Allergenic pollen and pollen allergy in Europe

Human IgE against the major allergen Bet v 1--defining an epitope with limited cross-reactivity between different PR-10 family proteins

Background

The interaction between IgE and allergen is a key event at the initiation of an allergic response, and its characteristics have substantial effects on the clinical manifestation. Despite this, the molecular details of the interaction between human IgE and the major birch allergen Bet v 1, one of the most potent tree allergens, still remain poorly investigated.

Objective

To isolate Bet v 1-specific human monoclonal IgE and characterize their interaction with the allergen.

Methods

Recombinant human IgE were isolated from a combinatorial antibody fragment library and their interaction with Bet v 1 assessed using various immunological assays. The structure of one such IgE in the single-chain fragment variable format was determined using X-ray crystallography.

Results

We present four novel Bet v 1-specific IgE, for one of which we solve the structure, all with their genetic origin in the IGHV5 germline gene, and demonstrate that they target two non-overlapping epitopes on the surface of Bet v 1, thereby fulfilling the basic criteria for FcεRI cross-linkage. We further define these epitopes and for one epitope pinpoint single amino acid residues important for the interaction with human IgE. This provides a potential explanation, at the molecular level, for the differences in recognition of isoforms of Bet v 1 and other allergens in the PR-10 protein family displayed by IgE targeting this epitope. Finally, we present the first high-resolution structure of a human allergen-specific IgE fragment in the single-chain fragment variable (scFv) format.

Conclusions and Clinical Relevance

We here display the usefulness of allergen-specific human monoclonal IgE as a tool in studies of the crucial molecular interaction taking place at the initiation of an allergic response. Such studies may aid us in development of better diagnostic tools and guide us in the development of new therapeutic compounds.

Short-term preseasonal immunotherapy: is early clinical efficacy related to the basophil response?

BACKGROUND

An aluminum hydroxide-adsorbed depot allergoid preparation of six-grass pollen allergens has been developed for short-term preseasonal immunotherapy in pollinosis. However, only limited knowledge exists about its immunological and clinical effects. The aim of this study was to evaluate the basophil response, which can explain early clinical findings of short-term preseasonal allergoid immunotherapy in allergic rhinitis.

METHODS

In a double-blind, placebo-controlled study, 31 patients allergic to grass pollens received one course of short-term preseasonal allergoid immunotherapy or placebo. Immunogenicity was assessed by the levels of specific IgG4, IgE antibodies and an allergen-induced CD203c basophil activation test. The primary clinical end point was the combined symptom and medication score/average combined score (ACS).

RESULTS

There was a 52.9% difference in ACS between the treatment and placebo groups in favor of immunotherapy (p = 0.01). Active treatment induced Phleum pratense-specific IgG4 and IgE antibodies (p < 0.05). A decrease in allergen-induced basophil activation at submaximal allergen concentrations was demonstrated at the end of immunotherapy and at the peak of the grass pollen season after immunotherapy.

CONCLUSIONS

This study shows that grass pollen-allergic patients treated with one course of short-term preseasonal allergoid immunotherapy exhibit a decrease in allergen-induced basophil activation, an increase in allergen-specific IgG4 antibodies and early clinical improvement.

Loop-mediated isothermal amplification of single pollen grains

The polymerase chain reaction (PCR) has been a reliable and fruitful method for many applications in ecology. Nevertheless, unavoidable technical and instrumental requirements of PCR have limited its widespread application in field situations. The recent development of isothermal DNA amplification methods provides an alternative to PCR, which circumvents key limitations of PCR for direct amplification in the field. Being able to analyze DNA in the pollen cloud of an ecosystem would provide very useful ecological information, yet would require a field-enabled, high-throughput method for this potential to be realized. Here, we demonstrate the applicability of the loop-mediated DNA amplification method (LAMP), an isothermal DNA amplification technique, to be used in pollen analysis. We demonstrate that LAMP can provide a reliable method to identify species from the pollen cloud, and that it can amplify successfully with sensitivity down to single pollen grains, thus opening the possibility of field-based, high-throughput analysis.

Recombinant allergens for pollen immunotherapy

Specific immunotherapy (IT) represents the only potentially curative therapeutic intervention of allergic diseases capable of suppressing allergy-associated symptoms not only during treatment, but also after its cessation. Presently, IT is performed with allergen extracts, which represent a heterogeneous mixture of allergenic, as well as nonallergenic, compounds of a given allergen source. To overcome many of the problems associated with extract-based IT, strategies based on the use of recombinant allergens or derivatives thereof have been developed. This review focuses on recombinant technologies to produce allergy therapeuticals, especially for allergies caused by tree, grass and weed pollen, as they are among the most prevalent allergic disorders affecting the population of industrialized societies. The reduction of IgE-binding of recombinant allergen derivatives appears to be mandatory to increase the safety profile of vaccine candidates. Moreover, increased immunogenicity is expected to reduce the dosage regimes of the presently cumbersome treatment. In this regard, it has been convincingly demonstrated in animal models that hypoallergenic molecules can be engineered to harbor inherent antiallergenic immunologic properties. Thus, strategies to modulate the allergenic and immunogenic properties of recombinant allergens will be discussed in detail. In recent years, several successful clinical studies using recombinant wild-type or hypoallergens as active ingredients have been published and, currently, novel treatment forms with higher safety and efficacy profiles are under investigation in clinical trials. These recent developments are summarized and discussed.

Childhood intermittent and persistent rhinitis prevalence and climate and vegetation: a global ecologic analysis

BACKGROUND

The effect of climate change and its effects on vegetation growth, and consequently on rhinitis, are uncertain.

OBJECTIVE

To examine between- and within-country associations of climate measures and the normalized difference vegetation index with intermittent and persistent rhinitis symptoms in a global context.

METHODS

Questionnaire data from 6- to 7-year-olds and 13- to 14-year-olds were collected in phase 3 of the International Study of Asthma and Allergies in Childhood. Associations of intermittent (>1 symptom report but not for 2 consecutive months) and persistent (symptoms for ≥2 consecutive months) rhinitis symptom prevalences with temperature, precipitation, vapor pressure, and the normalized difference vegetation index were assessed in linear mixed-effects regression models adjusted for gross national income and population density. The mean difference in prevalence per 100 children (with 95% confidence intervals [CIs]) per interquartile range increase of exposure is reported.

RESULTS

The country-level intermittent symptom prevalence was associated with several country-level climatic measures, including the country-level mean monthly temperature (6.09 °C; 95% CI, 2.06-10.11°C per 10.4 °C), precipitation (3.10 mm; 95% CI, 0.46-5.73 mm; per 67.0 mm), and vapor pressure (6.21 hPa; 95% CI, 2.17-10.24 hPa; per 10.4 hPa) among 13- to 14-year-olds (222 center in 94 countries). The center-level persistent symptom prevalence was positively associated with several center-level climatic measures. Associations with climate were also found for the 6- to 7-year-olds (132 center in 57 countries).

CONCLUSION

Several between- and within-country spatial associations between climatic factors and intermittent and persistent rhinitis symptom prevalences were observed. These results provide suggestive evidence that climate (and future changes in climate) may influence rhinitis symptom prevalence.

Hypersensitivity to aeroallergens in patients with nasobronchial allergy

Background:

Aeroallergens are the most common causes of allergy.

Aim:

The aim of this study was to determine hypersensitivity to aeroallergens in patients with nasobronchial allergy.

Methods:

This retrospective population study included 2254 patients with nasobronchial allergy, from late adolescents to adults. Their response to aeroallergens was assessed by skin prick tests.

