Pollen Counts Research Articles

Variation in airborne pollen concentrations among five monitoring locations in a desert urban environment

The urbanization of the Las Vegas Valley has transformed this part of the Mohave Desert into a green oasis by introducing many non-native plant species, some of which are allergenic. Typically, one monitoring station is established per city to obtain pollen counts for an entire metropolitan area. However, variations in pollen concentrations could occur among different microenvironments. The objective of this study is to measure and compare pollen concentrations in five locations in Las Vegas to determine if there are significant differences between microenvironments within the city. Air samples were collected from five sites across the Las Vegas Valley over a 1-year period. Prepared slides were analyzed with a light microscope for pollen grains and converted into airborne pollen concentrations. Mixed model methods were used to determine mean differences. Tree pollen was the greatest contributor to the annual average airborne pollen concentrations (130 grains/m3) compared to weeds (6 grains/m3) and grass (3 grains/m3). The highest peak occurred in March 2016 (9589 total grains/m3). There were several differences among sites with respect to concentrations of individual tree species and for total weed and grass concentrations. We observed significant variations in concentration and composition among the five pollen collection stations that were established across the Las Vegas Valley. This study presented new outdoor pollen data for the southwest region of the USA, focused in Las Vegas. The results indicate that more sites and comprehensive monitoring of outdoor allergens are needed to provide accurate information to the community about outdoor air quality conditions.

Sheathed Panicle Phenotype (cv. Sathi) Maintains Normal Spikelet Fertility and Grain Filling under Prolonged Heat Stress in Rice

The failure of panicle exertion or sheathed panicle (SP) phenotype in rice (Oryza sativa L.) has been associated with spikelet sterility and grain yield loss under both stress and nonstress conditions. A unique SP phenotype (cv. Sathi) having the potential to maintain normal seed‐set and grain weight (exposed to 38°C for 20 d) was identified. Despite the higher spikelet tissue temperatures (38–40°C) at anthesis, pollen count and germinated pollen grains on the stigma were greater in number than the threshold required for successful seed‐set. Panicle length, total spikelet number, and grain thickness in SP phenotype were not affected significantly by heat stress. In addition, lower lipid peroxidation in spikelets and nonsignificant reduction in carbohydrate metabolism enzymes (invertases and starch synthase) were recorded during grain filling, even after 10 d of heat stress exposure. Minimal impact on carbohydrate metabolism enzymes would support normal sucrose unloading and starch synthesis in the grain and normal grain size under prolonged heat stress exposure. Our findings open novel avenues for genetic and molecular dissection for inducing greater heat stress resilience during anthesis and grain filling in sensitive, popular rice cultivars to sustain global food security under future uncertain environmental conditions.

New European Academy of Allergy and Clinical Immunology definition on pollen season mirrors symptom load for grass and birch pollen-induced allergic rhinitis.

The use of allergen immunotherapy (AIT) for allergic rhinitis and its clinical efficacy in clinical trials depends on the effective determination of pollen allergen exposure time periods. We evaluate pollen data from Germany to examine the new definitions on pollen season and peak pollen period start and end as proposed by the European Academy of Allergy and Clinical Immunology (EAACI) in a recently published Position Paper. The aim was to demonstrate the ability of these definitions to mirror symptom loads for grass and birch pollen-induced allergic rhinitis based on real-life data. Data coming from four pollen monitoring stations in the Berlin and Brandenburg area in Germany and for 3years (2014-2016) were used to investigate the correlation of season definitions, birch and grass pollen counts and total nasal symptom and mediation scores as reported by patients in "Patients Hay fever Diaries" (PHDs). After the identification of pollen periods on the basis of the EACCI criteria, a statistical analysis was employed, followed by a detailed graphical investigation. The analysis revealed that the definitions of pollen season as well as peak pollen period start and end as proposed by the EAACI are correlated to symptom loads for grass and birch pollen-induced allergic rhinitis reported by patients in PHDs. Based on our analysis, the validity of the EAACI definitions on pollen season is confirmed. Their use is recommended in future clinical trials on AIT as well as in daily routine for optimal patient care.

