also maintaining their natural state without the need for chemical treatments. In the present work, we sampled the ambient air from May 2023 to January 2024 on the IIT Delhi campus. Subsequently, QPI and BF imaging have been done for pollen identification and phase analysis of arboreal and non-arboreal pollen. Further, by utilizing the information obtained from BF microscopy and QPI, different species of pollen have been identified, and a pollen calendar has been prepared for exhibiting pollen season throughout the year. To the best of the authors’ knowledge, they have conducted the QPI of airborne pollen grains for the first time; this technique holds great potential for characterizing airborne pollens without the need for staining or sample preparation.

Ecological and allergenic significance of atmospheric pollen spectra from a Grassland-Savanna ecotone in North West province, South Africa

Southern Africa’s floral, topographic and climatic diversity manifests in distinctive bioregions where aerobiology studies are needed to manage allergenic health problems, especially in urban areas. Previous studies underline different seasonal pollen fluctuations for the biomes, encouraging regional studies. These studies have been previously restricted to large cities such as Cape Town, Johannesburg and Pretoria whereas small cities such as Potchefstroom in the North-West province are understudied. The South African Pollen Monitoring Network (SAPNET) seeks to fill this lacuna, enhancing ecological and health-related knowledge, with regard to the allergenicity of the recorded pollen. Here, we investigate plant phenology and resulting pollen production within the Grassland and Savanna biomes around Potchefstroom, a fast-growing city in the North West province, comparing it with other SAPNET sites. As a SAPNET initiative, pollen monitoring in Potchefstroom involved monthly collections using a Lanzoni 7-day spore trap over 13 months from December 2022 to 2023. This facilitated the development of a preliminary pollen calendar and a pollen atlas, detailing pollen types’ morphology, ecology, pollination modes, and allergenicity. Initial findings revealed Potchefstroom’s pollen calendar, with tree pollen (60% of the Annual Pollen Index (API)) mainly from northern hemisphere species such as Cupressus (c. 11% of API) and Platanus (c. 18%), which released pollen in spring. Grass pollen was predominant from November to April (c. 18% of API). Potchefstroom recorded South Africa’s highest levels of Ambrosia pollen (c. 7% of API), a major allergen, in March and April. Noteworthy is the unusual abundance of pollen of the neophyte Ulmus (c. 14%) in December. This study highlights the pollen patterns of the Grassland and Savanna biomes around Potchefstroom. The region, with its mosaic of urban spaces, natural grass-/woodland, and agricultural land, exhibits distinct characteristics when contrasted with major, more densely populated cities such as Bloemfontein, Pretoria, and Johannesburg.

Comparative Analysis of Grass Pollen Dynamics in Urban and Rural Ireland: Identifying Key Sources and Optimizing Prediction Models

The Poaceae family, one of the most diverse and widespread angiosperms, is prevalent in various natural and urban environments and is a major cause of allergies, affecting over 20% of the population in Europe, specifically in Ireland. With extensive grasslands, Ireland supports numerous grass species, though pollen release varies due to the family’s complexity. The Hirst spore-trap is commonly used to sample airborne pollen, but the area of influence is debated and may differ by pollen type. This study compares grass pollen seasons between rural Carlow and urban Dublin, aiming to create forecast models for airborne pollen and identify key grass areas influencing the main pollen season (MPS). Two Hirst samplers were analyzed, using data up to 2020, and two threshold models (based on Swedish and Danish studies) were tested to find the best fit for Ireland. Airmass footprints were calculated using Hysplit and combined with grassland data to pinpoint major pollen sources. The results showed that Carlow had higher pollen concentrations but shorter seasons than Dublin. The Swedish threshold method was the most accurate for Ireland, with the Wicklow Mountains identified as a significant pollen source. These findings improve the understanding of pollen dynamics and support better public health and allergy management.

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.