Results:

More patients had rhinitis (72.7%), than asthma (27.6%). Although majority of patients were female, allergy is more common in men than in women (p<0.05). Both groups of patients had the greatest number of positive skin prick tests for Dermatophagoides pteronyssinus (27.5%) and weed pollens (21.9%), followed by grass (18.3%) and tree pollens (10.1%). Ragweed is the most common positive weed pollen in both groups, more in patients with rhinitis (p=0.022). The cocksfoot is the most common grass pollen in rhinitis group (15.3%), but meadow grass (12.6%) in asthma patients. Birch is the most common tree allergen in the both groups.

Conclusions:

More patients with nasobronchial allergy have rhinitis than asthma. Skin prick tests are usually positive for Dermatophagoides pteronyssinus and weed pollens, followed by grass and tree pollens, and they are more common positive in patients with rhinitis than asthma.

Design of a downscaling method to estimate continuous data from discrete pollen monitoring in Tunisia

The study of microorganisms and biological particulate matter that transport passively through air is very important for an understanding of the real quality of air. Such monitoring is essential in several specific areas, such as public health, allergy studies, agronomy, indoor and outdoor conservation, and climate-change impact studies. Choosing the suitable monitoring method is an important step in aerobiological studies, so as to obtain reliable airborne data. In this study, we compare olive pollen data from two of the main air traps used in aerobiology, the Hirst and Cour air samplers, at three Tunisian sampling points, for 2009 to 2011. Moreover, a downscaling method to perform daily Cour air sampler data estimates is designed. While Hirst air samplers can offer daily, and even bi-hourly data, Cour air samplers provide data for longer discrete sampling periods, which limits their usefulness for daily monitoring. Higher quantities of olive pollen capture were generally detected for the Hirst air sampler, and a downscaling method that is developed in this study is used to model these differences. The effectiveness of this downscaling method is demonstrated, which allows the potential use of Cour air sampler data series. These results improve the information that new Cour data and, importantly, historical Cour databases can provide for the understanding of phenological dates, airborne pollination curves, and allergenicity levels of air.

Poaceae pollen in the air depending on the thermal conditions

The relationship between the meteorological elements, especially the thermal conditions and the Poaceae pollen appearance in the air, were analysed as a basis to construct a useful model predicting the grass season start. Poaceae pollen concentrations were monitored in 1991-2012 in Kraków using the volumetric method. Cumulative temperature and effective cumulative temperature significantly influenced the season start in this period. The strongest correlation was seen as the sum of mean daily temperature amplitudes from April 1 to April 14, with mean daily temperature>15 °C and effective cumulative temperature>3 °C during that period. The proposed model, based on multiple regression, explained 57% of variation of the Poaceae season starts in 1991-2010. When cumulative mean daily temperature increased by 10 °C, the season start was accelerated by 1 day. The input of the interaction between these two independent variables into the factor regression model caused the increase in goodness of model fitting. In 2011 the season started 5 days earlier in comparison with the predicted value, while in 2012 the season start was observed 2 days later compared to the predicted day. Depending on the value of mean daily temperature from March 18th to the 31st and the sum of mean daily temperature amplitudes from April 1st to the 14th, the grass pollen seasons were divided into five groups referring to the time of season start occurrence, whereby the early and moderate season starts were the most frequent in the studied period and they were especially related to mean daily temperature in the second half of March.

Heterogeneity in ragweed pollen exposure is determined by plant composition at small spatial scales

Pollen allergies are one of the most common health problems in the United States and over 20% of Americans are sensitized to the pollen produced by common ragweed (Ambrosia artemisiifolia L.). Despite the importance of allergenic pollen to public health, no research has linked land use and plant populations to spatial heterogeneity in airborne pollen concentrations. In order to quantify these relationships and elucidate the processes which lead to pollen exposure, we surveyed ragweed stem density in Detroit (Michigan, USA) as a function of land use. We then deployed 34 pollen collectors throughout the city and recorded ragweed cover in the immediate vicinity of each pollen collector. We found that ragweed populations were highest in vacant lots, a common land cover type in Detroit. Because ragweed population density was so strongly correlated to vacant lots, for which spatially explicit data were available, we were able to investigate whether observed ragweed pollen concentrations were a function of land use at the spatial scales of 10 m and 1 km. Both relationships were significant, and the combination of these two variables predicts a large portion of airborne ragweed pollen concentrations (R(2)=0.48). These results emphasize the important role of pollen production within the urban environment and show that management of allergenic pollen producing plants must be considered at multiple spatial scales. Our findings also demonstrate that there is too much spatial heterogeneity for a pollen collector at any given site to portray the allergenic pollen load experienced by different individuals within the same city. Finally, we discuss how spatial correlations between socio-economic status, vacant lots, and ragweed could help to explain the disproportionate amount of allergies and ragweed sensitization experienced by low income and minority populations in Detroit.

Ash pollen allergy: reliable detection of sensitization on the basis of IgE to Ole e 1

Background: Alongside hazel, alder and birch pollen allergies, ash pollen allergy is a relevant cause of hay fever during spring in the European region. For some considerable time, ash pollen allergy was not routinely investigated and its clinical relevance may well have been underestimated, particularly since ash and birch tree pollination times are largely the same. Ash pollen extracts are not yet well standardized and diagnosis is therefore sometimes unreliable. Olive pollen, on the other hand, is strongly cross-reactive with ash pollen and is apparently better standardized. Therefore, the main allergen of olive pollen, Ole e 1, has been postulated as a reliable alternative for the detection of ash pollen sensitization. Methods: To determine to what extent specific IgE against Ole e 1 in patients with ash pollen allergy is relevant, we included 183 subjects with ash pollen allergy displaying typical symptoms in March/April and positive skin prick test specific IgE against Ole e 1 (t224) and ash pollen (t25) and various birch allergens (Bet v 1, Bet v 2/v 4) in a retrospective study. Results: A significant correlation was seen between specific IgE against Ole e 1 and ash pollen, but also to a slightly lesser extent between IgE against Ole e 1 and skin prick test with ash pollen, the latter being even higher than IgE and skin prick test both with ash pollen. No relevant correlation was found with birch pollen allergens, demonstrating the very limited cross-reactivity between ash and birch pollen. Conclusion: It appears appropriate to determine specific IgE against Ole e 1 instead of IgE against ash pollen to detect persons with ash pollen allergy. Our findings may also support the idea of using possibly better standardized or more widely available olive pollen extracts instead of ash pollen extract for allergen-specific immunotherapy.

The effect of component-resolved diagnosis on specific immunotherapy prescription in children with hay fever

BACKGROUND

Sensitization to profilins and other cross-reacting molecules might hinder proper specific immunotherapy (SIT) prescription in polysensitized patients with pollen-related allergic rhinitis (AR). In these patients, component-resolved diagnosis (CRD) might modify SIT prescription by improving the identification of the disease-eliciting pollen sources.

OBJECTIVES

We sought to measure the effect of CRD on SIT prescription in children with pollen-related AR.

METHODS

Children (n = 651) with moderate-to-severe pollen-related AR were recruited between May 2009 and June 2011 in 16 Italian outpatient clinics. Skin prick test (SPT) reactivity to grass, cypress, olive, mugwort, pellitory, and/or Betulaceae pollen was considered clinically relevant if symptoms occurred during the corresponding peak pollen season. IgE sensitization to Phl p 1, Phl p 5, Bet v 1, Cup a 1, Art v 1, Ole e 1, Par j 2, and Phl p 12 (profilin) was measured by using ImmunoCAP. SIT prescription was modeled on SPT responses first and then remodeled considering also CRD according to GA(2)LEN-European Academy of Allergology and Clinical Immunology guidelines and the opinions of 14 pediatric allergists.

