Important Pollen Allergens Research Articles

Epidemiological investigation of allergic rhinitis in central cities and countrysides of Inner Mongolia region

Objective: To investigate the prevalence of allergic rhinitis (AR) in 3 central cities (Chifeng, Hohhot, Ordos) and the surrounding rural areas of Inner Mongolia region, and to look for possible risk factors related to the disease. Methods: From March to October of 2019, a multi-stage stratified random sampling epidemiological survey was conducted in Chifeng, Hohhot, Ordos and rural areas. The AR-related factors of the population were obtained in the form of face-to-face questionnaire survey, and the skin prick test (SPT) was taken for the participants. AR disease was diagnosed according to the "Guidelines for the Diagnosis and Treatment of Allergic Rhinitis (2015, Tianjin)". The daily airborne pollen situation in the three regions was monitored during the same period. SPSS 23.0 was used to analyze all survey results. Results: A total of 6 818 questionnaires were recovered, with 6 393 valid questionnaires. The self-reported prevalence of AR was 27.72% (1 772/6 393) and the confirmed prevalence of AR was 17.10% (1 093/6 393). The prevalence of perennial AR was 1.83% (117/6 393) while the prevalence of seasonal AR was 15.27% (976/6 393). The prevalence of AR diagnosed in females was higher than that in males (19.19% vs 15.34%, χ²=16.594, P<0.001) and the prevalence of females in the two age groups of 36-45 years and 46-55 years was significantly higher than that of males (18.17% vs 9.73%, 14.13% vs 7.25%, χ2 value was 23.848, 18.772, respectively, all P<0.001). The prevalence of confirmed diagnoses in ethnic minorities was higher than that of Han nationality, and the prevalence of confirmed diagnoses in urban areas was higher than that in rural areas (23.13% vs 16.20%, 27.27% vs 9.71%, χ2 value was 24.516, 336.024, respectively, all P<0.001). The main nasal symptoms of AR patients were sneezing (91.31%), nasal congestion (85.91%) and nasal itching (85.00%). The most common concomitant disease of AR was allergic conjunctivitis (73.99%). Asthma (OR=6.629), food allergy (OR=3.236), drug allergy (OR=1.786), application of antibiotics (OR=1.553), recent home decoration (OR=2.307), and smoking (OR=1.322) were the AR related risk factors. The highest proportion of SPT positive reactions was Artemisia annua (80.15%). The peak period of clinical symptoms of AR patients in Inner Mongolia region was July to September, which was consistent with the second peak period of airborne pollen monitoring. Conclusions: The prevalence of AR in central cities and the surrounding rural areas of Inner Mongolia region is 17.10%, and Artemisia species is the most important pollen allergen in this area. History of asthma, food allergy, drug allergy, antibiotic use, home decoration and smoking history are the related risk factors for AR.

Comparative proteomics of common allergenic tree pollens of birch, alder, and hazel.

BackgroundIn addition to known allergens, other proteins in pollen can aid the development of an immune response in allergic individuals. The contribution of the “unknown” protein allergens is apparent in phylogenetically related species where, despite of high homology of the lead allergens, the degree of allergenic potential can vary greatly. The aim of this study was to identify other potentially allergenic proteins in pollen of three common and highly related allergenic tree species: birch (Betula pendula), hazel (Corylus avellana) and alder (Alnus glutinosa).MethodsFor that purpose, we carried out a comprehensive, comparative proteomic screening of the pollen from the three species. In order to maximize protein recovery and coverage, different protein extraction and isolation strategies during sample preparation were employed.ResultsAs a result, we report 2500–3000 identified proteins per each of the pollen species. Identified proteins were further used for a number of annotation steps, providing insight into differential distribution of peptidases, peptidase inhibitors and other potential allergenic proteins across the three species. Moreover, we carried out functional enrichment analyses that, interestingly, corroborated high species similarity in spite of their relatively distinct protein profiles.ConclusionWe provide to our knowledge first insight into proteomes of two very important allergenic pollen types, hazel and alder, where not even transcriptomics data are available, and compared them to birch. Datasets from this study can be readily used as protein databases and as such serve as basis for further functional studies.

