Allergy in the Mediterranean area. III: Cross reactivity among Oleaceae pollens

TFOS Lifestyle Report: Impact of environmental conditions on the ocular surface

Environmental risk factors that have an impact on the ocular surface were reviewed and associations with age and sex, race/ethnicity, geographical area, seasonality, prevalence and possible interactions between risk factors are reviewed. Environmental factors can be (a) climate-related: temperature, humidity, wind speed, altitude, dew point, ultraviolet light, and allergen or (b) outdoor and indoor pollution: gases, particulate matter, and other sources of airborne pollutants. Temperature affects ocular surface homeostasis directly and indirectly, precipitating ocular surface diseases and/or symptoms, including trachoma. Humidity is negatively associated with dry eye disease. There is little data on wind speed and dewpoint. High altitude and ultraviolet light exposure are associated with pterygium, ocular surface degenerations and neoplastic disease. Pollution is associated with dry eye disease and conjunctivitis. Primary Sjögren syndrome is associated with exposure to chemical solvents. Living within a potential zone of active volcanic eruption is associated with eye irritation. Indoor pollution, "sick" building or house can also be associated with eye irritation. Most ocular surface conditions are multifactorial, and several environmental factors may contribute to specific diseases. A systematic review was conducted to answer the following research question: "What are the associations between outdoor environment pollution and signs or symptoms of dry eye disease in humans?" Dry eye disease is associated with air pollution (from NO2) and soil pollution (from chromium), but not from air pollution from CO or PM10. Future research should adequately account for confounders, follow up over time, and report results separately for ocular surface findings, including signs and symptoms.

Pollen respiratory allergy: Is it really seasonal?

Allergic rhinitis (AR) is a highly prevalent respiratory condition that carries a heavy burden and can have a significant impact on patient quality of life. AR is caused by seasonal or perennial exposure to outdoor pollens and molds as well as indoor allergic triggers. In this review article, we discuss the factors associated with the development of AR throughout the year and the fact that patients with AR need continuous treatment rather than seasonal treatment. Conventionally, AR has been mainly categorized into seasonal AR and perennial AR, but these classes do not seem to be well-adapted. Climate changes, temperature changes, and high carbon dioxide (CO₂) concentration affect the growth of plants and increase the length of pollen seasons and pollen allergenicity. Air pollution aggravates allergic sensitization symptoms in AR sensitized individuals. Due to increased air pollution and indefinite pollen seasons AR symptoms are present throughout the year. Patients with AR often need continuous treatment, which should be considered while making the strategy for treating allergic rhinitis sufferers. Management of AR involves avoiding the allergen, medications for symptomatic relief, anti-inflammatory therapies, and allergy immunotherapy. Although the first-generation H₁-antihistamines reduce AR symptoms, they cause sedation and impair cognitive functions; thus, second-generation antihistamines (ie, levocetirizine, loratadine, bilastine, fexofenadine) are preferred. The efficacy and safety of fexofenadine for the treatment of seasonal allergic rhinitis (SAR) symptoms have been demonstrated by numerous clinical studies, irrespective of the season and underlying allergen. In this review, we discuss the allergic rhinitis classification, the role of climate change, air pollution, and factors contributing to year-round symptoms in patients with AR and the need for continuous pharmacological treatment for management.

Assessing cross-reactivity in allergen immunotherapy

Knowledge of patterns of pollen cross-reactivity is crucial for formulation of immunotherapy vaccines. As phylogenetic relationships have become better clarified through the use of tools such as gene sequencing, it is apparent that cross-reactivity reflects taxonomy in the vast majority of cases. Contradictory observations of unexpected cross-reactivity between distantly related plants require explanation. There are many proteins, presumably performing vital functions, tightly preserved throughout the evolutionary tree from plants to animals. Examples are profilins, lipid transfer proteins, and pathogenesis-related proteins. These may function as panallergens. The small differences that exist between these ubiquitous proteins may explain why these are frequently minor allergens, not reacting in the majority of allergic sera. This article summarizes cross-reactivity from older studies using crude pollen extracts as well as newer research of purified or recombinant allergenic proteins. The patterns of cross-allergenicity that emerge should be helpful in guiding therapeutic decisions.

Peptide Glycodendrimers as Potential Vaccines for Olive Pollen Allergy

Olive pollen is one of the most important causes of respiratory allergy, with Ole e 1 being the most clinically relevant sensitizing allergen. Peptide-based vaccines represent promising therapeutic approaches, but the use of adjuvants is required to strengthen the weak immunogenicity of small peptides. We propose the use of dendrimeric scaffolds conjugated to the T cell immunodominant epitope of Ole e 1 (OE_109-130) for the development of novel vaccines against olive pollen allergy. Four dendrimeric scaffolds containing an ester/ether with nine mannoses, an ester succinimidyl linker with nine N-acetyl-glucosamine units or nine ethylene glycol units conjugated to OE_109-130 peptide were designed, and their cytotoxicity, internalization pattern, and immunomodulatory properties were analyzed in vitro. None of the dendrimers exhibited cytotoxicity in humanized rat basophil (RBL-2H3), human bronchial epithelial Calu-3, and human mast LAD2 cell lines. Confocal images indicated that mannosylated glycodendropeptides exhibited lower colocalization with a lysosomal marker. Moreover, mannosylated glycodendropeptides showed higher transport tendency through the epithelial barrier formed by Calu-3 cells cultured at the air-liquid interface. Finally, mannosylated glycodendropeptides promoted Treg and IL10⁺Treg proliferation and IL-10 secretion by peripheral blood mononuclear cells from allergic patients. Mannosylated dendrimers conjugated with OE_109-130 peptide from Ole e 1 have been identified as suitable candidates for the development of novel vaccines of olive pollen allergy.