RESULTS

No IgE to the respective major allergens was detected in significant proportions of patients with supposed clinically relevant sensitization to mugwort (45/65 [69%]), Betulaceae (146/252 [60%]), pellitory (78/257 [30%]), olive (111/390 [28%]), cypress (28/184 [15%]), and grass (56/568 [10%]). IgE to profilins, polcalcins, or both could justify 173 (37%) of 464 of these SPT reactions. After CRD, the SPT-based decision on SIT prescription or composition was changed in 277 (42%) of 651 or 315 (48%) of 651 children according to the European or American approach, respectively, and in 305 (47%) of 651 children according to the opinion of the 14 local pediatric allergists.

CONCLUSIONS

In children with pollen-related AR, applying CRD leads to changes in a large proportion of SIT prescriptions as opposed to relying on clinical history and SPT alone. The hypothesis that CRD-guided prescription improves SIT efficacy deserves to be tested.

Objective approach for fending off the sublingual immunotherapy placebo effect in subjects with pollenosis: double-blinded, placebo-controlled trial

BACKGROUND

Symptom scoring for the assessment of allergen immunotherapy is associated with a substantial placebo effect.

OBJECTIVE

To assess the ability of exhaled breath temperature (EBT), a putative marker of airway inflammation, to evaluate objectively the efficacy of grass pollen sublingual immunotherapy in a proof-of-concept study.

METHODS

This was a double-blinded, placebo-controlled clinical trial in 56 subjects (mean ± SD 30 ± 12 years old, 33 men) sensitized to grass pollen. The objective measurements were EBT, spirometry, and periostin and high-sensitivity C-reactive protein in blood. Overall discomfort scored on a visual analog scale was used as a proxy for subjective symptoms. Evaluations were performed before, during, and after the grass pollen season.

RESULTS

Fifty-one subjects (25 and 26 in the active treatment and placebo groups, respectively) were assessed before and during the pollen season. The mean pre- vs in-season increase in EBT was significantly smaller (by 59.1%) in the active treatment than in the placebo group (P = .030). Of the other objective markers, only the blood periostin level increased significantly during the pollen season (P = .047), but without intergroup differences. Subjectively, the mean pre- vs in-season increase in the visual analog scale score was 32.3% smaller in the active treatment than in the placebo group, although this difference did not reach statistical significance (P = .116).

CONCLUSION

These results suggest that the efficacy of grass pollen sublingual immunotherapy can be assessed by EBT, a putative quantitative measurement of airway inflammation, which is superior in its power to discriminate between active and placebo treatment than a subjective assessment of symptoms assessed on a visual analog scale.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01785394.

Identification of potential sources of airborne Olea pollen in the Southwest Iberian Peninsula

This study aims to determine the potential origin of Olea pollen recorded in Badajoz in the Southwest of the Iberian Peninsula during 2009-2011. This was achieved using a combination of daily average and diurnal (hourly) airborne Olea pollen counts recorded at Badajoz (south-western Spain) and Évora (south-eastern Portugal), an inventory of olive groves in the studied area and air mass trajectory calculations computed using the HYSPLIT model. Examining olive pollen episodes at Badajoz that had distinctly different diurnal cycles in olive pollen in relation to the mean, allowed us to identify three different scenarios where olive pollen can be transported to the city from either distant or nearby sources during conditions with slow air mass movements. Back trajectory analysis showed that olive pollen can be transported to Badajoz from the West on prevailing winds, either directly or on slow moving air masses, and from high densities of olive groves situated to the Southeast (e.g. Andalucía). Regional scale transport of olive pollen can result in increased nighttime concentrations of this important aeroallergen. This could be particularly important in Mediterranean countries where people can be outdoors during this time due to climate and lifestyle. Such studies that examine sources and the atmospheric transport of pollen are valuable for allergy sufferers and health care professionals because the information can be incorporated into forecasts, the outputs of which are used for avoiding exposure to aeroallergens and planning medication. The results of studies of this nature can also be used for examining gene flow in this important agricultural crop.

Molecular biomarkers for grass pollen immunotherapy

Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.

A glossary for biometeorology

Here we present, for the first time, a glossary of biometeorological terms. The glossary aims to address the need for a reliable source of biometeorological definitions, thereby facilitating communication and mutual understanding in this rapidly expanding field. A total of 171 terms are defined, with reference to 234 citations. It is anticipated that the glossary will be revisited in coming years, updating terms and adding new terms, as appropriate. The glossary is intended to provide a useful resource to the biometeorology community, and to this end, readers are encouraged to contact the lead author to suggest additional terms for inclusion in later versions of the glossary as a result of new and emerging developments in the field.

Nitration of the birch pollen allergen Bet v 1.0101: efficiency and site-selectivity of liquid and gaseous nitrating agents

Nitration of the major birch pollen allergen Bet v 1 alters the immune responses toward this protein, but the underlying chemical mechanisms are not yet understood. Here we address the efficiency and site-selectivity of the nitration reaction of recombinant protein samples of Bet v 1.0101 with different nitrating agents relevant for laboratory investigations (tetranitromethane, TNM), for physiological processes (peroxynitrite, ONOO^–), and for the health effects of environmental pollutants (nitrogen dioxide and ozone, O₃/NO₂). We determined the total tyrosine nitration degrees (ND) and the NDs of individual tyrosine residues (ND_Y). High-performance liquid chromatography coupled to diode array detection and HPLC coupled to high-resolution mass spectrometry analysis of intact proteins, HPLC coupled to tandem mass spectrometry analysis of tryptic peptides, and amino acid analysis of hydrolyzed samples were performed. The preferred reaction sites were tyrosine residues at the following positions in the polypeptide chain: Y83 and Y81 for TNM, Y150 for ONOO^–, and Y83 and Y158 for O₃/NO₂. The tyrosine residues Y83 and Y81 are located in a hydrophobic cavity, while Y150 and Y158 are located in solvent-accessible and flexible structures of the C-terminal region. The heterogeneous reaction with O₃/NO₂ was found to be strongly dependent on the phase state of the protein. Nitration rates were about one order of magnitude higher for aqueous protein solutions (∼20% per day) than for protein filter samples (∼2% per day). Overall, our findings show that the kinetics and site-selectivity of nitration strongly depend on the nitrating agent and reaction conditions, which may also affect the biological function and adverse health effects of the nitrated protein.

Climate change and air pollution: Effects on pollen allergy and other allergic respiratory diseases

The observational evidence indicates that recent regional changes in climate, particularly temperature increases, have already affected a diverse set of physical and biological systems in many parts of the world. Allergens patterns are also changing in response to climate change and air pollution can modify the allergenic potential of pollen grains especially in the presence of specific weather conditions.

Although genetic factors are important in the development of asthma and allergic diseases, their rising trend can be explained only by changes occurring in the environment and urban air pollution by motor vehicles has been indicated as one of the major risk factors responsible for this increase.

Despite some differences in the air pollution profile and decreasing trends of some key air pollutants, air quality is an important concern for public health in the cities throughout the world.

Due to climate change, air pollution patterns are changing in several urbanized areas of the world with a significant effect on respiratory health. The underlying mechanisms of all these interactions are not well known yet. The consequences on health vary from decreases in lung function to allergic diseases, new onset of diseases, and exacerbation of chronic respiratory diseases. In addition, it is important to recall that an individual’s response to pollution exposure depends on the source and components of air pollution, as well as meteorological conditions. Indeed, some air pollution-related incidents with asthma aggravation do not depend only on the increased production of air pollution, but rather on atmospheric factors that favor the accumulation of air pollutants at ground level.