Spatial and temporal variations in the distribution of birch trees and airborne Betula pollen in Ireland

In an Irish context, and indeed in Northern Europe, one of the most important allergenic pollen types is birch (Betula spp.). Thus, forecasts of such atmospheric pollen are important tools for helping patients suffering from allergenic rhinitis and/or atopic asthma to avoid high ambient concentrations and manage their symptoms. This work aims to improve knowledge about the spatial and temporal variations in the distribution of birch trees and airborne Betula pollen in Ireland, which is an important step towards producing such forecasts. The footprint of airborne Betula pollen recorded in Ireland was determined by using HYSPLIT backward Lagrangian dispersion modelling methodology and mapped using Geographic Information System (GIS) software during the Main Pollen Season (MPS) and for days with airborne concentrations > 80 pollen grains/m3 in Dublin and Carlow (72 km apart) for 2018 and 2019. An inventory of birch trees within broadleaved forests was constructed using statistical data from different vegetation inventories for Ireland with a resolution of 100 m x 100 m. Historical datasets of airborne Betula pollen recorded in Dublin during 1978-1980 and 2010-2011 were also related to changes in land cover and climatic conditions over the same period. Dispersion modelling showed that air masses arriving in Ireland on days with Betula pollen concentrations >80 pollen grains/m3 resided for a longer time over Great Britain. The birch tree inventory for Ireland will enhance the performance of forecast models. Airborne Betula pollen concentrations in Ireland have increased over the last 40 years, which is related to concomitant increases in the fraction of birch trees in forest areas as well as the ornamental use of birch trees in urban areas and their reaching maturity. Climate change did not seem to influence birch pollination.

Expression and characterization of recombinant Par j 1 and Par j 2 resembling the allergenic epitopes of Parietaria judaica pollen

The weed wall pellitory, Parietaria judaica, is one the most important pollen allergen sources in the Mediterranean area causing severe symptoms of hay fever and asthma in allergic patients. We report the expression of the major Parietaria allergens, Par j 1 and Par j 2 which belong to the family of lipid transfer proteins, in insect cells. According to circular dichroism analysis and gel filtration, the purified allergens represented folded and monomeric proteins. Insect cell-expressed, folded Par j 2 exhibited higher IgE binding capacity and more than 100-fold higher allergenic activity than unfolded Escherichia coli-expressed Par j 2 as demonstrated by IgE ELISA and basophil activation testing. IgE ELISA inhibition assays showed that Par j 1 and Par j 2, contain genuine and cross-reactive IgE epitopes. IgG antibodies induced by immunization with Par j 2 inhibited binding of allergic patients IgE to Par j 1 only partially. IgE inhibition experiments demonstrated that insect cell-expressed Par j 1 and Par j 2 together resembled the majority of allergenic epitopes of the Parietaria allergome and therefore both should be used for molecular diagnosis and the design of vaccines for allergen-specific immunotherapy of Parietaria allergy.

Airborne pollen calendar of Portugal: a 15-year survey (2002–2017)

IntroductionData about the occurrence of airborne pollen enables the creation of pollen calendars with an approximation of flowering periods for the most common allergenic plant species in a specific area. The aim of this work is to provide pollen calendar for each of the seven monitoring regions of Portugal based on 15 years of airborne sampling, in order to chart the seasonal behaviour of the main allergenic pollen types. Material and methodsAirborne pollen monitoring (2002–2017) was carried out by the Portuguese Aerobiology Network (RPA), using Hirst-type volumetric spore traps, following well-established guidelines. ResultsA total of 14 airborne pollen types were recorded at RPA monitoring stations, of which 64.2% belong to trees, 28.5% to herbs and 7.1% to weeds. The airborne pollen spectrum is dominated by important allergenic pollen types such as Poaceae, Quercus spp., Urticaceae and Cupressaceae. The average pollen index was 42.557 in mainland Portugal and 3.818 in the Islands. There was an increased trend in the airborne pollen levels over the years, namely in Coimbra, Évora and Porto, compared to the remaining regions. ConclusionThis report provides accessible information about the main allergenic airborne pollen types occurring in the course of the year. The pollen calendars charted for each Portuguese region showed that the occurrence of most allergenic taxa was centred from March to July. Pollen peak concentrations were detected earlier in the Centre and Lisbon and Tagus Valley regions, and later in the remaining regions.