Extraction and quantification of Ole e 1 from atmospheric air samples: An optimized protocol

Olive pollen is the main cause of pollinosis in Mediterranean countries. The immunological analysis of Ole e 1, the major allergen of Olea europaea, has usually carried out by means of ELISA (Enzyme-Linked ImmunoSorbent Assay). However, most published works only specify the methodology related to antigen quantifications, but not the related to protein extraction. Furthermore, the results obtained are not compared with different buffers or modifications of them. The main aim of this study is to obtain an optimized and reproducible ELISA protocol for quantifications of Ole e 1 in the atmosphere. The study of Ole e 1 allergen and olive pollen in the atmosphere of Malaga (Spain) was carried out by means of an automatic multi-vial cyclonic sampler and a Hirst volumetric pollen trap, respectively. ELISA was tuned up on the basis of previously published protocols to quantify this allergen. Variations in the concentrations of capture and detection antibodies, as well as in the buffers used to carry out the extraction, were evaluated. The highest protein extraction was obtained when a modified buffer was applied. The correlation analysis between daily pollen concentrations and allergen quantifications showed highly significant values. The ELISA protocol, together with the buffer combination proposed in this work, considerably reduced the concentrations of capture and detection antibodies used for quantifying Ole e 1 in the atmosphere, allowing detect this allergen even in days in which the airborne pollen concentration was very low or null.

Annual and intradiurnal variation of dominant airborne pollen and the effects of meteorological factors in Çeşme (Izmir, Turkey)

In this present study, airborne pollen in Çeşme was investigated between February 17, 2012 and February 17, 2014 using the volumetric method. Çeşme, one of Turkey's most important tourism centers, which attracts numerous local and foreign tourists each year, is a district of Izmir, a province in the western part of Turkey. During the 2-year study, 12,905 pollen grains belonging to 64 taxa (33 arboreal, 31 non-arboreal plants) were detected. However, the 2-year data results revealed that the taxa with the pollen concentration more than 4% in the atmosphere were Cupressaceae/Taxaceae (4268 pollen, 33.07%), Olea europaea (1614 pollen grains, 12.51%), Pinaceae (1085 pollen grains, 8.41%), Quercus spp. (1081 pollen grains, 8.38%), Pistacia spp. (743 pollen grains, 5.76%), and Poaceae (557 pollen grains, 4.32%), all of which comprised 72.44% of the total count. The relationship between the daily pollen counts belonging to these six taxa and the hourly average temperature (°C), daily precipitation (mm), relative humidity (%), and wind speed (km/h) was assessed using the Spearman correlation test, and significant results were determined. During the study, the intradiurnal distribution of the aforementioned pollen varied. The highest pollen concentration was detected between 11:00 a.m. and 6:00 p.m. (first year 30.3%; second year 30.1%).

Antibacterial activities of medicinal plants used in Mexican traditional medicine

ETHNOPHARMACOLOGICAL RELEVANCE

We provide an extensive summary of the in vitro antibacterial properties of medicinal plants popularly used in Mexico to treat infections, and we discuss the ethnomedical information that has been published for these species.

MATERIALS AND METHODS

We carried out a bibliographic investigation by analyzing local and international peer-reviewed papers selected by consulting internationally accepted scientific databases from 1995 to 2014. We provide specific information about the evaluated plant parts, the type of extracts, the tested bacterial strains, and the inhibitory concentrations for each one of the species. We recorded the ethnomedical information for the active species, as well as their popular names and local distribution. Information about the plant compounds that has been identified is included in the manuscript. This review also incorporates an extensive summary of the available toxicological reports on the recorded species, as well as the worldwide registries of plant patents used for treating bacterial infections. In addition, we provide a list with the top plant species with antibacterial activities in this review RESULTS: We documented the in vitro antibacterial activities of 343 plant species pertaining to 92 botanical families against 72 bacterial species, focusing particularly on Staphylococcus aureus, Mycobacterium tuberculosis, Escherichia coli and Pseudomonas aeruginosa. The plant families Asteraceae, Fabaceae, Lamiaceae and Euphorbiaceae included the largest number of active species. Information related to popular uses reveals that the majority of the plants, in addition to treating infections, are used to treat other conditions. The distribution of Mexican plants extended from those that were reported to grow in just one state to those that grow in all 32 Mexican states. From 75 plant species, 225 compounds were identified. Out of the total plant species, only 140 (40.57%) had at least one report about their toxic effects. From 1994 to July 2014 a total of 11,836 worldwide antibacterial patents prepared from different sources were recorded; only 36 antibacterial patents from plants were registered over the same time period. We offered some insights on the most important findings regarding the antibacterial effects, current state of the art, and research perspectives of top plant species with antibacterial activities in vitro.

CONCLUSIONS

Studies of the antibacterial in vitro activity of medicinal plants popularly used in Mexico to treat infections indicate that both the selection of plant material and the investigation methodologies vary. Standardized experimental procedures as well as in vivo pharmacokinetic studies to document the effectiveness of plant extracts and compounds are necessary. This review presents extensive information about the medicinal plants possessing antibacterial activity that has been scientifically studied and are popularly used in Mexico. We anticipate that this review will be of use for future studies because it constitutes a valuable information tool for selecting the most significant plants and their potential antibacterial properties.

Exploratory study of tolerability and immunological effect of a short up-dosing immunotherapy phase with a standardised allergen extract derived from pollen of Olea europaea

BACKGROUND

A new subcutaneous specific immunotherapy (SCIT) product adsorbed on aluminium hydroxide has been developed with a short and simplified up-dosing phase, containing a biologically standardized allergen pollen extract from Olea europaea.