Associations between thunderstorms and asthma morbidity of pollinosis-affected people have also been identified in multiple locations around the world (Fig.1).

Cite this as D’Amato G, Bergmann KC, Cecchi L, Annesi-Maesano I, Sanduzzi A, Liccardi G, Vitale C, Stanziola A, D’Amato M. Climate change and air pollution — Effects on pollen allergy and other allergic respiratory diseases. Allergo J Int 2014; 23: 17–23 DOI 10.1007/s40629-014-0003-7

A factor clouding the problem is that laboratory evaluations do not reflect what happens during natural exposition.

Considering these aspects, governments worldwide, international organizations, and cooperations such as the World Health Organization (WHO) and the European Health Policy of the European Union (EU) are facing a growing problem of the respiratory effects induced by gaseous and particulate pollutants arising from motor vehicle emissions.

Chimeras of Bet v 1 and Api g 1 reveal heterogeneous IgE responses in patients with birch pollen allergy

BACKGROUND

Characterization of IgE-binding epitopes of allergens and determination of their patient-specific relevance is crucial for the diagnosis and treatment of allergy.

OBJECTIVE

We sought to assess the contribution of specific surface areas of the major birch pollen allergen Bet v 1.0101 to binding IgE of individual patients.

METHODS

Four distinct areas of Bet v 1 representing in total 81% of its surface were grafted onto the scaffold of its homolog, Api g 1.0101, to yield the chimeras Api-Bet-1 to Api-Bet-4. The chimeras were expressed in Escherichia coli and purified. IgE binding of 64 sera from Bet v 1-sensitized subjects with birch pollen allergy was determined by using direct ELISA. Specificity was assessed by means of inhibition ELISA.

RESULTS

rApi g 1.0101, Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4 bound IgE from 44%, 89%, 80%, 78%, and 48% of the patients, respectively. By comparing the amount of IgE binding to the chimeras and to rApi g 1.0101, 81%, 70%, 75%, and 45% of the patients showed significantly enhanced IgE binding to Api-Bet-1, Api-Bet-2, Api-Bet-3, and Api-Bet-4, respectively. The minority (8%) of the sera revealed enhanced IgE binding exclusively to a single chimera, whereas 31% showed increased IgE binding to all 4 chimeras compared with rApi g 1.0101. The chimeras inhibited up to 70% of IgE binding to rBet v 1.0101, confirming the specific IgE recognition of the grafted regions.

CONCLUSION

The Bet v 1-specific IgE response is polyclonal, and epitopes are spread across the entire Bet v 1 surface. Furthermore, the IgE recognition profile of Bet v 1 is highly patient specific.

Sustained efficacy and safety of a 300IR daily dose of a sublingual solution of birch pollen allergen extract in adults with allergic rhinoconjunctivitis: results of a double-blind, placebo-controlled study

Background

Allergic rhinoconjunctivitis (ARC) due to birch pollen is a growing health concern in Europe. Here, we report the efficacy and safety of 300IR birch pollen sublingual solution administered discontinuously for 2 consecutive years to patients with birch-associated allergic rhinoconjunctivitis.

Methods

Birch pollen-allergic adults were randomized in this double blind study to 300IR birch pollen sublingual solution or placebo, daily, starting 4 months before and continuing through the pollen season for two pollen seasons. Randomization was stratified according to the presence or absence of oral allergy syndrome (OAS). The primary efficacy endpoint was the Average Adjusted Symptom Score (AAdSS) over the second pollen season and was analyzed by ANCOVA. Secondary efficacy endpoints included the AAdSS over the first pollen period. Safety was evaluated by means of adverse event monitoring.

Results

574 patients (284 in the active group and 290 in the placebo group) were randomized and 496 completed the study. Over the second pollen period, the least square (LS) mean AAdSS was significantly lower in the 300IR group than in the placebo group (LS mean difference −2.04, 95% CI [−2.69, −1.40], (p <0.0001) with a relative reduction of 30.6%. Results were consistent in patients with and without OAS (−33.6% and −28.4%, respectively). A significant reduction in LS mean AAdSS was also observed over the first pollen season. The most frequently reported adverse events were application site reactions: oral pruritus, throat irritation, and mouth edema. There were no reports of anaphylaxis.

Conclusions

Pre- and co-seasonal treatment with 300IR birch pollen sublingual solution demonstrated sustained clinical efficacy over 2 pollen seasons and was well tolerated in adults with birch pollen-associated allergic rhinoconjunctivitis. Efficacy results were consistent in patients with and without oral allergy syndrome.

Trial registration

ClinicalTrials.gov: NCT01731249.

Characterization of protein expression of Platanus pollen following exposure to gaseous pollutants and vehicle exhaust particles

Being major ornamental street trees, species of Platanus are widely planted in the Shanghai urban area. A great deal of allergenic Platanus pollen is released from the trees and suspended in the atmosphere during its flowering season, ultimately causing allergic respiratory diseases. Few papers have focused on the distribution of this type of pollen and its expression of allergenic proteins. In order to investigate any differences in protein expression in Platanus pollen following exposure to gaseous and particulate pollutants, a special apparatus was designed. Exposure condition (such as temperature, humidity, and exposure time) of Platanus pollen and gaseous pollutants can be simulated using of this apparatus. Fresh Platanus orientalis pollen, pollutant gases (NO₂, SO₂, NH₃), and typical urban ambient particles (vehicle exhaust particles, VEPs) were mixed in this device to examine possible changes that might occur in ambient airborne urban pollen following exposure to such pollutants. Our results showed that the fresh P. orientalis pollen became swollen, and new kinds of particles could be found on the surface of the pollen grains after exposure to the pollutants. The results of SDS-PAGE showed that five protein bands with molecular weights of 17-19, 34, 61, 82, and 144 kDa, respectively, were detected and gray scale of these brands increased after the pollen exposure to gaseous pollutants. The two-dimensional gel electrophoresis analysis demonstrated that a Platanus pollen allergenic protein (Pla a1, with a molecular weight of 18 kDa) increased in abundance following exposure to pollutant gases and VEPs, implying that air pollutants may exacerbate the allergenicity of pollen.

In vitro exposure of Ostrya carpinifolia and Carpinus betulus pollen to atmospheric levels of CO, O3 and SO 2

Ostrya spp. and Carpinus spp. pollen was in vitro exposed to three atmospheric pollutants: CO, O3 and SO2. Two levels of each pollutant were used, and the first level corresponds to a concentration about the atmospheric hour-limit value acceptable for human health protection in Europe and the second level to about the triple of the first level. Experiments were done under artificial solar light with temperature and relative humidity controlled. The viability of the exposed pollen samples showed a significant decrease. Also, the germination percentage showed a significant decrease in both exposed pollens, and the effect was most pronounced for SO2, followed by O3 and CO. A general decreasing trend in the total soluble protein content of the exposed pollen samples when compared with the control was observed, but it was only statistically significant for the Ostrya spp pollen. The results showed marked effects were observed on the Ostrya spp. and Carpinus spp. pollen when exposed to air pollutant levels that can be considered safe for human health protection.

