Allergenic Pollen Grains Research Articles

Allergenic Ambrosia pollen grains in the air of some Polish cities in 2019

Ambrosia is regarded as the most dangerous allergy-related plant posing a considerable threat to human health with its highly allergenic pollen. In Europe, there are 4 Ambrosia species originating from North America; they most often colonize ruderal habitats and agricultural fields. The aim of the study was to compare Ambrosia pollen seasons in 9 cities located in different parts of Poland in 2019. Aerobiological tests were conducted in Bialystok, Bydgoszcz, Lublin, Olsztyn, Piotrkow Trybunalski, Sosnowiec, Szczecin, Warsaw, and Wroclaw. The investigations were carried out with the volumetric method using Burkard or Lanzoni pollen samplers. The 98% method was used to determine the duration of the pollen season. The earliest onset of the pollen season was recorded in Szczecin (August 7th) and Sosnowiec (August 9th), whereas the latest beginning was noted in Wroclaw (August 22nd) and Bydgoszcz (August 21st). The longest pollen season was recorded in Sosnowiec (52 days) as well as Lublin and Szczecin (50 days), while the shortest pollen season was noted in Wroclaw (10 days). The highest mean daily concentrations of Ambrosia pollen grains were recorded in Sosnowiec (104 P/m3) and Wroclaw (77 P/m3), whereas the lowest value was obtained in Szczecin (18 P/m3). Peak days were noted mostly during the last 10 days of August. The highest value of Ambrosia annual pollen sum was reported from Sosnowiec (326) and Lublin (310), while the lowest sum was noted in Szczecin (69). The multimodal course of the graph presenting the pollen seasons in the analysed cities and literature data indicate that the pollen originated not only from local sources but also from long-distance transport. The highest risk of Ambrosia pollen-induced allergy in sensitive subjects was demonstrated in Lublin, Piotrkow Trybunalski and Warsaw. The concentration of Ambrosia pollen in the air of the analysed Polish cities was substantially lower than the values indicated by measurement stations located in other parts of Europe.

Predicting abundances of invasive ragweed across Europe using a “top-down” approach

Common ragweed (Ambrosia artemisiifolia L.) is a widely distributed and harmful invasive plant that is an important source of highly allergenic pollen grains and a prominent crop weed. As a result, ragweed causes huge costs to both human health and agriculture in affected areas. Efficient mitigation requires accurate mapping of ragweed densities that, until now, has not been achieved accurately for the whole of Europe. Here we provide two inventories of common ragweed abundances with grid resolutions of 1 km and 10 km. These “top-down” inventories integrate pollen data from 349 stations in Europe with habitat and landscape management information, derived from land cover data and expert knowledge. This allows us to cover areas where surface observations are missing. Model results were validated using “bottom–up” data of common ragweed in Austria and Serbia. Results show high agreement between the two analytical methods. The inventory shows that areas with the lowest ragweed abundances are found in Northern and Southern European countries and the highest abundances are in parts of Russia, parts of Ukraine and the Pannonian Plain. Smaller hotspots are found in Northern Italy, the Rhône Valley in France and in Turkey. The top-down approach is based on a new approach that allows for cross-continental studies and is applicable to other anemophilous species. Due to its simplicity, it can be used to investigate such species that are difficult and costly to identify at larger scales using traditional vegetation surveys or remote sensing. The final inventory is open source and available as a georeferenced tif file, allowing for multiple usages, reducing costs for health services and agriculture through well-targeted management interventions.

The Most Common Allergenic Tree Pollen Grains in the Middle East: A Narrative Review.

Allergy is becoming a major disease burden globally. Pollens are considered as the main component of aeroallergens that lead to rhinitis and asthma. Due to the lack of a comprehensive investigation on most allergic pollens of trees in the Middle East, the present study aimed to conduct a comprehensive literature review on this topic. The main goal of the study was to provide a checklist for allergists and patients to easily identify the commonest allergic pollens in their locality. The present review provides a broad range of information on the types and geographic locations of the most common allergic pollens of trees in each studied country. In general, among the 23 studied countries, palm and mesquite trees were the common producers of pollen allergen in the Persian Gulf region. Olive tree is common in Turkey, Palestine, and Israel, whereas sycamore tree is the common allergen pollen in Iran. Considering the uneven geographical distribution of these trees in the world, allergists are unable to accurately select the appropriate extracts for the skin prick test based on the information from the neighboring countries. This scenario becomes more complicated if one adds the imported ornamental trees in the picture.