Representativeness of pollen traps: a review of the national pollen network of Switzerland

The national pollen network of Switzerland was developed historically. Its 14 pollen traps were placed without considering their representativeness and spatial coverage. The plan for automation of the network gives the motivation for reviewing the network design and to determine the importance and representativeness of each existing monitoring station. Similarities and dissimilarities of the 20-year-long pollen data series (1997–2016) were studied by cluster analysis. Focus was put on the daily course of the pollen season of the seven most important allergenic pollen taxa. The cluster analysis based on correlations of daily pollen concentrations revealed a group of seven similar stations on the Swiss Plateau which differ clearly from the seven stations outside this region. The stations on the Swiss Plateau can be clustered into two subregions, a western and an eastern one. Their correlation coefficients are linearly correlated with distance (from 50 to 300 km). The pattern of the clusters is in good agreement with the division of Switzerland in bioclimatic regions.

Spatial distribution of allergenic pollen through a large metropolitan area.

For nearly a decade, the majority of the world's population has been living in cities, including a considerable percentage of people suffering from pollen allergy. The increasing concentration of people in cities results in larger populations being exposed to allergenic pollen at the same time. There is almost no information about spatial distribution of pollen within cities as well as a lack of information about the possible impact to human health. To obtain this increasing need for pollen exposure studies on an intra-urban scale, a novelty screening network of 14 weekly changed pollen traps was established within a large metropolitan area-Berlin, Germany. Gravimetric pollen traps were placed at a uniform street-level height from March until October 2014. Three important allergenic pollen types for Central Europe-birch (Betula), grasses (Poaceae), and mugwort (Artemisia)-were monitored. Remarkable spatial and temporal variations of pollen sedimentation within the city and the influences by urban local sources are shown. The observed differences between the trap with the overall highest and the trap with the overall lowest amount of pollen sedimentation were in the case of birch pollen 245%, grass pollen 306%, and mugwort pollen 1962%. Differences of this magnitude can probably lead to different health impacts on allergy sufferers in one city. Therefore, pollen should be monitored preferably in two or more appropriate locations within large cities and as a part of natural air quality regulations.

Spatial and temporal variations in the Annual Pollen Index recorded by sites belonging to the Portuguese Aerobiology Network

This study presents the findings of a 10-year survey carried out by the Portuguese Aerobiology Network (RPA) at seven pollen-monitoring stations: five mainland stations (Oporto, Coimbra, Lisbon, Evora and Portimao) and two insular stations [Funchal (Madeira archipelago) and Ponta Delgada (Azores archipelago)]. The main aim of the study was to examine spatial and temporal variations in the Annual Pollen Index (API) with particular focus on the most frequently recorded pollen types. Pollen monitoring (2003–2012) was carried out using Hirst-type volumetric spore traps, following the minimum recommendations proposed by the European Aerobiology Society Working Group on Quality Control. Daily pollen data were examined for similarities using the Kruskal–Wallis nonparametric test and multivariate regression trees. Simple linear regression analysis was used to describe trends in API. The airborne pollen spectrum at RPA stations is dominated by important allergenic pollen types such as Poaceae, Olea and Urticaceae. Statistically significant differences were witnessed in the API recorded at the seven stations. Mean API is higher in the southern mainland cities, e.g. Evora, Lisbon and Portimao, and lower in insular and littoral cities. There were also a number of significant trends in API during the 10-year study. This report identifies spatial and temporal variations in the amount of airborne pollen recorded annually in the Portuguese territory. There were also a number of significant changes in API, but no general increases in the amount of airborne pollen.