Environmental behaviour of airborne Amaranthaceae pollen in the southern part of the Iberian Peninsula, and its role in future climate scenarios

The Amaranthaceae family includes a number of species which, through a series of specific adaptations, thrive in salty soils, arid environments and altered human settlements. Their ability to tolerate high temperatures favours summer flowering, giving rise to the widespread involvement of Amaranthaceae pollen grains in summer allergies, both in Mediterranean Europe and in areas with arid climates. This study analysed a 21-year set of historical airborne Amaranthaceae pollen records for an area located in the southern part of the Iberian Peninsula, in order to chart species' environmental reaction to changing climate conditions which occurred in the last decades. Airborne pollen data were collected from January 1991 to December 2011 using a Hirst-type volumetric impact sampler. Results showed that Amaranthaceae pollen remained in the atmosphere for over 6 months along the year, from early spring until early autumn. The annual Pollen Index ranged from barely 200 grains to almost 2000 grains, and was strongly influenced by rainfall during the flowering period, which prompted the development of new individuals and thus an increase in pollen production. A trend was noted towards increasingly early pollen peak dates; peaks were recorded in August-September in years with summer rainfall, but as early as May-June in years when over 50% of annual rainfall was recorded in the months prior to flowering. The gradual decline in the annual Pollen Index over later years is attributable not only to growing urbanisation of the area but also to a change in rainfall distribution pattern. High maximum temperatures in spring were also directly related to the peak date and the Pollen Index. This ability to adapt to changeable and occasionally stressful and restrictive, environmental conditions places Amaranthaceae at a competitive advantage with respect to other species sharing the same ecological niche. An increased presence of Amaranthaceae is likely to have a greater impact on future scenarios for pollen allergy diseases associated with climate change.

Minimum prick test panel for adult patients with asthma and rhinitis in Ankara, Turkey

OBJECTIVE

Determination of the number and type of allergens needed to be tested in epidemiological studies is important in order to identify most of the sensitized subjects with a cost-effective approach. This study aimed to investigate the minimum skin prick test panel for the identification of at least 95% of the sensitized subjects with symptoms of asthma and/or allergic rhinitis (AR) in Ankara, Turkey.

METHODS

Skin prick test results of 7492 patients who were referred to our outpatient clinic with clinical symptoms of asthma and/or AR between 1991 and 2005 were evaluated retrospectively. Seven allergens were tested in all and 13 allergens in 4202 patients. The allergen group needed for detection of 95% of the sensitized subjects was determined for both the 7 and 13 allergen panels. The study protocol was approved by the local ethics committee of Hacettepe University.

RESULTS

The atopy prevalences in the whole study population and in 4202 patients tested with the 13 allergen panel were calculated as 32.2% and 42.6%, respectively. Three allergens (Phleum pratense, Dermatophagoides pteronyssinus and Artemisia vulgaris) within the 7 allergen panel were adequate for the identification of at least 95% of the sensitized subjects. Olea europae was added to the previous three allergens when the 13 allergen panel was applied.

CONCLUSION

Three to four allergens are sufficient for identification at least 95% of sensitized subjects with asthma and/or AR in Ankara, Turkey.

Trace elements in the pollen of Ambrosia artemisiifolia: what is the effect of soil concentrations?

Concentrations of nine trace elements (Ba, Cd, Cr, Cu, Mn, Ni, Pb, Tl and Zn) were measured in a plant bearing allergenic pollens (ragweed) and their transfers from soils to the roots and then to the pollens were investigated. The soil, roots and pollens collected from flowers were sampled at 26 urban sites. Soil pH, soil organic carbon and total-recoverable trace elements (TE) in soil, roots and pollens were measured. The three biogeochemical compartments are well discriminated according to their TE concentrations. The concentrations (in μg g(-1)) in pollens decreased as follow: Zn (59.5-205)>Mn (19.4-117)>Ba≈Cr≈Cu≈Ni≈Pb (0.54-27.7)>Cd (0.06-0.77)>>Tl (0.0015-0.0180). Mean elemental allocation within ragweed always favored roots over pollen but, at site level, inverse pattern is also observed mostly for Zn and slightly for Cu and Ni. Significant predictive models of TE concentrations in pollens were obtained using soil or root properties only for Cd, Ni and Pb. They all involved positive relationships between TE concentrations in pollens and in soil or roots. Estimates of short-term exposure of human to TE carried out by ragweed pollens indicate TE absorption of less than 50 ng, far below thresholds of air quality criteria. Investigating the TE chemistry of pollens is a required first step to validate the impact of TE in pollens on human health and on the prevalence and intensity of allergy symptoms and atopic diseases.

Variability of Corylus avellana, L. CorA and profilin pollen allergens expression

Corylus avellana is the source of inhalant allergies induced by hazel pollen as well as food allergies induced after ingestion of hazelnuts. In this study, real-time PCR approach was used to analyse expression of hazel pollen allergens on the molecular level. Relative quantity of hazelnut allergens Corylus avellana, L. CorA and Corylus avellana, L. pollen profiling in samples from different Ukraine areas were determining and comparing. Differences among the levels of both analysed allergen transcripts were found for hazel CorA and profillin. In both cases, the expression within the urbanized growth conditions was higher when compared to the sample from village area. The average expression for CorA was 0.84 times higher than for profilin and the results are very variable depending on the place of growth. Expression levels here were within the range of 2.957 up to the 52.936. Profilin expression was the highest in the sample from the polluted place of growth-cement plant area with the value of 52 times higher when compared to the sample from the village area. In this study, comparison of expression levels of hazel CorA and profiling pollen allergens was performed for the first time. Real-time PCR assay developed in this study proved the sensitivity for detection of the changes of the hazel pollen allergens expression levels and could benefit labs by fast and reproducible detection method of these allergens.

Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber

Monoecious species provide a comprehensive system to study the developmental programs underlying the establishment of female and male organs in unisexual flowers. However, molecular resources for most monoecious non-model species are limited, hampering our ability to study the molecular mechanisms involved in flower development of these species. The objective of this study was to identify differentially expressed genes during the development of male and female flowers of the monoecious species Quercus suber, an economically important Mediterranean tree. Total RNA was extracted from different developmental stages of Q. suber flowers. Non-normalized cDNA libraries of male and female flowers were generated using 454 pyrosequencing technology producing a total of 962,172 high-quality reads with an average length of 264 nucleotides. The assembly of the reads resulted in 14,488 contigs for female libraries and 10,438 contigs for male libraries. Comparative analysis of the transcriptomes revealed genes differentially expressed in early and late stages of development of female and male flowers, some of which have been shown to be involved in pollen development, in ovule formation and in flower development of other species with a monoecious, dioecious, or hermaphroditic sexual system. Moreover, we found differentially expressed genes that have not yet been characterized and others that have not been previously shown to be implicated in flower development. This transcriptomic analysis constitutes a major step toward the characterization of the molecular mechanisms involved in flower development in a monoecious tree with a potential contribution toward the knowledge of conserved developmental mechanisms in other species.

[Prevalence of sensitisation to aeraoallergens and food allergens: results of the German Health Interview and Examination Survey for Adults (DEGS1)]

In view of the increasing prevalence of allergies, up-to-date data on the prevalence of allergic sensitisation are of major interest. In the German Health Interview and Examination Survey for Adults (DEGS1) (2008-2011) blood samples from a population-based sample of 7,025 participants aged 18 to 79 years were analysed for specific IgE antibodies against 50 common single allergens and screened for common aeroallergens (SX1) and grass pollen (GX1). In all, 48.6 % of the participants were sensitised to at least one allergen. Overall, men were more frequently sensitised to at least one allergen than women were. Sensitisations to at least one allergen were more common among younger than older participants and among participants with a higher socio-economic status. In all, 33.6 % of the participants were sensitised to common aeroallergens, 25.5  % to food allergens and 22.6 % to wasp or bee venoms. Compared with the German National Health Interview and Examination Survey 1998 (GNHIES98), the prevalence of sensitisation to common aeroallergens increased from 29.8 to 33.6 %.This increase was statistically significant only in women. The results of DEGS1 still showed a high prevalence of allergic sensitisation. An English full-text version of this article is available at SpringerLink as supplemental.