OBJECTIVE

To assess the tolerability profile of the updosing phase and its immunological effect, in terms of specific IgG4 and IgE levels and immediate skin reactivity.

MATERIAL AND METHODS

The study was an exploratory, multi-centre, open-label, single-arm, phase II/III clinical trial. Adults with a clinical history of allergic rhinoconjunctivitis with/without asthma due to sensitization to olive pollen were selected. Five up-dosing doses (300, 600, 3000, 6000 and 15000SQ+) were administered at weekly intervals, followed by a maintenance dose (15000SQ+) after 2 weeks. Adverse events were collected during the 30 min observation period after injections, after a telephone contact 2 days after each visit, and after reviewing the subjects' diary. IgG4 and IgE levels and immediate skin reactivity were evaluated at the beginning and at the end of the trial.

RESULTS

Ninety-three subjects were included in the trial (mean age, 35.7 ± 10.3 years; women, 66.7 %). A total of 95 adverse drug reactions, all mild in intensity and non-serious, were reported during the trial: 85 local in 34.4 % subjects, 9 systemic in 4.3 % subjects and one non-specific (grade 0). Within 6 weeks, significant changes in IgG4 and IgE levels and in immediate skin reactivity to Olea europaea were accomplished.

CONCLUSION

This new SCIT derived from pollen of Olea europaea presented a good tolerability profile and induced significant immunological responses already after a 6 week treatment. However, the non-controlled design may limit the interpretation of these results.

TRIAL REGISTRATION

EudraCT no: 2011-004852-20; ClinicalTrials.gov Identifier: NCT01674595.

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.

Geographical variation in the prevalence of sensitization to common aeroallergens in adults: the GA(2) LEN survey

BACKGROUND

Geographical variation in the prevalence of sensitization to aeroallergens may reflect differences in exposure to risk factors such as having older siblings, being raised on a farm or other unidentified exposures.

OBJECTIVE

We wanted to measure geographical variation in skin prick test positivity and assess whether it was explained by differences in family size and/or farm exposure. We also compared prevalence in younger and older subjects.

METHODS

Within the Global Allergy and Asthma European Network (GA(2) LEN) survey, we measured the prevalence of skin prick positivity to a panel of allergens, and geometric mean serum total immunoglobulin E (IgE), in 3451 participants aged 18-75 years in 13 areas of Europe. Estimated prevalence was standardized to account for study design. We compared prevalence estimates in younger and older subjects and further adjusted for age, gender, smoking history, farm exposure, number of older siblings and body mass index (BMI).

RESULTS

Skin prick test positivity to any one of the measured allergens varied within Europe from 31.4% to 52.9%. Prevalence of sensitization to single allergens also varied. Variation in serum total IgE was less marked. Younger participants had higher skin prick sensitivity prevalence, but not total IgE, than older participants. Geographical variation remained even after adjustment for confounders.

CONCLUSION

Geographical variation in the prevalence of skin prick test positivity in Europe is unlikely to be explained by geographical variation in gender, age, smoking history, farm exposure, family size and BMI. Higher prevalence in younger, compared to older, adults may reflect cohort-associated increases in sensitization or the influence of ageing on immune or tissue responses.

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.

Analysis of olive allergens

Olive pollen is one of the most important causes of seasonal respiratory allergy in Mediterranean countries, where this tree is intensely cultivated. Besides this, some cases of contact dermatitis and food allergy to the olive fruit and olive oil have been also described. Several scientific studies dealing with olive allergens has been reported, being the information available about them constantly increasing. Up to date, twelve allergens have been identified in olive pollen while just one allergen has been identified in olive fruit. This review article describes considerations about allergen extraction and production, also describing the different methodologies employed in the physicochemical and immunological characterization of olive allergens. Finally, a revision of the most relevant studies in the analysis of both olive pollen and olive fruit allergens is carried out.

Evaluation of ash pollen sensitization pattern using proteomic approach with individual sera from allergic patients

BACKGROUND

In Europe, sensitization to ash pollen induces pollinosis with cross-reactivities with other pollen sources. The aim of the study was to identify the repertoire of ash pollen allergens and evaluate the extent of the diversity of the IgE response in ash allergic patients.

METHODS

The IgE reactivities of 114 ash pollen- and eight grass pollen-sensitized patients were screened by 1D immunoblot (SDS-PAGE) against ash pollen extract. The IgE reactivities of 13 ash pollen- and two grass pollen-sensitized patients were then evaluated in 2D immunoblots. Some IgE- and non-IgE-reactive proteins were identified by mass spectrometry.

RESULTS

In 1D analysis, 86% of sera showed binding to Fra e 1 (18-20 kDa), 23% to Fra e 2 (14 kDa), 3% to Fra e 3 (10 kDa) and 57% to High Molecular Weight allergens (HMW, >30 kDa). Individual analysis of 2D immunoblots showed several IgE-binding protein areas among which three were more often recognized: (i) Fra e 1 comprising, at least, 15 isoforms, (ii) a series of acidic spots (45 kDa), and (iii) Fra e 2, the ash profilin. HMW allergens could be resolved in four areas; two unidentified, one homologous to beta-galactosidase and the other to sugar transport proteins. A malate deshydrogenase and calmodulin were shown to be IgE-binding proteins and 10 non-IgE reactive proteins were identified.

CONCLUSIONS

No direct correlation was evidenced between IgE profile and the degree of sensitization even though 2 spectrotypes could be distinguished. Our data contribute to a better delineation of ash pollen allergens and patterns of sensitization.

GA(2)LEN skin test study I: GA(2)LEN harmonization of skin prick testing: novel sensitization patterns for inhalant allergens in Europe

BACKGROUND

Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe. It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe.