Pollen diversity in the atmosphere of Havana, Cuba

With a view to obtaining fuller information on airborne pollen content in the city of Havana, pollen sampling was carried out using a volumetric capture method, for the first time in Cuba. The study was conducted during 2 years (2011 and 2015). An annual pollen integral of 3414 grains was registered during the first year of study, whereas 5120 grains were observed along the 2015. Monthly maximum concentrations were recorded during April, June and July with total values close to 800 pollen grains. Of the 45 pollen types identified, Cecropia (38% of the total pollen identified in both years), Poaceae (18%), Urera type (9%) and Casuarina (6%) were particularly abundant. Although the main pollen types differed in terms of intradiurnal distribution, the highest concentrations were in all cases recorded between 0900 and 1300 hours. Maximum temperature was the variable most influencing airborne pollen counts in the air, with the exception of Casuarina. This paper sought to establish a methodological basis for the further development of aerobiological research in Cuba, thus helping to enhance the prevention and diagnosis of pollen allergies in the affected island population.

Short-term effect of outdoor mould spore exposure on prescribed allergy medication sales in Central France.

Outdoor moulds are classically associated with exacerbations of asthma. The aim of this paper was to examine nasal allergy morbidity by studying the short-term relationship between mould spore exposure and daily sales of reimbursable anti-allergic treatment in central France. The relationship between daily changes in mould concentrations and daily sales obtained from the national healthcare database was analysed with generalized additive models, taking into account confounding factors such as air pollution, weather conditions, pollen counts, and days of the week. During the study, the average total yearly number of treated people was around 10000 over approximately 230000 surveyed. The relative risk (95% CI confidence interval) of sales of oral antihistamines with topical treatment associated with an interquartile increase in mould concentration was significant for Cladosporium 1.079 [1.019-1.142] and Aspergillus-Penicillium (Asp-Pen) 1.051 [1.021-1.082] in the whole population. When the influence of age and sex was considered, the relationship was significant only in male children aged 0-12years and those aged between 13 and 49years for Cladosporium: 1.256 [1.081-1.460] and 1.151 [1.063-1.245], respectively. The relationship was also significant for Asp-Pen: 1.038 [1.003-1.075] for those aged between 13 and 49years and 1.056 [1.007-1.108] for adults over 50years of age. The association between prescribed daily sales of oral antihistamines with topical treatment sales is associated with temporal changes to Cladosporium and Aspergillus-Penicillium in the whole population. When the influence of age and sex was considered, these two moulds contributed to prescribed medication sales only in the male general population.

Allergy onset and local investor distraction

Abstract We posit that investor distraction can be exogenously triggered by allergy onset's degrading effects on local investors’ health and cognitive functioning. We document that allergy onset is related to lower trading activity. We use daily pollen counts to measure the severity of allergy onset at different locations and show that stocks of firms located in areas with severe allergy problems exhibit declines in trading volume and lower stock returns. Moreover, allergy onset is associated with both a decline in investor demand for firm information, as proxied by Google search volume, and stock underreaction to earnings news. Collectively our evidence supports the notion that the association of allergy onset and stock market outcomes may be emerging through a local investor distraction channel.

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

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

The analysis of the Corylus, Alnus and Betula pollen seasons in Toruń in 2014 and 2016

The paper presents the results of the research on the pollen seasons of hazel ( Corylus ), alder ( Alnus ) and birch ( Betula ) in 2014 and 2016. The samples were collected gravimetrically at weekly intervals. The deposition values were converted into the pollen grains concentration in 1 m 3 of air. The analysis of the pollen seasons was conducted based on the properties of the seasons: beginning, end, season duration, annual totals of pollen and maximum concentrations. The courses of the both compared pollen seasons differed. In 2014, the tree pollen season began two weeks later than in 2016, a year that was marked by high annual totals of pollen counts and maximum pollen concentrations of alder and birch. Only hazel showed higher values in 2014.

Serwisy z ogólnopolskimi informacjami o stężeniu pyłku roślin w Polsce w 2018 roku

Allergic rhinitis (AR) is the most common disease in allergy specialist’s practice and one of the most common in family doctor practice. The guidelines for allergic rhinitis management, allowing its good control, have been developed by the ARIA initiative. Nevertheless, we do not achieve satisfactory results in some patients. The effectiveness of AR treatment can be improved by using the application that allows to follow the symptoms of AR and informing about the expected pollen counts of sensitizing plants. The authors reviewed a list of nationwide websites and applications informing about the forecasted pollen counts in 2018.