Free orbicules of Cupressaceae detected in daily aerobiological samples by optical and confocal microscopy

Members of Cupressaceae and Taxaceae are known to release large amounts of highly allergenic pollen grains into the atmosphere, which are responsible for the onset of pollinosis in many countries throughout the world. In addition to pollen grains, their pollen sacs produce orbicules, which are submicron particles reported to carry allergens and which are potentially able to reach much further down the respiratory tract than pollen grains. Previous research has postulated the presence of orbicules in the atmosphere; however, direct observations have not yet been reported. The aim of this research was to provide the first direct evidence that Cupressaceae orbicules are released into the atmosphere by detecting them in daily aerobiological samples. We observed pollen sacs, pollen grains, and orbicules of nine species of Cupressaceae using scanning electron microscope (SEM). We then used a light and confocal microscope, to examine daily aerobiological samples. Under SEM, we measured the orbicule size (0.494–0.777 µm) and detected unknown nanometric particles (130–200 nm). Under the light microscope, aerobiological samples showed clusters of stained dots surrounding the pollen grains of Cupressaceae. Under the confocal microscope, the same clusters were resolved into submicron particles with the same autofluorescence as the pollen grains. These features enabled us to identify them as orbicules. We believe that our findings help to explain the onset of pollinosis and allergic asthma related to Cupressaceae pollen grains in many countries, even before pollen grains are actually detected or after they are no longer observed in aerobiological monitoring samples.

Health hazards related to conidia of Cladosporium—biological air pollutants in Poland, central Europe

The spores of Cladosporium Link. are often present in the air in high quantities and produce many allergenic proteins, which may lead to asthma. An aerobiological spore monitoring program can inform patients about the current spore concentration in air and help their physicians determine the spore dose that is harmful for a given individual. This makes it possible to develop optimized responses and propose personalized therapy for a particular sensitive patient. The aim of this study was to assess the extent of the human health hazard posed by the fungal genus Cladosporium. For the first time, we have determined the number of days on which air samples in Poland exceeded the concentrations linked to allergic responses of sensitive patients, according to thresholds established by three different groups (2800/3000/4000 spores per 1m3 of the air). The survey was conducted over three consecutive growing seasons (April–September, 2010–2012) in three cities located in different climate zones of Poland (Poznan, Lublin and Rzeszow). The average number of days exceeding 2800 spores per cubic meter (the lowest threshold) ranged from 61 (2010) through 76 (2011) to 93 (2012), though there was significant variation between cities. In each year the highest concentration of spores in the air was detected in either Poznan or Lublin, both located on large plains with intensive agriculture. We have proposed that an effective, science-based software platform to support policy-making on air quality should incorporate biological air pollutant data, such as allergenic fungal spores and pollen grains.

Quantitative DNA Analyses for Airborne Birch Pollen.

Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR), which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm) and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8) and the other for a multi-copy gene (ITS). The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm), the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

Potential impact of climate change on fungal distributions: analysis of 2 years of contrasting weather in the UK

The impact of climate change on fungal growth and spore production is less well documented than for allergenic pollen grains, although similar implications for respiratory tract diseases in humans occur. Fungal spores are commonly described as either “dry” or “wet” according to the type of weather associated with their occurrence in the air. This study examined the distribution of selected fungal spores (Alternaria spp., Cladosporium spp., Didymella spp., Epicoccum spp., Leptosphaeria spp. and rusts) occurring in the West Midlands of UK during 2 years of contrasting weather. Spore specimens were collected using a 7-day volumetric air sampler and then analysed with the aid of light microscopy. Distributions of spores were then studied using normality tests and Mann–Whitney U test, while relationships with meteorological parameters were investigated using Spearman’s rank test and angular-linear correlation for wind direction analysis. Our results showed that so-called wet spores were more sensitive to the weather changes showing statistically significant differences between the 2 years of study, in contrast to “dry” spores. We predict that in following years we will observe accelerated levels in allergenic fungal spore production as well as changes in species diversity. This study could be a starting point to revise the grouping system of fungal spores as either “dry” or “wet” types and their response to climate change

Biomonitoring of pollen grains of a river bank suburban city, Konnagar, Calcutta, India, and its link and impact on local people.