AIMS

The Global Asthma and Allergy European Network (GA(2)LEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study is the first approach to implement a standardized procedure for skin prick testing in allergies against inhalant allergens with a standardized pan-European allergen panel.

METHODS

The study population consisted of patients who were referred to one of the 17 participating centres in 14 European countries (n = 3034, median age = 33 years). Skin prick testing and evaluation was performed with the same 18 allergens in a standardized procedure across all centres.

RESULTS

The study clearly shows that many allergens previously regarded as untypical for some regions in Europe have been underestimated. This could partly be related to changes in mobility of patients, vegetation or climate in Europe.

CONCLUSION

The results of this large pan-European study demonstrate for the first time sensitization patterns for different inhalant allergens in patients across Europe. The standardized skin prick test with the standardized allergen battery should be recommended for clinical use and research. Further EU-wide monitoring of sensitization patterns is urgently needed.

Skin prick test reactivity in allergic rhinitis patients to airborne pollens

The aim was to investigate the impact of atmospheric pollen in determining allergic rhinitis. It was conducted with 130 patients with allergic rhinitis in three different sites in Eskisehir, Turkey, in 2000-2001, using a gravimetric method with a Durham sampler. Skin prick test results, the symptoms of patients and their findings all confirmed the presence of allergic reactions to pollen allergens in the patients observed. During the period, a total of 47,082 pollen grains/cm(2) belonging to 45 taxa were recorded. Of the total pollen grains, 81.0% were arboreal and 18% non-arboreal. The majority of the investigated pollen grains were from Pinaceae, Salix spp., Chenopodiaceae/Amaranthaceae, Cupressaceae and Poaceae. Pollen concentrations reached the highest level in May (54.36%). The pollen allergens provoking severe sensitization were grasscereal mixtures (58.5%), followed by arboreals (33.8%). All patients (100.0%) were sensitive to grass. This study emphasizes the significance of determining the types and concentrations of pollen with a view to comparing changes in highly concentrated allergens.

Concentrations of airborne pollen grains in Sivrihisar (Eskisehir), Turkey

Pollen grains in the atmosphere of Sivrihisar were studied for a continuous period of 2 years (1 January 2005-31 December 2006) using a Durham sampler. During this period, pollen grains belonging to 41 taxa were recorded, 24 of which belonged to arboreal plants and 17 to non-arboreal. From these, 23,219 were identified in 2005 and 34,154 in 2006. Of the total pollen grains, 90.46% were arboreal, 9.43% non-arboreal, and 0.1% unidentifiable. The majority of the investigated allergic pollen grains were from Pinaceae, Cupressaceae, Fraxinus spp., Cedrus spp., Artemisia spp., Poaceae, Chenopodiaceae/Amaranthaceae, Populus spp., Quercus spp., Urticaceae and Asteraceae, respectively. Pollen concentrations reached their highest levels in May. This information was then established into a calendar form according to the pollens determined in 2005-2006, in terms of annual, monthly and weekly numbers of taxa fall per cm2. A comparison between the results and the meteorological factors revealed a close relationship between pollen concentrations in the air and meteorological conditions. An increase in pollination was also linked to increasing temperatures and the wind. It was therefore concluded that high temperatures and relative humidity were also effective in increasing the number of pollens in the air.

Geographical variation in the prevalence of positive skin tests to environmental aeroallergens in the European Community Respiratory Health Survey I

BACKGROUND

Many studies have reported the prevalence of sensitization using skin prick tests. However, comparisons between studies and between regions are difficult because the number and the type of allergens tested vary widely. Using the European Community Health Respiratory Survey I data, the geographical variation of sensitization to environmental allergen as measured by skin tests was established.

METHODS

Adults aged 20-44 years, living in 35 centres in 15 developed countries, underwent skin tests for allergy to nine common aeroallergens: Dermatophagoides pteronyssinus, timothy grass, cat, Cladosporium herbarium, Alternaria alternata, birch, Olea europea, common ragweed and Parietaria judaica. The age-sex standardized prevalence of sensitization was determined and centres with high (95% confidence interval above and excluding study median) and low prevalence (95% confidence interval below and excluding study median) of sensitization to each allergen and to any of the nine allergens were identified.

RESULTS

There was substantial geographical variation in the prevalence of sensitization to each of the nine allergens tested and in the prevalence of sensitization to any allergen (lowest 17.1%, median 36.8% and highest 54.8%). Sensitization to D. pteronyssinus, grass pollen and cat were usually the most prevalent (median between centre 21.7%, 16.9% and 8.8%, respectively). Timothy grass sensitization was higher than that for any other pollen species.

CONCLUSIONS

As expected, geographical variations of sensitization to environmental allergen were observed across centres. These findings were compatible for those observed with serum-specific IgE. Skin tests can be used to assess the geographical distribution of allergens in a multicentric epidemiological survey.

Detection of airborne allergen (Ole e 1) in relation to Olea europaea pollen in S Spain

BACKGROUND

In recent years, it has been demonstrated that the air carries not only airborne pollen but also plant particles of smaller size that have allergenic activity, and, being within the respirable range, these particles can trigger rapid attacks in the lower respiratory tract. The study of particles according to size (0.7-40 micro m) could provide valuable information on the real allergenic activity in the atmosphere.

OBJECTIVE

The purpose of this study was to analyse the dynamics of airborne Olea europaea pollen in contrast to the allergenic activity of Ole e 1 in the atmosphere.

METHODS

The analyses were carried out with a Hirst-type volumetric collector and a cascade impactor simultaneously during the MPS of the olive. The indirect ELISA was used to detect the allergenic activity. The sampling was performed in Granada city centre (S Spain), in the Science Faculty building on the University of Granada from 30 April to 26 June 2005.