Alder pollen season in Poland in 2018

Alder pollen grains constitute the important allergen sources in this respect in the Northern Hemisphere. The aim of the study was to investigate the concentration of alder (Alnus spp.) in Bialystok, Bydgoszcz, Cracow, Drawsko Pomorskie, Lublin, Olsztyn, Opole, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, Wroclaw and Zielona Gora in 2018. Measurements were performed by the volumetric method (Burkard and Lanzoni pollen samplers). Seasonal Pollen Index (SPI) was estimated as the annual sum of daily average pollen concentrations. The pollen season of alder in all Polish stations began on the 11th and 13th March and the high concentration persisted until the first days of April. The highest, record airborne concentration of 1068 pollen grains/m3 was noted in Lublin on the 13th March. The peak values of seasonal pollen count occurred between of 11th March and 4th April in all cities. In 2018 pollen concentration of alder was one of the lowest in all analysed cities.

The linkages with fires, vegetation composition and human activity in response to climate changes in the Chinese Loess Plateau during the Holocene

Holocene paleo-records of the Chinese Loess Plateau loess–soil profiles were used to reconstruct wildfire patterns and landscape evolution. We examine black carbon and charcoal influx, combined with the Magnetic susceptibility, δ13C values of soil organic matter, pollen counts and other paleo-environmental proxies to discuss interactions with biomass–climate during the Holocene. The history of fires from the charcoal and black carbon (BC, char and soot) influx at the two sites demonstrates a transition from climate-controlled low amplitude variations with peaks during the Early and Middle Holocene (11-3.1kyearsB.P.) to higher amplitude variability in fire occurrence decoupled from climate and tied to human activities during the Late Holocene (3.1-0kyearsB.P.). The difference in fire patterns was attributed to regional effective moisture and human land use over the entre Loess Plateau; meanwhile, fire activities observed during the Holocene are consistent with variations in vegetation composition inferred from δ13C values in soil organic matter, pollen counts, and paleoclimate proxies. Regional wildfires rarely occurred on the desert steppe dominated by a weedy C3 taxon (Artemisia, Compositae, and Chenopodiaceae dominated)during the late glacial period. A limited biomass would not meet fire propagation in the extreme colder and drier environment of the Loess Plateau during those periods, though. As the climate became ameliorated during the early Holocene, there was an increasing biomass and a sufficient contribution do to high fuel accumulation from C4 taxon (Gramineae). As the middle Holocene progressed toward warmer and wetter conditions, fire events were less frequent on the steppe and forest-steppe (e.g. expansion of trees C3,Quercus, Corylus) of the Loess Plateau. Subsequently, the number of local and regional fire events have largely increased with the colder and drier climate conditions (e.g. expansion of C3 weedy), which have been decoupling with intensive anthropogenic burning for farming since the past 3kyr.These data suggests that the regional fire patterns vary strongly along environmental gradients in the effective moisture and regional fuel availability as well as the spatial and temporal distributions of Neolithic burning practices over the Loess Plateau in response to the weakening East Asian monsoon during the Holocene.

Statistical techniques for modeling of Corylus, Alnus, and Betula pollen concentration in the air

Prediction of allergic pollen concentration is one of the most important goals of aerobiology. Past studies have used a broad range of modeling techniques; however, the results cannot be directly compared owing to the use of different datasets, validation methods, and evaluation metrics. The main aim of this study was to compare nine statistical modeling techniques using the same dataset. An additional goal was to assess the importance of predictors for the best model. Aerobiological data for Corylus, Alnus, and Betula pollen counts were obtained from nine cities in Poland and covered between five and 16 years of measurements. Meteorological data from the AGRI4CAST project were used as a predictor variables. The results of 243 final models (3 taxa $$\times$$ 9 cities $$\times$$ 9 techniques) were validated using a repeated k-fold cross-validation and compared using relative and absolute performance statistics. Afterward, the variable importance of predictors in the best models was calculated and compared. Simple models performed poorly. On the other hand, regression trees and rule-based models proved to be the most accurate for all of the taxa. Cumulative growing degree days proved to be the single most important predictor variable in the random forest models of Corylus, Alnus, and Betula. Finally, the study suggested potential improvements in aerobiological modeling, such as the application of robust cross-validation techniques and the use of gridded variables.