Impact of rising CO2 and temperature on grass phenology, physiology, and pollen release patterns in northern latitudes

Climate change has complex effects on vegetation, including native grasses and those used as fodder plants. Like many other plant species, grasses respond to climate change by altering their phenology and physiological behavior, leading to changes e.g. in growth, reproduction and metabolic processes. Our study is the first to explore how Phleum pratense and Alopecurus pratensis respond to rising CO2 and temperatures projected for northern latitudes for two growing seasons. We investigated growth, phenology, pollen release, and physiological parameters in plants cultivated under these conditions, simulated within environmentally controlled chambers.Treatment with elevated temperature reduced the number of generative tillers and, consequently, decreased both the number of inflorescences and the season pollen integrals. Pollen release from P. pratense started up to 17 days earlier, and the daily peak concentration of released pollen was observed 1–2 h earlier in chambers with elevated temperatures when compared to the present climate conditions. Similar effects were noted in A. pratensis. Elevated CO2 (EC) increased net photosynthesis of P. pratense, but this effect was reduced under elevated temperature (ET), suggesting an antagonistic interaction. In A. pratensis, both elevated CO2 and temperature had an additive effect on increasing net photosynthesis, with the highest rate observed under the combined ETEC treatment. The elevated temperature or CO2 did not affect the plant biomass.Our findings propose that the rising temperatures in northern latitudes decrease the flowering of studied grasses and shift the seasonal and daily start of the pollen release. Changes in tiller proportions, reduced pollen integrals, and fewer inflorescences suggest that a warmer climate may negatively impact reproductive success, ecological fitness, and allergenic burden of these grasses.

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.

Low CD46 expression on activated CD4+ T cells predict improved Th1 cell reactivity to calcitriol in majority of patients with allergic eosinophilic asthma and healthy donors.

Previous research showed that the intracellular complement system, with CD46 as its central molecule, regulates the Th1 response associated with IFN-γ production and transition to a type 1 regulatory response (Tr1) characterized by IL-10 production. This transition can be influenced by a vitamin D (calcitriol), favouring a shift towards Tr1 cells and increased IL-10 production, as described in some autoimmune diseases. It is unknown whether calcitriol modulates CD46-induced Th1 response towards regulatory type 1 T cells (Tr1) in allergic eosinophilic asthma and its value in relation to reducing inflammatory response. CD4+ T cells from 58 patients with allergic eosinophilic asthma (AEA) and 49 healthy donors (HDs) were stimulated with αCD3/αCD46/IL-2 or αCD3/αCD46/IL-2/Calcitriol in vitro for 60 h and analyzed by flow cytometry. IFN-γ and IL-10 levels in cell culture supernatants were measured using ELISA. CD4+ T cells from patients with AEA demonstrated elevated CD46 expression in both the non-activated state and under stimulation conditions with αCD3/αCD46/IL-2 or αCD3/αCD46/IL-2/Calcitriol. Moreover, CD46 expression in AEA patients fluctuated with the pollen season, showing a significant increase during period of low pollen exposure. Calcitriol further induced CD4+Tr1 cells from in vitro generated CD4+Th1 cells in both HDs and AEA patients. However, in both cohorts were individuals (HDs: 35/49, AEA: 40/58) who responded to calcitriol with a more pronounced regulatory response. The calcitriol-induced regulatory effect manifested by a stronger surface decrease of CD46 on activated CD4+ T cells (by 40% in HDs and by 26% in AEA), accompanied by a significant inhibition of IFN-γ and increased IL-10 production (by 31% in HDs and by 85% in AEA). These individuals were termed as the CD46D group. Contrary to this, calcitriol induced an increase in CD46 expression at the CD4+ T cell surface in a minor group of HDs (14/49), and AEA patients (18/58), who were termed as the CD46I group. In CD46I group, CD4+ T cells produced less IFN-γ in comparison with CD46D group (by 33% in HDs and by 43% in AEA) and were unable to upregulate IL-10 production following stimulation with αCD3/αCD46/IL-2/Calcitriol. Our results suggest the potential existence of a key for stratifying individuals suitable for calcitriol treatment in the context of low serum vitamin D levels. After validation in clinical studies, this key could be used as an adjunctive therapy not only for patients with allergic eosinophilic asthma, but also for other diseases.