RESULTS AND CONCLUSIONS

This research demonstrates that both the allergenic activity as well as the pollen particles follow in a similar curve, except in periods before or succeeding the main Olea pollen season. The study of the distribution of the allergenic particles according to their sizes reveals that the highest concentrations are between 3.3 and <0.7 micro m, thus indicating that allergenic activity primarily involves paucimicronic particles.

Standardization of an Ash (Fraxinus excelsior) Pollen Allergen Extract

BACKGROUND

Ash tree (Fraxinus excelsior) is the main representative of the Oleaceae family in temperate zones. Diagnosis of ash pollen allergy is made difficult due to (1) an overlapping pollinization period with Betulaceae, (2) non-inclusion in current diagnostic assays, and (3) some cross- reactivity with minor allergens from Betulaceae. The aim of this study was to calibrate an ash pollen in-house reference preparation (IHRP) in allergic patients in order to produce standardized products for diagnosis and immunotherapy purposes.

METHODS

Ash pollen IHRP was extracted, ultrafiltered and freeze dried. Allergens in the extract were detected after 2-dimensional PAGE using specific sera and a monoclonal antibody. The Fra e 1 content of IHRP was evaluated by quantitative immunoprint. Forty-eight subjects from the North-East of France exhibiting clinical symptoms, a positive skin test and specific IgE levels > or =class 2 to ash pollen were recruited. IgE immunoprints were performed to select patients sensitized to the ash Fra e 1 allergen as opposed to cross-reacting allergens. Serial 10-fold dilutions of the IHRP were tested by skin prick tests in order to determine the concentration inducing a geometrical mean wheal diameter of 7 mm, said to correspond to an index of reactivity (IR) of 100 per millilitre.

RESULTS

IgE-reactive molecules in IHRP comprise Fra e 1, Fra e 2, a 9-kDa molecule (presumably Fra e 3), as well as a doublet at 15 kDa and high molecular weight allergens. The 100 IR concentration of IHRP inducing a geometrical mean wheal diameter of 7 mm in 22 patients sensitized to Fra e 1 corresponds to the 1/126 (w/v) extraction ratio (i.e. 259 microg/ml of protein by Bradford) and contains 17 microg/ml of Fra e 1. The variability in total activity of 5 batches of standardized extracts was found to be significantly reduced when compared with 7 non-standardized extracts.

CONCLUSION

An ash pollen IHRP was defined and molecularly characterized. Its successful standardization at 100 IR/ml in patients specifically sensitized to Fra e 1 allowed a skin reactivity-based calibration in properly diagnosed patients. Such a standardized ash pollen extract is a reliable tool to support immunotherapy of ash pollen allergy.

The major allergen of olive pollen Ole e 1 is a diagnostic marker for sensitization to Oleaceae

BACKGROUND

Trees of the family Oleaceae are important allergen sources, with a strongly varying geographic distribution. For example, olive pollen is an important allergen source in Mediterranean countries, whereas ash pollen dominates in Northern and Central Europe and North America. The aim of this study was to compare the profiles of olive and ash pollen allergens and to study the degree of cross-reactivity using populations of allergic patients selectively exposed to olive or ash pollen.

METHODS

Olive and ash pollen extracts were analyzed by IgE immunoblotting using sera from Spanish patients highly exposed to olive pollen and Austrian patients without olive but ash pollen exposure. IgE cross-reactivity was studied by qualitative immunoblot inhibition assays and semiquantitative ELISA inhibitions using olive, ash, birch, mugwort, timothy grass pollen extracts and the major olive pollen allergen, Ole e 1.

RESULTS

Spanish and Austrian patients exhibited an almost identical IgE-binding profile to olive and ash pollen allergens, with major reactivity directed against Ole e 1, and its homologous ash counterpart, Fra e 1. IgE inhibition experiments demonstrated extensive cross-reactivity between olive and ash pollen allergens. However, whereas cross-reactions between profilins and calcium-binding allergens also occurred between unrelated plant species, cross-reactivity to Ole e 1 was confined to plants belonging to the Oleaceae.

CONCLUSIONS

Ole e 1 is a marker allergen for the diagnosis of olive and ash pollen allergy.

A comparative analysis of the cross-reactivity in the polcalcin family including Syr v 3, a new member from lilac pollen

BACKGROUND

Polcalcins are pollen-specific allergens with two EF-hand calcium-binding sites that exhibit strong cross-reactivity. Our objective was to isolate and express the cDNA coding of the EF-hand calcium-binding allergen from lilac pollen and to study cross-reactivity with other polcalcins from related and nonrelated pollen sources with different specific antibodies and sera from two different populations.

METHODS

Specific cDNA was amplified by PCR, cloned and expressed in Escherichia coli. Purification was achieved by gel permeation and ion exchange chromatographies. ELISA titration and inhibition assays were performed using the recombinant forms of Syr v 3, Ole e 3, Che a 3 and Phl p 7 with sera from two Spanish regions with different sensitization profiles, as well as Phl p 7- and Ole e 3-specific polyclonal rabbit antisera, and an Ole e 3-specific monoclonal antibody.

RESULTS

Syr v 3 displays two EF-hand consensus sites and 8863 Da of theoretical molecular mass. The allergen consists of 80 residues with identities ranging from 66 to 87% with polcalcins included in this study. Syr v 3, Ole e 3, Che a 3 and Phl p 7 showed a similar IgG- and IgE-binding capacity although differences at quantitative level were observed depending on the population of patients' sera.

CONCLUSION

Syr v 3 is a polcalcin with structural and antigenic similarities to the members of this family. Diagnosis of polcalcin-sensitized patients could be performed whatever polcalcin used, whereas for immunotherapy, primary sensitization to a particular allergenic source should be considered.