Longitudinal Investigation on Allergenic Conifer Pollen in Japan for Successful Prevention and Treatment against Japanese Cedar Pollinosis

Longitudinal Investigation on Allergenic Conifer Pollen in Japan for Successful Prevention and Treatment against Japanese Cedar Pollinosis In Japan allergic people has been recognized increasing according to the increase of Japanese cedar, Cryptomeria japonica (JC) pollinosis since first reported in 1964. We have detected allergenic airborne pollen when Japanese government has begun to investigate the background and treatment on JC pollinosis as a serious social problem since July1986. Urgently the gravitational method with Durham’s sampler has been adopted to know huge number of JC and cypress family, Cupressaceae family (Cypress) pollen grains as causative agent. The area of national artificial forest of over 31 years old has become about 7 times from1970. We have estimated annual fluctuation of Japanese important allergenic pollen, with climatic factor during about 30 years for successful treatment of pollinosis in near future. There are institutions in fifteen locations monitoring airborne pollen by Durham’s sampler in Japan between the latitude of 30 to 40 degrees north. Airborne pollen samples were collected at each institute and were sent to our hospital on a daily basis. We counted pollen grains per cm2 through microscope, classifying and summarizing them. From 1986 to 2014 we have referred to the change in meteorological condition at the close to 9 of the pollen monitoring locations and estimated statically. JC and Cypress pollen counts have shown huge but remarkable annual fluctuation and they have been increasing gradually according to over 31 y-old conifer planting area expanding. The mean temperature in summer time, JC male flower formation, has a significant correlation with next year pollen counts. The pollination season has started earlier in north and later in central Japan gradually through a changing on mean temperature. In Japan allergenic conifer pollen counts have been increasing because of over 31 y-old conifer plantations area increase through the climate change about 30 years. Moreover, it has changed the start of pollination season.

In-print of the environment on the molecular sensitisation profile towards pollen allergens revealed by allergen micro-array

Background The green area in Tashkent-city in Uzbekistan has been re-organized during the last two decades. It covers approximately 35% of the total area and includes classical vegetation present in Central Asia such as saltwort and newly planted species such as Bermuda grass. The knowledge of the molecular sensitization profiles of allergic patients is essential for the correct treatment with allergen specific immunotherapy but has not been established for allergic patients in the Central Asian area. Objective The aim of this study was to determine the IgE-sensitization profile towards pollen allergens in patients with respiratory allergy from Tashkent. Methods Fifty adult patients with allergic rhinitis and/or asthma were tested using an allergen micro-array containing 112 different allergen molecules (ImmunoCAP ISAC; Thermo Scientific). Results We found that the major Bermuda grass pollen allergen, Cyn d 1 and the major saltwort allergen Sal k 1 were most frequently recognized allergens. More than 42% of the patients displayed IgE reactivity to Cyn d 1 and the percentage was even higher in the group suffering from allergic asthma (n=12) (i.e., 66%). Sal k 1 was recognized by 46% of the patients and by 50% of the patients with asthma. The other pollen allergens were recognized less frequently. Interestingly, more than 20% of patients showed IgE cross-reactivity with profilins from grass pollen, weed pollen and birch pollen whereas no patient mounted IgE reactivity to the major birch pollen allergen, Bet v 1. Conclusion The results of the IgE profiling identify grass pollen and in particular Bermuda grass and salkwort as the most important pollen allergen sources in Tashkent. Although approximately 20% of the patients reacted with birch pollen profilin, none of the patients reacted with the major birch pollen allergen, Bet v 1, indicating that these patients had no genuine sensitization to birch. These data show that the molecular sensitization profile towards pollen allergens in Central Asia is an in-print of the local flora and indicates how important allergen micro-array analysis is for the selection of the correct immunotherapy treatment. This study was supported by the Austrian Science Fund (FWF), American Austrian Foundation (AAF) and was performed in the framework of International Network University for Molecular Allergology and Immunology.

Variation in Airborne Fungal Spore Concentrations in Four Different Microclimate Regions in Romania

Airborne fungal counts and types were examined in four regions from Romania. The aim of our study was to determine the concentrations of Alternaria, Cladosporium, Drechslera-type, Epicoccum and Nigrospora atmospheric fungal spores in urban areas: Braşov, Bucharest, Cluj-Napoca and Timişoara. Other objective of this study was to examine the relationships between atmospheric fungal spores and pollen. Few studies have confirmed the high frequency and concentrations for some of these spore types in Romania. The sampling sites differed in habitat characteristics, such as vegetation and microclimate. Airborne spores’ sampling was carried out using the Lanzoni volumetric sampler and during August 2008. The totals of airborne spores recorded in this study show a considerable variation. Cladosporium and Alternaria have been identified as the most abundant and frequent fungal aeroallergens in Timişoara and Bucharest. Drechslera-type, Epicoccum, and Nigrospora had very low values of spore count in all sites. Observations show that seven types of pollen appear regularly and few of these are in great abundance. Fungi are present in the air in concentrations considerably in excess of that of pollen grains. Ambrosia artemisiifolia is the most important pollen allergen in all of the sampled areas discussed here, especially in western country (Timişoara).