Pollen-induced allergic rhinitis in 1360 Italian children: comorbidities and determinants of severity

BACKGROUND

Pollen-induced allergic rhinoconjunctivitis (AR) is highly prevalent and rapidly evolving during childhood. General practitioners may not be fully aware of the nature and severity of symptoms experienced by patients and might underestimate the prevalence of moderate or severe disease. Thus, the relevance of early diagnosis and intervention may be overlooked.

OBJECTIVES

To investigate the severity of pollen-induced AR and its determinants in Italian children referred to allergy specialists and who had never received specific immunotherapy (SIT).

METHODS

Children (age 4-18 yr) affected by pollen-induced AR who had never undergone SIT were recruited between May 2009 and June 2011 in 16 pediatric outpatient clinics in 14 Italian cities. Recruited children's parents answered standardized questionnaires on atopic diseases (International Study of Allergy and Asthma in Childhood, Allergic Rhinitis and its Impact on Asthma, Global Initiative for Asthma). The children underwent skin-prick test (SPT) with several airborne allergens and six food allergens. Information on socio-demographic factors, parental history of allergic diseases, education, perinatal events, breastfeeding, nutrition and environmental exposure in early life was collected through an informatics platform shared by the whole network of clinical centers (AllergyCARD™).

RESULTS

Among the 1360 recruited patients (68% males, age 10.5 ± 3.4 yr), 695 (51%) had moderate-to-severe AR, 533 (39%) asthma, and 325 (23.9%) oral allergy syndrome (OAS). Reported onset of pollen-induced AR was on average at 5.3 ± 2.8 yr, and its mean duration from onset was 5.2 ± 3.3 yr. Only 6.2% of the patients were pollen-monosensitized, and 84.9% were sensitized to ≥3 pollens. A longer AR duration was significantly associated with moderate-to-severe AR symptoms (p 0.004), asthma (p 0.030), and OAS comorbidities (p < 0.001).

CONCLUSIONS

This nationwide study may raise awareness of the severity of pollen-induced AR among Italian children who have never received pollen SIT. The strong association between pollen-induced AR duration and several markers of disease severity needs replication in longitudinal studies, while suggesting that countrywide initiatives for earlier diagnosis and intervention should be planned.

Can spatial data substitute temporal data in phenological modelling? A survey using birch flowering

In addition to the evaluation of long-term series, the analysis of spatial gradients, such as urbanization gradients, may be helpful in assessing phenological responses to global warming. But are phenological responses of birch (Betula pendula Roth) assessed by temperature variations comparable over time and space and can spatially calibrated models predict long-term phenological data adequately? We calibrated and tested linear regression models and the process-based DORMPHOT model on phenological and temperature data sampled along an urbanization gradient in 2010 and 2011 in the German cities Munich and Ingolstadt (spatial data). Additionally, we analysed data from the German Meteorological Service for the period 1991-2010 (long-term data). The model comparison showed that the DORMPHOT model performed better than the linear model. Therefore, the importance of forcing and chilling sums as well as photoperiod, factors which were all considered in the DORMPHOT model, was evident. Models calibrated on spatial data produced good predictions of spatial data, but they were less adequate for predicting long-term data. Therefore, a time-for-space substitution might not always be appropriate. This finding was also confirmed by a comparison of temperature response rates. The rate of change in the spatial data (-4.4 days °C(-1)) did not match the changes observed in the long-term data (-1.9 days °C(-1)). Consequently, it is important not to generalize results derived from one specific study method, but their inherent methodological, spatial and temporal peculiarities have to be considered.

Effects of airborne birch pollen levels on clinical symptoms of seasonal allergic rhinoconjunctivitis

BACKGROUND

Most panel studies focusing on rhinitis and conjunctivitis symptoms and birch pollen have been performed on a linear basis and have not included air pollution and meteorological variables as potential confounders. The objective of this panel study was to assess the relationship between symptoms of seasonal allergic rhinoconjunctivitis and daily airborne birch pollen concentrations, checking with adequate statistical tools the shapes of concentration-response curves and controlling for confounders.

METHODS

The severity of rhinitis, conjunctivitis, and bronchial symptoms was recorded daily in March and April 2010 (3,311 person-days) in 61 seasonal allergic rhinoconjunctivitis patients sensitized to birch. Data were analyzed with generalized additive and generalized estimating equation models to quantify the effects of birch pollens.

RESULTS

The relationship between birch pollen and the percentage of patients with nasal, ocular and bronchial symptoms was linear until birch daily average concentrations of, respectively, 110, 70, and 70 grains/m(3); it reached a plateau thereafter. For an increase of 10 grains/m(3), the OR (95% CI) for nasal, ocular, and bronchial symptoms were, respectively, 1.07 (1.03-1.12), 1.17 (1.08-1.27), and 1.12 (1.03-1.21). At the beginning of the season, no nasal or ocular symptoms were observed below a threshold of 30 grains/m(3).

CONCLUSIONS

Adequate modeling regression shows that the clinical response to natural exposure to birch pollen in sensitized patients varies during Betula pollen season, with a threshold at the beginning of the season, while over the whole season the relationship is linear for nasal, ocular, and bronchial symptoms up to a saturation point, followed by a plateau.

Peanut sensitization profiles in Italian children and adolescents with specific IgE to peanuts

Peanuts are one of the most relevant foods implicated in IgE-mediated adverse reactions in pediatric population. This study aimed to evaluate the pattern of sensitization towards five peanut allergenic components (rAra h 1, 2, 3, 8 and 9) in a population of Italian children and adolescents with specific IgE (sIgE) to peanut. rAra h 9 was the main allergen implicated in peanut sensitization (58%), followed by rAra h 8 (35%), rAra h 2 (27%), rAra h 3 (23%) and rAra h 1 (12.5%). rAra h 1, 2, and 3 were the main allergenic components in young children: 8/13 (62%) between 2 and 5 years, 8/23 (35%) between 6 and 11 years, and 3/12 (25%) between 1 and 16 years. No differences were found among the levels of sIgE towards rAra h 1, 2, 3, and 9 in the three groups; in contrast, the levels of sIgE against rAra h 8 showed an increasing trend according to age. In conclusion rAra h 1, 2, and 3 were the prevalent sensitizing allergens during the first years of life in Italian patients with sIgE to peanuts ("genuine" allergy); in contrast rAra h 9 and 8 were mainly involved in school-age children and adolescents with pollen allergy ("secondary" sensitization).

[Birch pollen allergy]

In the North-East of France, birch is the main tree responsible of spring pollen allergy. However, the epidemiology of sensitization to birch pollen remains unclear. Monosensitization to birch pollen seems rare because of the frequency of cross-reactions with other pollens of the same botanical family via the major allergen Bet v 1. Around one third of patients with allergic rhinoconjunctivitis due to birch pollen are also asthmatics and a half suffer from a food allergy, essentially an oral syndrome due to rosaceae fruits eaten raw. The molecular allergens of birch pollen are well-known and have been cloned. They are available for use in in vitro diagnostic tests and also in clinical trials of specific immunotherapy.