Seasonal rhinitis, clinical characteristics and risk factors for asthma

BACKGROUND

The aim was to determine the clinical characteristics of patients with seasonal rhinitis (SR) and to disclose differences in the treatment of SR between an adult allergy clinic and other clinics over time.

METHODS

A retrospective study was conducted based on clinical records of 774 out of 955 patients diagnosed with SR in an adult allergy clinic between 1 January 1991 and 31 December 2003.

RESULTS

The mean age of the patients was 29.1 +/- 9.29 years and 62.7% were female. The most common major complaints of the patients were nasal symptoms in 82.3%. The mean duration of the disease was 6.76 +/- 6.8 years. The patients were symptomatic with a mean of 3.5 +/- 1.7 months a year, mostly during the period between April and July. Skin prick tests were positive in 685 patients (90.3%), where the most common sensitivity was against timothy grass (85.1%). The most common accompanying allergic diseases were food hypersensitivity in 14%, bronchial asthma in 13.4%, and drug allergy and/or intolerance in 9.6%. Although the use of specific immunotherapy and short-acting sedative antihistamines decreased over time, the use of nasal steroids and long-acting nonsedative antihistamines tended to increase before admission to our clinic. Older age (OR: 1.77, 95% CI: 1.06-2.94), presence of familial atopy (OR: 1.72, 95% CI: 1.04-2.85), respiratory symptoms (OR: 2.10, 95% CI: 1.75-2.50), ocular symptoms (OR: 0.77, 95% CI: 0.61-0.98) and metal allergy (OR: 0.25, 95% CI: 0.07-0.89) were associated with the development of asthma in patients with SR.

CONCLUSION

SR lasts approximately 3.5 months and the main cause in Ankara, Turkey is grass pollen sensitivity. Patients with any other allergic conditions make up 39.8% of the patients. SR patients are referred to allergy clinics quite late, which might be due to SR not being considered as a serious disease.

Cloning, expression, and clinical significance of the major allergen from ash pollen, Fra e 1

BACKGROUND

Ash tree, an Oleaceae member, is considered an important source of pollen allergy in Central Europe. Fra e 1 is a protein of the Ole e 1-like family, which regulates pollen tube growth. It has been suggested to be a relevant allergen from ash pollen.

OBJECTIVE

Cloning Fra e 1-cDNA and overproducing a properly folded recombinant allergen to analyze its clinical significance.

METHODS

Fra e 1-encoding cDNA was amplified by PCR, cloned in Escherichia coli , and sequenced. The recombinant allergen was produced in Pichia pastoris and used in immunoblotting, ELISA, histamine release, and skin prick tests. Sera and blood cells from patients sensitized to ash pollen as well as anti-Ole e 1 monoclonal and polyclonal antisera were used.

RESULTS

Recombinant Fra e 1 (rFra e 1) is a glycoprotein of 145 amino acids exhibiting 82%, 88%, and 91% identity with Syr v 1, Ole e 1, and Lig v 1, allergens of the Oleaceae family. It was secreted to the extracellular medium of the yeast cultures and purified by means of 3 chromatographic steps. IgG from Ole e 1-specific antibodies recognized rFra e 1. IgE antibodies from ash-sensitized patients bound to rFra e 1 with a prevalence of 75%. The recombinant allergen induced histamine release. Twenty-nine of 30 ash-sensitized patients were positive to rFra e 1 by skin prick tests.

CONCLUSION

Fra e 1 is a relevant allergen in ash pollen sensitization. It has been efficiently produced in P pastoris and could be used in diagnosis.

Food hypersensitivity in patients with seasonal rhinitis in Ankara

BACKGROUND

Food hypersensitivity (FH) affects 1-2 % of the adult population and is more common in atopic individuals. The aim of this study was to determine the frequency of FH and risk factors for its development in patients with seasonal rhinitis (SR) in our allergy clinic.

METHODS

We performed a retrospective study based on the medical records of 774 patients out of 955 patients diagnosed with SR in an adult allergy clinic between 1 January 1991 and 31 December 2003.

RESULTS

The mean age of the patients was 29.1 +/- 9.29 and 62.7 % were females. The most common major complaints were due to nasal symptoms in 82.3 %. The mean duration of SR was 6.8 +/- 6.8 years. Patients were symptomatic for a mean of 3.5 +/- 1.7 months per year. Skin prick tests (SPT) with common aeroallergens were positive in 685 patients (90.3 %), and the most common sensitivity was against timothy (85.1 %). The most common accompanying allergic disease was FH in 14 %. FH according to history and the results of SPT performed with food allergens were discordant. The most common clinical manifestations of FH were oral allergy (49.1 %) and cutaneous symptoms (38.9 %). Risk factors for the development of FH in patients with SR were dermatological symptoms, rhinitis duration > 5 years, symptom duration > 3 months per year, SPT reactivity to Artemisia vulgaris, tree pollen allergens (Corylus avellena, Betula verrucosa), and bee allergy.

CONCLUSION

FH was the most common (14 %) accompanying allergic disease in patients with SR. SPT with food allergens have limited diagnostic value for food allergy and/or intolerance. Risk factors for developing FH in patients with SR in Turkey were dermatological symptoms, duration of rhinitis > 5 years, duration of rhinitis symptoms > 3 months per year, and SPT reactivity to Corylus avellena.

Cross-reactivity of pollen allergens

Pollen cross-allergenicity has practical implications on the management of inhalant allergy, in both evaluation and therapy, especially with allergen vaccine immunotherapy. The study of cross-reactivity among pollen allergens has expanded beyond investigation of crude extracts to the characterization and cloning of numerous pollen proteins. In this review, the interrelationships between these pollen allergens in the context of botanical systematics are examined, to provide a framework for cross-reactivity understanding. Recommendations for choices in evaluation and therapy are given.