Component-resolved diagnosis of peach allergy and its relationship with prevalent allergenic pollens in China

Component-resolved diagnosis of peach allergy and its relationship with prevalent allergenic pollens in China

Passive immunization with allergen-specific IgG antibodies for treatment and prevention of allergy

IgE antibody-mediated allergies affect more than 25% of the population worldwide. To investigate therapeutic and preventive effects of passive immunization with allergen-specific IgG antibodies on allergy in mouse models we used clinically relevant pollen allergens. In a treatment model, mice were sensitized to the major birch pollen allergen Bet v 1 and to the major grass pollen allergens, Phl p 1 and Phl p 5 and then received passive immunization with rabbit IgG antibodies specific for the sensitizing or an unrelated allergen. In a prevention model, mice obtained passive immunization with allergen-specific rabbit IgG before sensitization. Kinetics of the levels of administered IgG antibodies, effects of administered allergen-specific IgG on allergen-specific IgE reactivity, the development of IgE and IgG responses and on immediate allergic reactions were studied by ELISA, rat basophil leukaemia degranulation assays and skin testing, respectively. Treated mice showed an approximately 80% reduction of allergen-specific IgE binding and basophil degranulation which was associated with the levels of administered allergen-specific IgG antibodies. Preventive administration of allergen-specific IgG antibodies suppressed the development of allergen-specific IgE and IgG1 antibody responses as well as allergen-induced basophil degranulation and skin reactivity. Our results show that passive immunization with allergen-specific IgG antibodies is effective for treatment and prevention of allergy to clinically important pollen allergens in a mouse model and thus may pave the road for the clinical application of allergen-specific antibodies in humans.

The dominant 55 kDa allergen of the subtropical Bahia grass (Paspalum notatum) pollen is a group 13 pollen allergen, Pas n 13

Bahia grass, Paspalum notatum, is an important pollen allergen source with a long season of pollination and wide distribution in subtropical and temperate regions. We aimed to characterize the 55kDa allergen of Bahia grass pollen (BaGP) and ascertain its clinical importance. BaGP extract was separated by 2D-PAGE and immunoblotted with serum IgE of a grass pollen-allergic patient. The amino-terminal protein sequence of the predominant allergen isoform at 55kDa had similarity with the group 13 allergens of Timothy grass and maize pollen, Phl p 13 and Zea m 13. Four sequences obtained by rapid amplification of the allergen cDNA ends represented multiple isoforms of Pas n 13. The predicted full length cDNA for Pas n 13 encoded a 423 amino acid glycoprotein including a signal peptide of 28 residues and with a predicted pI of 7.0. Tandem mass spectrometry of tryptic peptides of 2D gel spots identified peptides specific to the deduced amino acid sequence for each of the four Pas n 13 cDNA, representing 47% of the predicted mature protein sequence of Pas n 13. There was 80.6% and 72.6% amino acid identity with Zea m 13 and Phl p 13, respectively. Reactivity with a Phl p 13-specific monoclonal antibody AF6 supported designation of this allergen as Pas n 13. The allergen was purified from BaGP extract by ammonium sulphate precipitation, hydrophobic interaction and size exclusion chromatography. Purified Pas n 13 reacted with serum IgE of 34 of 71 (48%) grass pollen-allergic patients and specifically inhibited IgE reactivity with the 55kDa band of BaGP for two grass pollen-allergic donors. Four isoforms of Pas n 13 from pI 6.3–7.8 had IgE-reactivity with grass pollen allergic sera. The allergenic activity of purified Pas n 13 was demonstrated by activation of basophils from whole blood of three grass pollen-allergic donors tested but not control donors. Pas n 13 is thus a clinically relevant pollen allergen of the subtropical Bahia grass likely to be important in eliciting seasonal allergic rhinitis and asthma in grass pollen-allergic patients.