IPHEN--a real-time network for phenological monitoring and modelling in Italy

This paper aims to describe the Italian PHEnology Network (IPHEN), a cooperative project started in 2006 with the aim of producing nationwide maps of analysis and forecast of plants phenological stages mainly used to satisfy the needs of agriculture, health and environmental care. Iphen is a data processing system composed of the following main segments (a) collection of atmospheric and phenological data, (b) processing of data with suitable phenological and geo-statistical models and (c) phenological maps of analysis and forecast. In more detail, IPHEN maps of analysis (featuring phenological stages reached at the date of processing) are produced with models based on a Normal Heat Hours approach which weighs hourly air temperature effectiveness for plant phenological progression applied to national grids of hourly temperature derived from the operational agro-meteorological network of CRA-CMA. A correction scheme based on phenological surveys provided by volunteer observers is applied to the first guess maps of analysis to obtain final maps. Forecast maps (prediction of the days of occurrence of relevant phenological stages) are produced on the basis of GFS model medium range forecasts and climatic data. Freeware IPHEN maps for grapevine, common and Arizona cypress, black elder, olive and locust trees are broadcasted weekly on the CRA-CMA website. The positive operational results of IPHEN are testified by 150 maps broadcasted during the 2011 season for the above-mentioned species. The system performances and reliability have been analysed focusing on the analysis of phenological simulation errors and on the sensitivity of phenological maps to anomalous atmospheric circulation patterns. The error analysis shows that phenological models are characterized by advances/delays that justify the adoption of an observation based correction scheme. The sensitivity analysis highlights that the system is responsive to the effects of circulation blocking systems leading to phenological advances and delays.

Eosinophilic airway inflammation and airway hyperresponsiveness according to aeroallergen sensitization pattern in patients with lower airway symptoms

Purpose

Sensitization to specific allergens may be important in the development of allergic airway inflammation and airway hyperresponsiveness (AHR). We evaluated the effect of specific aeroallergen sensitization on eosinophilic airway inflammation and AHR.

Methods

We reviewed retrospectively the clinical data of subjects who underwent skin prick tests to aeroallergens, induced sputum analysis, and methacholine bronchial provocation tests to evaluate lower airway symptoms as well as analyzed the associations between the pattern of aeroallergen sensitization and sputum eosinophilia or AHR.

Results

Of the 1,202 subjects be enrolled, 534 (44.4%) were sensitized to at least one aeroallergen in skin tests. AHR was demonstrated in 23.5% and sputum eosinophilia in 38.8%. Sputum eosinophilia was significantly associated with sensitization to perennial allergens (OR, 1.9; 95% CI, 1.4-2.5), house dust mite (OR, 1.7; 95% CI, 1.3-2.3), dog (OR, 1.9; 95% CI, 1.1-3.3), and cat (OR, 2.1; 95% CI, 1.4-3.4). AHR was associated with sensitization to perennial allergens (OR, 2.7; 95% CI, 2.0-3.7), house dust mite (OR, 2.2; 95% CI, 1.6 3.2), Alternaria (OR, 2.3; 95% CI, 1.2-4.7), and cat (OR, 2.7; 95% CI, 1.7-4.3). Sensitization to more perennial allergens increased the risk for sputum eosinophilia and AHR. There was no relationship with individual seasonal allergens.

Conclusion

The development of airway eosinophilic inflammation and AHR in an adult Korean population was associated with sensitization to perennial allergens rather than seasonal allergens.

Cloning, expression in E. coli and immunological characterization of Par j 3.0201, a Parietaria pollen profilin variant

Parietaria judaica pollen is one of the main sources of allergens in the Mediterranean area. Its allergenic composition has been studied in detail showing the presence of two major allergens (Par j 1 and Par j 2) and two minor allergens belonging to the profilin and calcium binding protein families of allergens (Par j 3 and Par j 4, respectively). Clinical reports support the hypothesis of a limited cross-reactivity between profilin from Parietaria and unrelated sources. We screened a P. judaica cDNA library to identify novel forms of profilins with allergenic activity. This strategy allowed us to isolate a 767 bp cDNA containing the information for a 131 amino acids protein with homology to profilins from unrelated sources greater than that observed with the already published Parietaria profilins. This profilin was expressed in Escherichia coli as a recombinant protein and its immunological prevalence was studied in a population of Parietaria allergic patients from Southern Europe. Immunoblotting analysis showed that the Parietaria profilin was recognized by IgE from 6.5% of the allergic population. Finally, a selected population of profilin allergic patients was enrolled to demonstrate the cross-reactivity of this novel variant with other profilins from grass and date palm. In conclusion, molecular cloning and immunological studies have allowed the isolation, expression and immunological characterization of a novel cross-reactive profilin allergen from P. judaica pollen named Par j 3.0201.

Pla a_1 aeroallergen immunodetection related to the airborne Platanus pollen content

Platanus hispanica pollen is considered an important source of aeroallergens in many Southern European cities. This tree is frequently used in urban green spaces as ornamental specie. The flowering period is greatly influenced by the meteorological conditions, which directly affect its allergenic load in the atmosphere. The purpose of this study is to develop equations to predict the Platanus allergy risk periods as a function of the airborne pollen, the allergen concentration and the main meteorological parameters. The study was conducted by means two volumetric pollen samplers; a Lanzoni VPPS 2000 for the Platanus pollen sampling and a Burkard multivial Cyclone Sampler to collect the aeroallergen particles (Pla a_1). In addiction the Dot-Blot and the Raman spectroscopy methods were used to corroborate the results. The Pla a_1 protein is recorded in the atmosphere after the presence of the Platanus pollen, which extend the Platanus pollen allergy risk periods. The Platanus pollen and the Pla a 1 allergens concentration are associated with statistical significant variations of some meteorological variables: in a positive way with the mean and maximum temperature whereas the sign of the correlation coefficient is negative with the relative humidity. The lineal regression equation elaborated in order to forecast the Platanus pollen content in the air explain the 64.5% of variance of the pollen presence in the environment, whereas the lineal regression equation elaborated in order to forecast the aeroallergen a 54.1% of the Pla a_1 presence variance. The combination of pollen count and the allergen quantification must be assessed in the epidemiologic study of allergic respiratory diseases to prevent the allergy risk periods.

The influence of sensitisation to pollens and moulds on seasonal variations in asthma attacks

No large study has described the seasonal variation in asthma attacks in population-based asthmatics in whom sensitisation to allergen has been measured. 2,637 young adults with asthma living in 15 countries reported the months in which they usually had attacks of asthma and had skin-prick tests performed. Differences in seasonal patterns by sensitisation status were assessed using generalised estimating equations. Most young adults with asthma reported periods of the year when their asthma attacks were more common (range: 47% in Sweden to 86% in Spain). Seasonal variation in asthma was not modified by sensitisation to house dust mite or cat allergens. Asthmatics sensitised to grass, birch and Alternaria allergens had different seasonal patterns to those not sensitised to each allergen, with some geographical variation. In southern Europe, those sensitised to grass allergens were more likely to report attacks occurred in spring or summer than in winter (OR March/April 2.60, 95% CI 1.70-3.97; OR May/June 4.43, 95% CI 2.34-8.39) and smaller later peaks were observed in northern Europe (OR May/June 1.25, 95% CI 0.60-2.64; OR July/August 1.66, 95% CI 0.89-3.10). Asthmatics reporting hay fever but who were not sensitised to grass showed no seasonal variations. Seasonal variations in asthma attacks in young adults are common and are different depending on sensitisation to outdoor, but not indoor, allergens.

A molecular diagnostic algorithm to guide pollen immunotherapy in southern Europe: towards component-resolved management of allergic diseases

Correct identification of the culprit allergen is an essential part of diagnosis and treatment in immunoglobulin E (IgE)-mediated allergic diseases. In recent years, molecular biology has made important advances facilitating such identification and overcoming some of the drawbacks of natural allergen extracts, which consist of mixtures of various proteins that may be allergenic or not, specific for the allergen source or widely distributed (panallergens). New technologies offer the opportunity for a more accurate component-resolved diagnosis, of benefit especially to polysensitized allergic patients. The basic elements of molecular diagnostics with potential relevance to immunotherapy prescription are reviewed here, with a focus on Southern European sensitization patterns to pollen allergens. We propose a basic algorithm regarding component-resolved diagnostic work-up for pollen allergen-specific immunotherapy candidates in Southern Europe; this and similar algorithms can form the basis of improved patient management, conceptually a 'Component-Resolved Allergy Management'.