Pollen grains released by plants are dispersed into the air and can become trapped in human nasal mucosa, causing immediate release of allergens triggering severe Type 1 hypersensitivity reactions in susceptible allergic patients. Recent epidemiologic data show that 11-12% of people suffer from this type of disorders in India. Hence, it is important to examine whether pollen grains have a role in dissipating respiratory problems, including allergy and astma, in a subtropical suburban city. Meteorological data were collected for a period of two years, together with aerobiological sampling with a Burkard sampler. A pollen calendar was prepared for the city. A health survey and the hospitalization rate of local people for the above problems were documented following statistical analysis between pollen counts and the data from the two above-mentioned sources. Skin Prick Test and Indirect ELISA were performer for the identification of allergenic pollen grains. Bio-monitoring results showed that a total of 36 species of pollen grains were located in the air of the study area, where their presence is controlled by many important meteorological parameters proved from SPSS statistical analysis and by their blooming periods. Statistical analysis showed that there is a high positive correlation of monthly pollen counts with the data from the survey and hospital. Biochemical tests revealed the allergic nature of pollen grains of many local species found in the sampler. Bio-monitoring, together with statistical and biochemical results, leave no doubt about the role of pollen as a bio-pollutant. General knowledge about pollen allergy and specific allergenic pollen grains of a particular locality could be a good step towards better health for the cosmopolitan suburban city.

Feasibility of Ceiling-Mounted Assist Device of Air-Purifier for Removal of Airborne Allergic Pollen Grains

Feasibility of a ceiling-mounted assist device of the air-purifier for removal of airborne allergenic pollen grains is investigated by both turbulent flow and particle-tracking calculations. The device is mounted straight above the air-purifier and it collects suspended pollen grains in the exhaust flow of the air-purifier. It is found from the turbulent flow calculation that the flow rate of the assist device should be larger than that of the air-purifier. Otherwise the upward air flows around the assist device, and pollen grains move along the surrounding flow; they are never removed from the air. We also found about 40% improvement of the pollen removal efficiency by installing the assist device.

Current glimpse of airborne allergenic pollen in Indian subcontinent

Respiratory allergic diseases such as bronchial asthma, rhinitis, urticaria, atopic dermatitis have been steadily increasing all over the world, including India. Owing to its alarming trend, several aerobiological surveys have been undertaken in different parts of India to delineate the variety of pollen and spore load. In this review, we have reported the current state of aerobiological knowladge in India with particular reference to allergenic airborn pollen occurence in 2001–2015. Pollen have been found to contribute a significant proportion in the air and caused allergy symptoms in the local inhabitants. Aerobiological records, a questionnaire survey and hospitalization records have been employed for the analysis. &lt;em&gt;Holoptelea integrifolia&lt;/em&gt;, &lt;em&gt;Amaranthus spinosus&lt;/em&gt; in northern region, &lt;em&gt;Sorghum vulgare&lt;/em&gt;, &lt;em&gt;Pennisetum&lt;/em&gt;, &lt;em&gt;Gynandropsis gynandra&lt;/em&gt;, &lt;em&gt;Parthenium hysterophorus&lt;/em&gt;, &lt;em&gt;Dolichandrone platycalyx&lt;/em&gt; in southern regions, and &lt;em&gt;Parthenium hysterophorus&lt;/em&gt; from the western region; &lt;em&gt;Cynodon dactylon&lt;/em&gt;, &lt;em&gt;Cenchrus ciliaris&lt;/em&gt; in the central area; &lt;em&gt;Acacia auriculiformis&lt;/em&gt;, &lt;em&gt;Cleome gynandra&lt;/em&gt;, &lt;em&gt;Catharanthus roseus&lt;/em&gt;, &lt;em&gt;Phoenix sylvestris&lt;/em&gt;, &lt;em&gt;Areca catechu&lt;/em&gt;, and &lt;em&gt;Lantana camara&lt;/em&gt; in the eastern regions as potential aeroallergens in India. The statistical approach confirmed the correlation between hospitalization rate associated with allergy-related health troubles and the prevalent allergenic pollen in the air. The Poaceae group has been found to be dominant throughout India. Immuno-biochemical studies identified various protein with allergenic potential found in the pollen recorded. Epitope identification and homology of the major allergenic protein Cat r1 of &lt;em&gt;Catharanthus&lt;/em&gt; sp and Par j 1 of &lt;em&gt;Parietaria judaica&lt;/em&gt; have been found. Identification of allergenic pollen grains and the modern approach concerning cross-reactivity and epitope revelation of dominant airborne pollen have important clinical implications for the prevention, diagnosis and treatments of allergic diseases in India.