Rekombinante Allergene

Component-resolved diagnosis of allergies allows disease-specific patterns of sensitization in some conditions such as allergic bronchopulmonary aspergillosis ABPA). By determination of IgE against important pollen allergens such as Bet v 1, Ole e 1 or Phl p1/Phl p 5, more precise guidance for allergen-specific immunotherapy may be achieved, as pollen extracts contain mostly these major allergens. Sensitizations against minor allergens such as profilins or polcalcins influence the outcome of IgE measurements against full allergen sources, but are often of limited clinical relevance. In food allergy, frequent cross reactivity between pollens such as birch pollen via Bet v 1/PR10 proteins can be identified. Sensitization against some storage proteins such as peanut (Ara h 2) or lipid transfer proteins of peach (Pru p 3) or hazelnut (Cor a 8) may indicate an increased risk of severe anaphylactic reactions. Exercise-induced anaphylaxis, unclear sensitizations against latex or double-positivity in insect allergy are other useful indications for component-resolved diagnosis. Microarray-based allergen chip diagnosis makes possible today the detection of IgE against more than 100 allergens in tiny amounts of serum and is very promising, but still needs evaluation and optimization in regard to allergen selection and sensitivity.

The alpha and beta subchain of Amb a 1, the major ragweed-pollen allergen show divergent reactivity at the IgE and T-cell level

Ragweed is one of the most important pollen allergens in North America and parts of Europe. Although the major allergen Amb a 1 was isolated and cloned in 1991, recombinant Amb a 1 was not explored further to improve diagnosis and specific immunotherapy of ragweed-pollen allergy. In the present study the immunological properties of natural Amb a 1 and its proteolytical cleavage products was investigated in detail and compared with recombinant produced Amb a 1 variants.Characterization of natural Amb a 1 and the identification of its proteolytic fragments, designated Amb a 1α and Amb a 1β, was performed by N-terminal sequencing and mass spectroscopy. Amb a 1 and fragments were further produced in Escherichia coli, purified, and immunologically characterized. Amb a 1-specific T-cell cultures were used to compare the T-cell response to the different Amb a 1 variants.Divergent immunological properties of Amb a 1α (aa 181–396) and Amb a 1β (aa 26–180) were revealed. Amb a 1β contained important IgE epitopes, whereas Amb a 1α showed low IgE binding. When compared to natural Amb a 1, all recombinant variants possessed >100-fold reduced IgE-mediated mediator release activity. At the T-cell level recombinant and natural Amb a 1 stimulated comparable T-cell responses and the T-cell reactivity was largely directed to the C-terminal part. The results demonstrated that recombinant Amb a 1α behaves as hypoallergen with reduced IgE binding but preservation of the major T-cell reactivity. In addition, recombinant Amb a 1α can be easily purified to homogeneity in large quantity and therefore represents an ideal candidate for specific immunotherapy.

Evaluation of Cross-Reactivity between Holoptelea integrifolia and Parietaria judaica

Background:Holoptelea integrifolia and Parietaria judaica belong to the family Urticaceae, but are geographically distantly located. H. integrifolia is an important pollen allergen of India and sensitizes almost 10% of the atopic population in Delhi. P. judaica, on the other hand, is a very dominant pollen allergen of the Mediterranean region, sensitizing almost 80% of the allergic population. Since both these important pollen allergens belong to the family Urticaceae, the objective of the present study was to assess cross-reactivity between these two pollen allergens from different geographical regions. Methods: Cross-reactivity between these two pollen allergens was assessed on the basis of skin prick tests and ELISA, ELISA inhibition and immunoblot inhibition studies. Results: Out of 44 atopic Indian patients skin prick tested with H. integrifolia extract, 34% were found to be sensitized. All the patients sensitized to H. integrifolia also showed varying degrees of skin positivity to P. judaica pollen extract. ELISA and ELISA inhibition studies suggested strong cross-reactivity between H. integrifolia and P. judaica pollen. Immunoblot inhibition studies revealed that 14-, 16-, 28-, 38-, 42- and 46-kDa proteins are the cross-reactive proteins in H. integrifolia and P. judaica. However, Par j 1, the major allergen of P. judaica, is absent in H. integrifolia pollen. Conclusion:H. integrifolia and P. judaica pollens share cross-reactive as well as unique epitopes. The major allergen of P. judaica, Par j 1, seems to be absent in H. integrifolia pollen allergen.