A second Artemisia pollen peak in autumn in Vienna: reaching the point of no return?

AbstractThe Artemisia (mugwort) pollen season usually ranges from July until September, with one peak period around mid-August in Vienna (Austria). During the last decade, Artemisia pollen was also recorded later in September. This pattern was concluded by a significant peak pollen concentration day in autumn of 2023, which exceeded the usual summer peak pollen concentration day. The Artemisia pollen data from Vienna for the last ten years (2014–2023) were therefore analysed for a temporal trend. In addition, weather data from Vienna (temperature, precipitation, and relative humidity and sun hours) were retrieved and analysed to find a possible association with Artemisia pollen indices. No significant trend could be observed regarding the Artemisia pollen season parameters and no correlation was found between the weather data and the Artemisia pollen integrals during summertime. However, a significant positive correlation was found between higher temperatures during autumn and the occurrence of Artemisia pollen during this time. This suggests that a significant change in the Artemisia pollen season can be expected during years with a mild, summer-like autumn. Until now, it is not clear which species of Artemisia cause the pollination in autumn. A. annua and A. verlotiorum are two major suspects that could have established themselves in Vienna, but further evidence is needed. Considering the impact of global climate change, the shift in the pollen season for Artemisia described in this study could represent a point of no return.

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.

Temporal trends of seasonal pollen indexes in a region of Northern Italy (2001–2022)

Increasing trends in allergic respiratory diseases may be linked to climate changes affecting pollen levels. This study aimed to investigate the temporal trends in seasonal indexes of 9 allergenic pollen types in the Veneto Region, Northern Italy. Available daily data from 20 monitoring stations covered 2001–2022 for Corylaceae, Cupressaceae, Poaceae, Oleaceae, and Urticaceae (pollen families), and 2006–2022 for Alnus, Betula, Ambrosia, and Artemisia (pollen genera). The 95-percentage method was used to identify the start/end dates of pollen seasons annually, and the seasonal cumulative pollen concentration (Seasonal Pollen Integral, SPIn) was calculated. The non-parametric Theil-Sen median slope method was used to examine trends in pollen seasons’ start day, duration, and SPIn in the whole region and for climatic areas (alpine, subcontinental eastern, subcontinental western). The results showed a clear upward trend in SPIn for several pollens, with median slopes ranging from 326 (Alnus) to 1089 p/m3 per 10yrs (Corylaceae); exceptions were Artemisia, whose SPIn decreased over time (−26 p/m3 per 10yrs), and Ambrosia, Betula, and Urticaceae, which did not show a clear trend. For families, pollen seasons showed a trend for anticipation (from −4.7, Urticaceae, to −13.5 days/10yrs, Oleaceae) and extended duration (from 8.3, Cupressaceae, to 13.3 days/10yrs, Oleaceae). An evident heterogeneity across the climatic areas was seen for the SPIn, with the subcontinental western area exhibiting the highest loads and most prominent increases over time. In conclusion, increased levels and prolonged seasons for several pollen taxa observed in the Veneto Region, particularly in subcontinental areas, suggest increasing risks for individuals with pollen allergies. Addressing this issue requires measures of mitigation and adaptation to climate-driven changes in pollen exposure.

From trees to rain: enhancement of cloud glaciation and precipitation by pollen

Abstract The ability of pollen to enable the glaciation of supercooled liquid water has been demonstrated in laboratory studies; however, the potential large-scale effect of plants and pollen on clouds, precipitation and climate is pressing knowledge to better understand and project clouds in the current and future climate. Combining ground-based measurements of pollen concentrations and satellite observations of cloud properties within the United States, we show that enhanced pollen concentrations during springtime lead to an increase in cloud ice fraction of up to 0.1 in the temperature regime where pollen are considered to act as INP (−15 ∘ C and −25 ∘ C ). We further establish the link from the pollen-induced increase in cloud ice to a higher precipitation frequency. In light of anthropogenic climate change, the extended and strengthened pollen season and future alterations in biodiversity can introduce a localized climate forcing and a modification of the precipitation frequency and intensity.