Pollen monitoring in Perm Krai (Russia) – experience of 6 years

Medical observations show that the level of pollinosis increased by 34.6% in central Russia in 2005–2012. This paper presents the results of 6-year pollen monitoring carried out with a Hirst-type pollen trap (Burkard Manufacturing Co. Ltd) between 2010 and 2015 in Perm Krai (Russia). Usually, sensitization of allergic people occurs in three periods: (i) spring due to the pollen of &lt;em&gt;Betula&lt;/em&gt;, (ii) early summer due to Poaceae pollen, and (iii) late summer as a result of &lt;em&gt;Artemisia&lt;/em&gt; pollen. &lt;em&gt;Betula&lt;/em&gt; pollen, which is dominant (26.9–65.2% of total pollen counts), is recorded in large numbers in the period of flowering and occasionally during the entire period of pollination. Among herbaceous plants, the pollen of Poaceae, Urticaceae and &lt;em&gt;Artemisia&lt;/em&gt; dominates in airborne pollen. The concentration of allergenic pollen grains in the air of Perm Krai is lower than in other European geographical regions.

Identification of allergenic pollen grains in 36 olive (Olea europaea) cultivars grown in Jordan

Inhalation of olive pollen is a major cause of allergic respiratory diseases in Mediterranean region. Using bags attached to the branches, pollens were collected from 36 olive cultivars grown in Jordan just before bloom. Proteins were extracted from pollens and analysed by SDS-PAGE and immunoblotting using antisera collected from patients with history of olive pollen-allergy. Immunoblot results showed that 25 cultivars contained one or two allergenic proteins in the range of 15–72 kDa with majority of the proteins corresponding to 15–20 kDa, while remainders did not exhibit any allergenic protein. Seven cultivars exhibited three allergenic proteins and only two cultivars exhibited four allergenic proteins and thus, were considered potentially hyperallergenic cultivars. This study highlights the great variability in the antigenic and allergenic composition of Olea europaea pollen extracts which may serve as guidance for selecting the olive tree cultivars that could be planted in urban areas.

An assessment of the air quality in indoor and outdoor air with reference to fungal spores and pollen grains in four working environments in Kerala, India

Qualitative and quantitative analyses of airborne fungal spores and pollen grains in four working environments (market, saw mill, poultry and cow sheds) in Thiruvananthapuram, the capital city of Kerala, India, were carried out for 2 years using Burkard Personal Slide Sampler and Andersen Two-Stage Sampler. Total spore concentration in these sites was always higher in indoor environments than in outdoor environments. Difference in concentration was not statistically significant in any of these work places except in saw mill (t test, p < 0.05). The highest spore concentration was recorded here followed by market, poultry and cow sheds. A total of 32 fungal spore types from indoor environments and 33 spore types from outdoor environments were recorded. Of them, 16 spore types were common to all the sites. Ameropsores, Cladosporium, other basidiospores, Ganoderma and Nigrospora were the dominant spore types in both indoor and outdoor environments. A total of 27 species of viable fungi from indoor and 24 species from outdoor environments were identified. Penicillium citrinum, Aspergillus flavus and Aspergillus niger were the most dominant viable fungi isolated. In contrast, total pollen concentration was always higher in outdoor environments than in indoor environments. Twenty-nine pollen types from indoor and 32 pollen types from outdoor were captured during the sampling. Poaceae, Cocos, Artocarpus, Amaranthus/Chenopodium and Tridax were the common and dominant pollen types observed in all the sites. Peak spore and pollen incidence were recorded during the late rainy and dry seasons (October–February) in both indoor and outdoor environments. The study revealed high prevalence of predominantly allergenic fungal spores and pollen grains in all the four work places. Workers/visitors are at potential risk of susceptibility to respiratory/allergic disorders.