Ole e 1, the major allergen from olive (Olea europaea L.) pollen, increases its expression and is released to the culture medium during in vitro germination

Ole e 1 is a well-characterized allergenic protein from olive pollen. This paper examines its presence and that of its transcripts during in vitro pollen germination and pollen tube growth. A significant increase of the protein was detected after the emergence of the pollen tube, whereas part of the protein was released into the culture medium throughout pollen germination. A slight increase in the number of Ole e 1 transcripts was also detected prior to the described rise in the protein level. Within the pollen tube, the allergen was localized in the subapical region, mainly in the lumen of endoplasmic reticulum cisternae. Ole e 1 was also localized extracellularly in the vicinity of the pollen tube cell wall. These findings are discussed regarding the biological role attributed to the protein during pollen hydration and pollen tube growth and in terms of their importance for the understanding of the allergenic response in humans. On the basis of recent findings for the LAT52 protein in tomato, we propose that the homologous Ole e 1 protein might participate in a similar signal transduction pathway in olive, to control pregermination and pollen tube emergence and guidance.

A Major Allergen from Pollen Defines a Novel Family of Plant Proteins and Shows Intra- and Interspecie Cross-Reactivity

Olive tree (Olea europaea) pollen is a main cause of allergy associated with extensive areas of Europe and North America. Ole e 10, a small (10.8 kDa) and acidic (pI 5.8) protein, has been identified as a major allergen from the olive pollen, isolated, and characterized. Circular dichroism analysis gave 17% alpha helix, 33% beta sheet, and 21% beta turn for its secondary structure. Based on amino acid sequences of tryptic peptides, the protein was cloned and sequenced. The allergen consists of a single polypeptide chain of 102 aa, with a signal peptide of 21 residues. Ole e 10 showed homology with the C-terminal domain of another olive allergen, Ole e 9 (1,3-beta-glucanase, 53% identity), with deduced sequences from Arabidopsis thaliana genes (42-46% identity) and with polypeptide segments (Cys boxes) of proteins involved in yeast development (Epd1/Gas-1p/Phr2 families; 42-43% similarity). Ole e 10 showed 55% prevalence for olive-allergic patients and exhibited an IgE response dependent on its conformation. Remarkable IgE cross-reactivity was detected with Ole e 9, but no correlation was observed between the individual IgE responses to both allergens. Ole e 10 shares IgE B cell epitopes with proteins from Oleaceae, Gramineae, Betulaceae, Chenopodiaceae, Cupressaceae, Ambrosia, and Parietaria pollens, latex, and vegetable foods, such as tomato, kiwi, potato, and peach. These data indicate that Ole e 10 is a new pan-allergenic plant protein that shows notable intra- and interspecie IgE cross-reactivity and is a powerful candidate to be involved in pollen-latex-fruit syndrome.

Key pollen allergens in North America

OBJECTIVE

To discuss major pollen aeroallergens in North America that are essential for effective immunotherapy and to propose a list of pollen aeroallergens that could be prioritized for allergen standardization.

DATA SOURCES

PubMed was used to search the existing medical literature. No date restrictions were used. Keywords included allergy, aeroallergen, taxonomy, cross-reactivity, pollen, and specific genus and species names.

RESULTS

Tree species possess relatively unique allergens, and representative members should be chosen at the genus or family level. In the Composite family, there is significant cross-reactivity between ragweed species within the Ambrosia genus. Selection of one species should be sufficient for skin testing and immunotherapy. Extensive allergenic cross-reactivity exists among grasses. Selection of timothy grass alone or in combination with a single northern grass species provides adequate coverage in the northeastern regions of North America.

CONCLUSIONS

One of the goals within the field of allergy should be to identify high-priority targets for future development of standardized commercial extracts. The standardization of increasing numbers of allergen extracts potentially benefits the discipline of allergy by facilitating transfer of care among physician practices, improving uniformity of patient care, and providing a template on which geographically specific extract choices can be built.

Patterns of pollen cross-allergenicity

Knowledge of patterns of pollen cross-reactivity is crucial for diagnostics and especially for formulation of immunotherapy vaccines in times of diminishing availability of pollen extract constituents. As phylogenetic relationships have become better clarified, it becomes apparent that cross-reactivity does reflect taxonomy in the very great majority of cases. Contradictory observations of unexpected cross-reactivity between unrelated plants, sometimes remarkably distant ones, require explanation. There are many proteins, presumably performing vital functions, that are tightly preserved throughout the evolutionary tree from plants to animals, such as profilins, lipid transfer proteins, and pathogenesis-related proteins. These might function as panallergens. The small differences that exist between these ubiquitous proteins explain why these are frequently minor allergens not reacting in the majority of allergic sera. This review summarizes cross-reactivity studies with both crude pollen extracts and purified or recombinant allergenic proteins. The patterns of cross-allergenicity that emerge should be helpful in guiding both diagnostic and therapeutic decisions.

Monoclonal antibody-based method for measuring olive pollen major allergen Ole e 1

BACKGROUND

Olive tree pollen is an important cause of inhalant allergy in Mediterranean countries. The major allergen of this pollen, Ole e 1, has caused reactions in the sera of >80% of olive-sensitive patients. Accurate standardization of allergenic products for diagnosis and immunotherapy is essential to guarantee their quality, and measurement of the major allergen content is becoming an important aspect of standardization procedures.

OBJECTIVE

To develop a two-site enzyme-linked immunoadsorbent assay (ELISA) for the quantification of Ole e 1.