Aerobiology of Olive Pollen (Olea europaea L.) in the Atmosphere of the Iberian Peninsula

Olea europaea L. pollen is one of the main causes of pollinosis and respiratory diseases in the Iberian Peninsula (IP). The aim of this study was to provide a pollen calendar in different regions of the IP, which could help allergists and allergic patients in the management of Olea europaea allergic diseases, and to update/complement what has already been reported on olive trees’ aeropalynology in this region. Airborne Olea pollen dynamics were analyzed over a period of 8 years in a total of 21 localities, 7 in Portugal and 14 in Spain. Airborne pollen monitoring was carried out using the Hirst-type spore trap method and following the recommendations of the Quality Control Working Group of the European Aerobiology Society. The daily pollen count, the annual pollen profile, the Annual Pollen Integral (APIn), the Seasonal Pollen Integral (SPIn) and the Pollen Peak, all expressed in number of pollen grains per cubic metre of air, together with the main pollen season and its characteristics, the Start Day, the End Day and the length of the pollen season, were calculated for each sampling station. Differences in mean Olea pollen concentration between odd and even years were also analyzed. On average, the main pollen season (MPS) started in April/May and ended in June, with Pollen Peaks recorded in May, except in Burgos, where it was recorded in June. The longest MPS occurred in Lisbon, Oviedo and Valencia (53 days) and the shortest in Vitoria (25 days). A high daily pollen concentration (i.e., &gt;200 grains/m3) was recorded between 1 and 38 days along the year in all sampling stations of the southwest quadrant of the IP and in Jaén. A biannual pattern, characterized by alternating years of high and low pollen production, was found in the southwest of the IP. In conclusion, the study provided a deeper understanding of the pollination behaviour of olive trees in the IP and allowed the establishment of a representative Olea pollen calendar for this region. In addition, our results suggest the usefulness of investigating more detailed relationships between annual Olea pollen, allergen sensitization and symptoms, both for allergists involved in the study and management of allergic respiratory diseases caused by this species and for the self-management of disease in allergic subjects.

Real-World Study of Ragweed Sublingual Immunotherapy in Hungary.

Ragweed (Ambrosia elatior) has become invasive in Europe, causing significant respiratory issues. Subcutaneous allergen immunotherapy (SCIT) has long been used to manage pollen allergies, but sublingual immunotherapy (SLIT) has gained interest. This study aimed to evaluate the clinical benefits of ragweed SLIT under real-world in a cohort of Hungarian patients allergic to ragweed pollen. We retrospectively reviewed the clinical records of 57 patients during the 2015 and 2016 ragweed pollen seasons. Patients were divided into two groups: Group 1 (n = 29), who had not received immunotherapy, and Group 2 (n = 28), who had previously undergone immunotherapy with another sublingual preparation. All patients were treated with Oraltek® ragweed for 4-6 months, initiating 2-4 months before the pollen season and rest of the period was 2 months of the 2016 pollen season. Symptom score (SS), medication score (MS), and combined symptom and medication score (CSMS) were evaluated intra- and intergroup. Pollen counts were consistent between 2015 and 2016. All patients showed significant improvement in SS, MS, and CSMS, with a large effect size (>0.8). Group 2 had significantly lower SS and CSMS in 2015 because of prior immunotherapy. By 2016, both groups exhibited marked improvements, with Group 1 showing a 75% improvement in CSMS. No local or systemic reactions were recorded, indicating a high safety profile. Ragweed SLIT significantly improved symptoms and reduced use of medication in patients allergic to ragweed pollen. The treatment was effective even in patients with previous immunotherapy, with a high benefit-risk ratio demonstrated by the absence of adverse reactions. These findings support the use of Oraltek SLIT for managing ragweed pollen allergy.

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.