Co-occurrence of airborne allergenic pollen grains and fungal spores in Rzeszów, Poland (2000-2002)

The co-occurrence of airborne allergenic pollen grains and fungal spores was estimated in Rzeszów in the years 2000-2002. The volumetric method was used in this aerobiological study. Six taxa of pollen grains and five types of fungal spores characterized by strong allergenicity and/or high concentrations in the air were analyzed. The time series of pollen grains and fungal spores were compared using PCA analysis. The periods of the greatest concentrations of tree pollen did not coincide with similar periods for herbaceous plants and fungal spores. From February to mid-March, &lt;i&gt;Alnus&lt;/i&gt; pollen dominated in the air. The second period was characterized by &lt;i&gt;Betula&lt;/i&gt; pollen. It occurred in April. Herbaceous pollen and fungal spores occurred in the air simultaneously (from mid May to the end of August), creating a risky situation for sensitized people. The periods of the highest concentrations of &lt;i&gt;Epicoccum&lt;/i&gt; and &lt;i&gt;Ganoderma&lt;/i&gt; fungal spores did not coincide with the same period for the examined plant taxa. In Rzeszów the probability of becoming exposed to very high concentrations of allergenic pollen and fungal spores at the same time was high, especially in July, when the highest concentrations of Poaceae, &lt;i&gt;Alternaria&lt;/i&gt; and &lt;i&gt;Cladosporium&lt;/i&gt; were noted. The hypersensitivity to only one plant or fungal allergen is rarely encountered. Under the present scenarios of global warming, pollen seasons of many taxa will be longer and sufferers will have year-long symptoms.

Flowering and airborne pollen - a novel statistical approach

The time pattern of flowering significantly affects the pollen season, its beginning, length and the concentration of pollen grains in air. The forecasting models used in aerobiological studies were chiefly based on the elements of weather conditions; however, recently the phenology of pollen shedding has been taken into consideration in these models more and more frequently. The aim of the presented investigations was to determine to what extent the flowering and the occurrence of allergenic pollen grains in air coincided in time. The investigation was carried out in Rzeszów (SE Poland) in the years 2003-2004. The flowering of 19 allergenic plant species was observed and seven phenophases were distinguished. Aerobiological monitoring was based on the volumetric method. In the case of most herbaceous plants, the flowering period overlapped the pollen season, high concentrations of pollen being recorded throughout several phenophases. In general, the pollen of trees occurred during very short periods, frequently during one phenophase, while the investigated phenomena were missing each other. The most intensive growth of inflorescences of alder, hazel and birch was observed at the beginning of full fl owering or towards the end of full flowering.

Seasonal distribution of airborne pollen in Ulsan, Korea in 2009-2010

To determine the peak dispersal times of allergenic pollen grains in Ulsan, Korea, we performed continuous airborne pollen counts at three stations (Sts. A, B, and C) in Ulsan from August 2009 to November 2010. Pollen grains were sampled using a Durham sampler. Two peak pollen dispersal seasons were observed per year. The peak seasons generally coincided with the flowering period of anemophilous trees: Taxodiaceae (February), Alnus (March), Cupressaceae (April), Quercus, and Pinus (May), and with the flowering phase of herbs from August to November, e.g., Humulus, Artemisia, Gramineae, and Ambrosia from August through September. The highest concentration of airborne pollen was from Pinus (68%), followed by Quercus (15%), Alnus (6%), and Humulus (2%); whereas very low pollen concentrations were from Taxodiaceae, Cupressaceae, Artemisia, Gramineae, and Ambrosia (<TEX>${\leq}$</TEX> 1% of the annual total airborne pollen concentration). Our findings indicate that Alnus and Humulus pollen are major allergens whereas those of Pinus and Quercus are minor allergens. The concentration of Alnus pollen grains at St. C was over five times that at Sts. A and B. This finding implies that individuals living at or near St. C are exposed to high concentrations of Alnus pollen before and after March, which is the flowering period of the alder tree. From August to September, individuals living at or near St. B are exposed to high concentrations of Humulus pollen. Our study suggests that Alnus pollen may be the major aeroallergen causing pollinosis in the spring at St. C and Humulus pollen may be the major aeroallergen in autumn at St. B.

NADPH oxidase activity in allergenic pollen grains of different plant species

Pollen is an important trigger of allergic diseases. Recent studies have shown that ragweed pollen NAD(P)H oxidase generates reactive oxygen species (ROS) and plays a prominent role in the pathogenesis of allergies in mouse models. Here, we demonstrated that allergenic pollen grains showed NAD(P)H oxidase activity that differed in intensity and localization according to the plant families. The activity occurred at the surface or in the cytoplasm in pollen of grasses, birch, and ragweed; in subpollen particles released from ragweed pollen; and at the inner surface or in the cytoplasm but not on the outer wall, which was sloughed off after the rupture, of pollen of Japanese cedar and Japanese cypress. The activity was mostly concentrated within insoluble fractions, suggesting that it facilitates the exposure of tissues to ROS generated by this enzyme. The extent of exposure to pollen-generated ROS could differ among the plant families.