Year clustering analysis for modelling olive flowering phenology

It is now widely accepted that weather conditions occurring several months prior to the onset of flowering have a major influence on various aspects of olive reproductive phenology, including flowering intensity. Given the variable characteristics of the Mediterranean climate, we analyse its influence on the registered variations in olive flowering intensity in southern Spain, and relate them to previous climatic parameters using a year-clustering approach, as a first step towards an olive flowering phenology model adapted to different year categories. Phenological data from Cordoba province (Southern Spain) for a 30-year period (1982-2011) were analysed. Meteorological and phenological data were first subjected to both hierarchical and "K-means" clustering analysis, which yielded four year-categories. For this classification purpose, three different models were tested: (1) discriminant analysis; (2) decision-tree analysis; and (3) neural network analysis. Comparison of the results showed that the neural-networks model was the most effective, classifying four different year categories with clearly distinct weather features. Flowering-intensity models were constructed for each year category using the partial least squares regression method. These category-specific models proved to be more effective than general models. They are better suited to the variability of the Mediterranean climate, due to the different response of plants to the same environmental stimuli depending on the previous weather conditions in any given year. The present detailed analysis of the influence of weather patterns of different years on olive phenology will help us to understand the short-term effects of climate change on olive crop in the Mediterranean area that is highly affected by it.

First annual register of allergenic pollen in Talca, Chile

BACKGROUND

There are no data on atmospheric pollen in Talca. In the present work, our aim is to describe the amount of pollen grain in the atmosphere of the city of Talca likely to cause pollinosis of its inhabitants.

METHODS

A volumetric Hirst sampler (Burkard seven-day recording device) was used to study pollen levels. It was placed in the centre of Talca from May 2007 to April 2008.

RESULTS

The highest airborne presence of pollen, as measured in weekly averages, was Platanus acerifolia with a maximum weekly daily average of 203 grains/m³ registered during September and October. The second highest was Acer pseudoplatanus with a maximum weekly daily average of 116 grains/m³. Populus spp. had a maximum weekly daily average 103 grains/m³. Olea europaea reached 19 grains/m³ in November. Grasses presented high levels of pollen counts with a maximum weekly daily average of 27 grains/m³ from the end of August until the end of January. Pollens of Plantago spp. Rumex acetosella and Chenopodium spp. had a similar distribution and were present from October to April with maximum weekly daily average of 7 grains/m³, 7 grains/m³ and 3 grains/m³ respectively. Significant concentrations of Ambrosia artemisiifolia were detected from February until April.

CONCLUSION

The population of Talca was exposed to high concentrations of allergenic pollen, such as P. acerifolia, A. pseudoplatanus, and grasses in the months of August through November. The detection of O. europaea and A. artemisiifolia is important as these are emergent pollens in the city of Talca. Aerobiological monitoring will provide the community with reliable information about the level of allergenic pollens, improving treatment and quality of life of patients with respiratory allergy.

Allergens of weed pollen: an overview on recombinant and natural molecules

Weeds represent a botanically unrelated group of plants that usually lack commercial or aesthetical value. Pollen of allergenic weeds are able to trigger type I reactions in allergic patients and can be found in the plant families of Asteraceae, Amaranthaceae, Plantaginaceae, Urticaceae, and Euphorbiaceae. To date, 34 weed pollen allergens are listed in the IUIS allergen nomenclature database, which were physicochemically and immunologically characterized to varying degrees. Relevant allergens of weeds belong to the pectate lyase family, defensin-like family, Ole e 1-like family, non-specific lipid transfer protein 1 family and the pan-allergens profilin and polcalcins. This review provides an overview on weed pollen allergens primarily focusing on the molecular level. In particular, the characteristics and properties of purified recombinant allergens and hypoallergenic derivatives are described and their potential use in diagnosis and therapy of weed pollen allergy is discussed.

Allergenic potential of rice-pollen proteins: expression, immuno-cross reactivity and IgE-binding

Pollen proteins from several grass species have been identified and characterized as causative allergens in grass pollinosis. In contrast, allergenic potential of pollen proteins from rice, which belongs to the same Poaceae family, has not well been investigated, despite that a few clinical cases have been reported on rice-pollen allergy. In this study, to characterize expression and allergenic potential of pollen proteins from rice (Oryza sativa, ssp. japonica), rice putative proteins for β-expansin (EXP), a Ca(2+)-binding protein (CBP)/polcalcin, extensin (EXT), profilin (PRF) and polygalacturonase (PGA) retrieved from a rice complete cDNA database were prepared as recombinant proteins, and the antibodies to these recombinant proteins were obtained. Immuno-blotting and immuno-histological analyses showed that rice putative EXP, EXT and PGA were expressed abundantly in anther tissue and pollen granules and immuno-cross reactive with pollen proteins from timothy grass. ELISA and immuno-dot blotting analyses using serum specimens from allergic patients showed that majority of the specimens was positive in the IgE-binding to EXP and EXT, but weakly to PGA and almost negative to PRF. EXP and EXT were suggested to be potentially allergenic in the rice-pollen allergy as well as the grass pollinosis.

Molecular and immunological characterization of ragweed (Ambrosia artemisiifolia L.) pollen after exposure of the plants to elevated ozone over a whole growing season

Climate change and air pollution, including ozone is known to affect plants and might also influence the ragweed pollen, known to carry strong allergens. We compared the transcriptome of ragweed pollen produced under ambient and elevated ozone by 454-sequencing. An enzyme-linked immunosorbent assay (ELISA) was carried out for the major ragweed allergen Amb a 1. Pollen surface was examined by scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and phenolics were analysed by high-performance liquid chromatography. Elevated ozone had no influence on the pollen size, shape, surface structure or amount of phenolics. ATR-FTIR indicated increased pectin-like material in the exine. Transcriptomic analyses showed changes in expressed-sequence tags (ESTs), including allergens. However, ELISA indicated no significantly increased amounts of Amb a 1 under elevated ozone concentrations. The data highlight a direct influence of ozone on the exine components and transcript level of allergens. As the total protein amount of Amb a 1 was not altered, a direct correlation to an increased risk to human health could not be derived. Additional, the 454-sequencing contributes to the identification of stress-related transcripts in mature pollen that could be grouped into distinct gene ontology terms.

Streamer discharge reduces pollen-induced inflammatory responses and injury in human airway epithelial cells

Although epidemiological studies have demonstrated that cedar pollen influences respiratory health, effective method for inactivating cedar pollen has not been established. Streamer discharge is a type of plasma discharge in which high-speed electrons collide with oxygen and nitrogen molecules. It reportedly has the ability to eliminate bacteria, mould, chemical substances and allergens. The present study investigated the influence of pollen on BEAS-2B cell line, derived from human airway epithelial cells, as well as the efficiency of streamer discharge on pollen-induced health effects. Airway epithelial cells were exposed to non-treated pollen and streamer-discharged pollen at doses of 100 and 1000 μg/mL for 6 or 24 h. Non-treated pollen at a dose of 1000 μg/mL significantly decreased cell viability and induced both mRNA and protein expression of interleukin-6, whereas streamer-discharged pollen showed the attenuated changes as compared with non-treated pollen. Further, scanning electron micrographs showed that streamer discharge caused the fine structural changes of pollen. These results provide the first experimental evidence that pollen at a high dose affects cell viability and inflammatory responses, and streamer discharge technology attenuates their influences by decomposing pollen.