P‐42 Pollen allergies in atopic dogs in Buenos Aires (Argentina)

The importance of pollen allergies in dogs with atopic dermatitis in South America has not been determined. Local allergists and pallinologists have performed a few studies evaluating pollen counts in Buenos Aires throughout the year. Those studies helped the author in choosing a pollen allergen panel for intradermal testing based on local allergens. One‐hundred‐sixty dogs with atopic dermatitis were tested intradermally during a 3‐year period, using 30 individual allergens including house dust mites, moulds, trees, weeds and grasses. The most important pollen allergens in terms of positive reactions were Platanus acerifolia (32 dogs), FraxinusAmericana (11 dogs), Cynodon dactylon (13 dogs), Ambrosia tenuifolia (26 dogs), Artemisia spp. (16 dogs), Plantago lanceolata (21 dogs), Chenopodium spp. (16 dogs) and grass pollen (29 dogs). Other pollens on the panel were less important. A correlation between pollination season and atopic dermatitis symptoms was determined. A few dogs were only positive for pollen and not for house dust mites. The incidence of pollen allergies in canine atopic dermatitis in South America must be determined in order to select an adequate panel for the area and for its main cities, and to exclude those allergens that are irrelevant locally. Special individual cases might be further tested, if necessary, with other allergens upon plant identification in the patient's environment. The findings encourage more investigation in this area, and suggest that allergen‐specific immunotherapy with tree, weed and grass pollen should be considered. Funding: Self‐funded.

Ragweed pollen forecasting

Rationale Pollen from Ambrosia species are the most important pollen allergens in North America, and the ability to accurately predict day to day pollen levels could provide important benefit to sensitive individuals. Methods Daily ragweed pollen concentrations from 1987 to 2001 collected with a Burkard spore trap were analyzed to determine pollen season characteristics. Daily concentrations were also compared with data from the National Weather Service to determine the effects of meteorological conditions on airborne pollen levels and to develop an empirical forecasting model. The model was used to predict daily pollen levels during the 2002 ragweed season. Results Pollen data from 1987 to 2001 showed that the mean start date (5% of season total) was 27 Aug; the mean date of the season peak was 10 Sep; and the mean ending date (95% of season total) was 11 Oct. Meteorological parameters used in model development include temperature, relative humidity, wind speed, and rainfall. Forecasts were generated each morning from 1 Sep to 31 Oct and published on the internet at http://pollen.utulsa.edu. Pollen levels were predicted as Low, Moderate, High, and Very High as defined by the National Allergy Bureau. In addition, intermediate levels were also used. Following the ragweed season, forecasts were compared with the daily pollen concentration. Analysis showed that the model successfully predicted pollen severity on 84% of the days during the 2002 ragweed season. Conclusions Pollen forecasting can provide predictions of daily pollen levels and enable sensitive individuals to avoid exposure to high pollen levels or take prophylactic medication.

Pollen count forecasting.

Pollen forecasting is becoming increasingly important to allergists as an adjunct to effective patient care. Forecasts allow patients to avoid exposure to high pollen levels and prompt them to take prophylactic medication and to plan outdoor activities for periods of low pollen levels. Investigators are making progress in developing effective models for daily and seasonal forecasts for important pollen allergens; however, current models are limited to specific geographic areas. Models for the onset of the season for spring tree pollen are based on the chilling and heat units that are required before flowering can occur. Models for pollen season severity are based on regression analysis of preseason meteorologic conditions, and models for daily forecasts are based on the normal pollen curve and responses to day-to-day meteorologic conditions. When winds are favorable, long-distance transport can introduce allergenic pollen types into a local area. The Mountain Cedar Pollen Forecasting model, which combines day-to-day release forecasts at source areas and dispersion forecasts to downwind areas, has been reasonablly successful over the past 4 years. All pollen forecasting models are dependent on accurate meteorologic forecasts, and pollen forecasting will become more accurate as meteorologic forecasts improve.