Seasonal asthma in Melbourne, Australia, and some observations on the occurrence of thunderstorm asthma and its predictability

We examine the seasonality of asthma-related hospital admissions in Melbourne, Australia, in particular the contribution and predictability of episodic thunderstorm asthma. Using a time-series ecological approach based on asthma admissions to Melbourne metropolitan hospitals, we identified seasonal peaks in asthma admissions that were centred in late February, June and mid-November. These peaks were most likely due to the return to school, winter viral infections and seasonal allergies, respectively. We performed non-linear statistical regression to predict daily admission rates as functions of the seasonal cycle, weather conditions, reported thunderstorms, pollen counts and air quality. Important predictor variables were the seasonal cycle and mean relative humidity in the preceding two weeks, with higher humidity associated with higher asthma admissions. Although various attempts were made to model asthma admissions, none of the models explained substantially more variation above that associated with the annual cycle. We also identified a list of high asthma admissions days (HAADs). Most HAADs fell in the late-February return-to-school peak and the November allergy peak, with the latter containing the greatest number of daily admissions. Many HAADs in the spring allergy peak may represent episodes of thunderstorm asthma, as they were associated with rainfall, thunderstorms, high ambient grass pollen levels and high humidity, a finding that suggests thunderstorm asthma is a recurrent phenomenon in Melbourne that occurs roughly once per five years. The rarity of thunderstorm asthma events makes prediction challenging, underscoring the importance of maintaining high standards of asthma management, both for patients and health professionals, especially during late spring and early summer.

ROPES Reveals Past Land Cover and PPEs From Single Pollen Records

Quantitative reconstructions of past vegetation cover commonly require pollen productivity estimates (PPEs). PPEs are calibrated in extensive and rather cumbersome surface-sample studies, and are so far only available for selected regions. Moreover, it may be questioned whether present-day pollen-landcover relationships are valid for palaeo-situations. We here introduce the ROPES approach that simultaneously derives PPEs and mean plant abundances from single pollen records. ROPES requires pollen counts and pollen accumulation rates (PARs, grains cm-2 year-1). Pollen counts are used to reconstruct plant abundances following the REVEALS approach. The principle of ROPES is that changes in plant abundance are linearly represented in observed PAR values. For example, if the PAR of pine doubles, so should the REVEALS reconstructed abundance of pine. Consequently, if a REVEALS reconstruction is ‘correct’ (i.e. ‘correct’ PPEs are used) the ratio ‘PAR over REVEALS’ is constant for each taxon along all samples of a record. With incorrect PPEs, the ratio will instead vary. ROPES starts from random (likely incorrect) PPEs, but then adjusts them using an optimization algorithm with the aim to minimize variation in the ‘PAR over REVEALS’ ratio across the record. ROPES thus simultaneously calculates mean plant abundances and PPEs. We illustrate the approach with test applications on nine synthetic pollen records. The results show that good performance of ROPES requires data sets with high underlying variation, many samples and low noise in the PAR data. ROPES can deliver first landcover reconstructions in regions for which PPEs are not yet available. The PPEs provided by ROPES may then allow for further REVEALS-based reconstructions. Similarly, ROPES can provide insight in pollen productivity during distinct periods of the past such as the Lateglacial. We see a potential to study spatial and temporal variation in pollen productivity for example in relation to site parameters, climate and land use. It may even be possible to detect expansion of non-pollen producing areas in a landscape. Overall, ROPES will help produce more accurate landcover reconstructions and expand reconstructions into new study regions and non-analogue situations of the past. ROPES will be available within the R package DISQOVER.

Nested cell strainers: An alternative method of preparing palynomorphs and charcoal

Centrifugation and sieving are essential techniques used in standard preparations of pollen and other palynological material. However, multiple centrifugation steps can potentially damage delicate palynomorphs and other microfossils, and the process of decanting after centrifugation can lead to loss of material. Traditional sieves often have a large surface area which makes manipulating smaller samples difficult and creates the need for potentially damaging techniques (e.g., sonication) to facilitate material through the sieve. We propose using stackable cell strainers as an alternative method for the preparation of pollen and charcoal samples. These sieves fit firmly on standard plastic 50ml centrifuge tubes and special rings allow the attachment of disposable syringes for suction. We demonstrate that the results of using cell sieves are comparable or better than those of traditional methods. Pollen counts from nine Holocene sites using the cell strainers showed similar concentrations of major palynomorphs in comparison to counts of samples processed following traditional methods. Visual comparison and counts of delicate pollen morphotypes, such as Pinaceae and Poaceae grains, indicated that fewer grains were damaged when cell strainers were used. Macrocharcoal preparations using cell strainers showed consistently lower counts than samples prepared using traditional methods, which may reflect lower rates of fragmentation of fossil charcoal during preparation. Finally, we demonstrate that nested cell strainers are also effective in processing lithified material and isolating and staining pollen from herbarium samples.