METHODS

BALB/c mice were immunized with purified natural Ole e 1. After fusion and screening by direct ELISA, one of the monoclonal antibodies (5A3) was selected as the capture antibody in an ELISA for Ole e 1 quantification. Bound allergens were detected by a combination of biotinylated Ole e 1-specific polyclonal rabbit antibody and peroxidase-conjugated streptavidin. This ELISA was subsequently evaluated and compared with other techniques.

RESULTS

The developed ELISA was highly reproducible and sensitive, with a detection limit of 0.5 ng/mL and a practical range of 1 to 10 ng/mL. The Ole e 1 content ranged from 3 to 50% of the total protein among the nine Olea europaea pollen extracts studied. The assay also detected Ole e 1-like proteins in pollen from other Oleaceae. Correlation was good between the Ole e 1 content determined by ELISA and scanning densitometry and the immunoglobulin E-binding activity of the extracts.

CONCLUSION

The described Ole e 1 ELISA is sensitive, reproducible, specific, and reliable, and therefore, can be helpful for standardization of olive pollen extracts intended for clinical use.

The allergen profile of ash (Fraxinus excelsior) pollen: cross-reactivity with allergens from various plant species

BACKGROUND

Ash, a wind-pollinated tree belonging to the family Oleaceae, is distributed world-wide and has been suggested as a potent allergen source in spring time.

OBJECTIVE

The aim of this study was to determine the profile of allergen components in ash pollen in order to refine diagnosis and therapy for patients with sensitivity to ash pollen

METHODS

The IgE reactivity profile of 40 ash pollen-allergic patients was determined by immunoblotting. Antibodies raised to purified pollen allergens from tree and grass pollens were used to identify cross-reactive structures in ash pollen extract. IgE immunoblot inhibition studies were performed with recombinant and natural pollen allergens to characterize ash pollen allergens and to determine the degree of cross-reactivity between pollen allergens from ash, olive, birch, grasses and weeds.

RESULTS

The allergen profile of ash pollen comprises Fra e 1, a major allergen related to the major olive allergen, Ole e 1, and to group 11 grass pollen allergens, the panallergen profilin, a two EF-hand calcium-binding protein, a pectinesterase-like molecule and an allergen sharing epitopes with group 4 grass pollen allergens. Thus, the relevant allergens of ash are primarily allergens that share epitopes with pollen allergens from other tree, grass and weed species.

CONCLUSIONS

Allergic symptoms to ash pollen can be the consequence of sensitization to cross-reactive allergens from other sources. The fact that ash pollen-allergic patients can be discriminated on the basis of their specific IgE reactivity profile to highly or moderately cross-reactive allergens has implications for the selection of appropriate forms of treatment.

Privet pollen (Ligustrum sp.) as potential cause of pollinosis in the city of Cordoba, south-west Spain

BACKGROUND

Privet pollen rarely accounts for more than 1% of the annual total of daily pollen concentrations measured in a city; however in areas where these trees are widely used as ornamentals the amounts collected may be high enough to cause allergy symptoms.

METHODS

Air samples taken with volumetric particle samplers Lanzoni VPPS 1000 (Lanzoni s.r.l., Bologna, Italy) show that there are differences in privet pollen concentrations measured in neighbourhoods with a high incidence of privet trees and in those taken at some distance from the source of emission.

RESULTS

The results suggest that differences are due to the short dispersal range of the pollen grains once released from the plant, resulting from both the entomophilous nature of the plant and the large size of the pollen grains. Urban design, moreover, may play an important role in impeding pollen grain dispersion if the air cannot flow freely through long, narrow avenues. Another important consideration is that the last stages of the flowering period of privet overlaps with the flowering period of olive trees, the main allergen in the area. The fact that the two pollen types share common allergens means that there may be a cross-reaction between olive tree pollen and privet pollen.

CONCLUSIONS

Privet pollen should be considered as a potential causative agent of local allergy problems in areas where its presence is extensive and is in combination with other allergens.

Localization of transcripts corresponding to the major allergen from olive pollen (Ole e I) by electron microscopic non-radioactive in situ RT-PCR

In situ reverse transcription-PCR of mRNAs corresponding to the olive major allergen (Ole e I) has been tested at the ultrastructural level in mature olive pollen. The transcripts were present in the cytoplasm of both the vegetative and the generative cells, frequently associated to ribosomes in the endoplasmic reticulum. No labeling was detected in the pollen wall, nor in vacuoles, lipid bodies, plastids or mitochondria. Localization of the major olive allergen at ultrastructural level showed the protein present mainly in the lumen of the endoplasmic reticulum vesicles or pockets scattered in the cytoplasm, and in the outer region of the pollen exine. The results confirm the rough endoplasmic reticulum as the cell system involved in both the synthesis and storage of this protein. This is the first report of in situ RT-PCR on plant material at the ultrastructural level. The method described for mRNA amplification and detection is confirmed as a valuable tool for studying gene expression in plant material.

Preliminary assessment of the immune response to Olea europaea pollen extracts encapsulated into PLGA microspheres

In this study, poly (D,L-lactide-co-glycolide) (PLGA) microspheres encapsulating Olea europaea pollen extracts were prepared by using the double emulsion (w/o/w) based on a solvent evaporation/extraction method. The resulting microspheres were 1.93 microns in size. The total allergen loading and surface-associated allergen were 8 and 0.64%, respectively. The release of the allergen from the microspheres showed a biphasic profile with an initial burst release followed by a sustained release phase. Finally, the polyacrylamide gel electrophoresis (SDS-PAGE) results showed that the encapsulation process does not affect the stability of the protein. We describe here some preliminary observations concerning the use of these microspheres as parenteral antigen delivery systems for immunization with O. europaea pollen extracts, in a small animal model, the mouse.