Seed hairs of poplar trees as natural airborne pollen trap for allergenic pollen grains

The present article deals with the efficacy of seed hairs of poplar trees (Populus spp.) as a potent natural airborne pollen trap. Different species of Populus are commonly found planted along the streets in the cities of North China. The seed hairs and pericarp of poplar trees were collected from the trees and on the ground in Beijing Botanical Garden of Chinese Academy of Sciences and around Miyun Reservoir during May 2005 for pollen analysis. Different pollen spectra are recorded from different samples and are characterised by dominant occurrence of pollen grains of arboreal and anemophilous plants. In addition, pollen grains of non‐arboreal plants including grasses are also found trapped. Among the 46 trapped pollen grains, 26 are known to be allergenic. This study suggests that poplar seed hairs possibly make people feel uncomfortable due to the presence of allergenic pollen trapped in the hairs.

Prevalence of allergenic pollen grains in the aerosol of the city of Calcutta, India: a two year study

The role of pollen grains as a causative agent of respiratory allergic disorders such as asthma and allergic rhinitis is common and very well established. The aim of this study was to assess the frequencies of airborne pollen in the Calcutta metropolis and to identify the taxa which cause significant amounts of sensitization. An aeropalynological survey of the atmosphere of Calcutta was carried out from 2004 to 2006. Skin tests were performed with a panel of the most common pollen types on local patients with clinical features of pollinosis. The meteorological factors responsible for the frequency of the pollen types were analysed. The results of monthly visits to the clinic by these patients were correlated with the monthly pollen counts of three dominant and perennial pollen taxa. The dominant pollen types were Trema (19%), Poaceae (12.98%), Casuarina (5.76%), Cocos (5.7%), Azadirachta (4.65%), Peltophorum (3.71%), Cyperaceae (3.68%), Delonix (3.18%) and Areca (2.56%). Total pollen concentration seems to have a significant positive correlation with temperature and wind speed whereas there was a negative correlation with humidity. Skin tests were most frequently found to be positive with the pollen of Poaceae (49%), Azadirachta (46%), Cocos (47%), Cyperaceae (35%), Peltophorum (33%), Areca (29%), Phoenix (26%), and Borassus (23%). A positive correlation occurred between visits to the clinic and monthly pollen count of Areca, Cocos, and Poaceae. This is the first study to design a pollen calendar for Calcutta city; it will provide useful data for enabling allergologists to achieve accurate diagnosis for patients with pollen hypersensitivity.

Characterization of Proteases, Proteins, and Eicosanoid-Like Substances in Soluble Extracts from Allergenic Pollen Grains

Background: Pollen is an important trigger of seasonal rhinitis, conjunctivitis, and/or allergic asthma, and an exacerbating factor in atopic dermatitis. Pollen grains contain allergen proteins, enzymes, and bioactive lipid mediators, the latter two possibly involved in the pathogenesis of allergic diseases through IgE-independent mechanisms. Methods: We analyzed the patterns of release of endopeptidases from allergenic pollen of Japanese cedar, Japanese cypress, and Rocky mountain juniper, which belong to the Cupressaceae/Taxodiaceae family, and birch, ragweed, and two grasses, Kentucky blue and cultivated rye, using synthetic substrates, class-specific inhibitors, and zymography. The proteins released were analyzed by gel electrophoresis. Eicosanoid-like substances were measured by enzyme-linked immunosorbent assays for prostaglandin E₂ and leukotriene B₄. Results: Major fractions of proteins, eicosanoid-like substances, and at least one molecular species of serine endopeptidase were released into phosphate-buffered saline from the pollen grains at 37°C within 25 min or 60 min without sonication. In the Cupressaceae/Taxodiaceae family, sonication was necessary for the release of other proteins and another serine endopeptidase. In birch, ragweed, and the grasses, most of the serine and cysteine endopeptidases were released without sonication. Proteases released within 25 min digested gelatin and/or casein differently among plant species. Conclusions: Grains of allergenic pollen release proteases, which can digest not only short synthetic substrates but also protein substrates, along with eicosanoid-like substances and proteins. The release of these components could contribute to the formation of a microenvironment optimum for initiation of the sensitization or the exacerbation of pollen allergy in tissues exposed to pollen grains.