Seasonal changes in plant pollen concentrations over recent years in Vinnytsya, Central Ukraine

&lt;p&gt;The control of plant pollen season patterns is especially important in the expectation of climate change, as the timing of potential varying pollen seasons affects the human population. An ever-increasing number of people suffer from hay fever symptoms with varying severity during the pollen season. This paper presents data on the seasonal variations of pollen concentration and the factors which are the likely causes of these variations in Vinnytsya, a city in Central Ukraine, in order to establish the apparent pattern of this variation and so improve the efficiency of hay fever control in Ukraine.&lt;/p&gt;&lt;p&gt;Pollen counts were obtained by gravimetric and volumetric methods employing a Hirst-type volumetric spore trap.&lt;/p&gt;&lt;p&gt;Alder (&lt;em&gt;Alnus&lt;/em&gt;) and birch (&lt;em&gt;Betula&lt;/em&gt;) peaks of pollen release occurred approximately 1 month earlier than was observed at the end of the twentieth century. This was due to the seasonal heat accumulation related to the appropriate temperature regimen registered in January and February prior to the growing season. Other trees – including poplar (&lt;em&gt;Populus&lt;/em&gt;), maple (&lt;em&gt;Acer&lt;/em&gt;), walnut (&lt;em&gt;Juglans&lt;/em&gt;), common hazel (&lt;em&gt;Corylus&lt;/em&gt;) – did not show distinct changes in pollen season pattern over the past decades.&lt;/p&gt;&lt;p&gt;Mean daily temperature seems to be the leading factor promoting early season onset and a seasonal pollen peak shift of the grass and herb flora such as ragweed (&lt;em&gt;Ambrosia&lt;/em&gt;). The shift of the ragweed seasonal pollen maximum towards later in the season correlated with higher temperatures during September. Our study has shown that droughts may also significantly decrease the ragweed pollen concentration.&lt;/p&gt;

Prevalence of pollen-induced allergic rhinitis with high pollen exposure in grasslands of northern China.

BackgroundThe aim of this study was to investigate the prevalence of epidemiologic and physician‐diagnosed pollen‐induced AR (PiAR) in the grasslands of northern China and to study the impact of the intensity and time of pollen exposure on PiAR prevalence.MethodsA multistage, clustered and proportionately stratified random sampling with a field interviewer‐administered survey study was performed together with skin prick tests (SPT) and measurements of the daily pollen count.ResultsA total of 6043 subjects completed the study, with a proportion of 32.4% epidemiologic AR and 18.5% PiAR. The prevalence was higher in males than females (19.6% vs 17.4%, P = .024), but no difference between the two major residential and ethnic groups (Han and Mongolian) was observed. Subjects from urban areas showed higher prevalence of PiAR than rural areas (23.1% vs 14.0%, P < .001). Most PiAR patients were sensitized to two or more pollens (79.4%) with artemisia, chenopodium, and humulus scandens being the most common pollen types, which were similarly found as the top three sensitizing pollen allergens by SPT. There were significant regional differences in the prevalence of epidemiologic AR (from 18.6% to 52.9%) and PiAR (from 10.5% to 31.4%) among the six areas investigated. PiAR symptoms were positively associated with pollen counts, temperature, and precipitation (P < .05), but negatively with wind speed and pressure P < .05).ConclusionPollen‐induced AR (PiAR) prevalence in the investigated region is extremely high due to high seasonal pollen exposure, which was influenced by local environmental and climate conditions.

Hourly pattern of allergenic alder and birch pollen concentrations in the air: Spatial differentiation and the effect of meteorological conditions

In temperate climate widespread alder and birch are an important source of strong aeroallergens. The diurnal pattern of airborne pollen concentrations depends on the rhythm of pollen release from anthers as well as weather conditions, convection air currents, long-distance transport, pollen trap location and local vegetation. The aim of the study was to present a diurnal pattern of Alnus (alder) and Betula (birch) pollen concentrations in the air in a horizontal and vertical gradient and examine the weather parameters that had the greatest impact on the pattern. The study was conducted in Rzeszów City, southeast Poland over three years. Pollen grains were collected using a Hirst volumetric spore trap at three sampling points: two at 12 m the agl, and one at 1.5 m agl. Data were analysed using circular statistics and a nonlinear function. For alder, three models of hourly patterns were elaborated and the most common presented early morning minimum and early afternoon maximum. For birch, the most common model has one peak at night and a marked decrease in concentrations in early morning, although a second model has peak during early afternoon. A model with 3 peaks is much less common. These models are characteristic for warm temperate climate regions, where alders and birches are common. The diurnal patterns did not depend on the localization of traps or proximity of the pollen source, although these factors influenced the hourly concentrations, with higher values observed at roof level. Significant relationships between the hourly pollen counts and meteorological parameters were observed only for alder. Three incidents of increasing birch pollen concentrations were observed during the first two hours of precipitation and linked to a convection effect. Unstable weather conditions caused by air convection might strongly modify the circadian pattern and cause the nightly peaks concentrations. The general results are that people suffering from allergies may be exposed to high birch and alder pollen concentrations at almost all times during the day with the exception of the morning hours, as well as during the first hours of convective precipitation. Precise information on pollen concentrations aids in allergy prevention, so cities should provide aerobiological monitoring at least at “roof level” and “nose level”.

Immunotherapy With the SQ Tree SLIT-tablet in Adults and Adolescents With Allergic Rhinoconjunctivitis

PurposeThe SQ tree sublingual immunotherapy (SLIT)-tablet containing allergen extracts with the major allergen Bet v 1 from birch pollen is currently being developed for the treatment of tree pollen–induced allergic rhinitis/conjunctivitis with or without asthma. The aim of this Phase II trial was to investigate the dose-related efficacy and safety of the SQ tree SLIT-tablet. MethodsThis study was a randomized, parallel-group, double-blind, placebo-controlled, multi-national trial conducted in Europe. A total of 637 participants were randomized equally to receive placebo or treatment with the SQ tree SLIT-tablet in doses of 0.5, 1, 2, 4, 7, or 12 development units (DU). Treatment was initiated ~16 weeks before onset of the 2013 birch pollen season (BPS) and was continued throughout the BPS with a total duration of at least 6 months. During the BPS and tree pollen season (TPS), subjects assessed rhinoconjunctivitis symptoms and medication use on a daily basis in an electronic diary; weekly assessments of rhinoconjunctivitis quality of life were also made. FindingsAnalysis of the average daily symptom score during the BPS and the TPS showed that the difference between active treatment and placebo was statistically significant for the 7 DU group (BPS, P = 0.02; TPS, P = 0.03), with no clear dose–response relationship. All doses of the SQ tree SLIT-tablet induced changes from baseline in birch-specific IgE and IgG4 that were statistically significant compared with placebo at all time points assessed (P < 0.0001) with a clear dose-response relationship for birch specific IgG4. In general, the SQ tree SLIT-tablet was well tolerated, with the majority of treatment-related adverse events (≥95%) being mild or moderate in severity. The most frequently reported treatment-related adverse events were generally related to the sublingual administration of the tablet (ie, they occurred in the oral cavity). ImplicationsThe results from this trial suggest that the SQ tree SLIT-tablet in doses up to 12 DU has a tolerability profile suitable for at-home administration. The immunomodulatory changes indicate a dose–response relationship, but clinical efficacy parameters were inconclusive, probably due to low pollen counts, emphasizing the importance of pollen exposure for the outcome of a pollen allergy immunotherapy trial. EudraCT no: 2012-000031-59.

Comparability between Durham method and real-time monitoring for long-term observation of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Cryptomeria obtusa) pollen counts in Niigata prefecture, Japan

Japanese cedar (Cryptomeria japonica) pollinosis (JCP), affecting more than a quarter of the Japanese population, is a significant public health problem, due to its negative impact on daily activity. JCP patients have used the four-stage daily pollen deposition information based on the pollen monitoring over 20 years. However, the procedure for monitoring pollen was recently changed dramatically, to hourly average pollen concentration monitoring. In that type of monitoring, JCP patients cannot identify pollen exposure level because the relationship between hourly average pollen concentration and daily pollen deposition is unclear. Based on the parallel monitoring of concentration and deposition counts that we performed in Niigata prefecture, Eastern Japan, we found that the relationship between the daily pollen deposition (pollen cm−2 day−1) and the daily-average pollen concentration (pollen m−3) calculated from hourly average pollen concentration was not only statistically significant but also consistent with the aerodynamic properties of pollen. Using the relationship, we proposed new range criteria of hourly average pollen concentrations corresponding to the four stages of pollen deposition. Additionally, the conversion of pollen deposition to pollen concentration made the long-term trend analysis of the daily-average pollen concentration possible in this study area, and an increasing trend was identified at one site.