Allergenic pollen pollinosis in Madrid

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.

A comprehensive aerobiological study of the airborne pollen in the Irish environment

Respiratory allergies triggered by pollen allergens represent a significant health concern to the Irish public. Up to now, Ireland has largely refrained from participating in long-term aerobiological studies. Recently, pollen monitoring has commenced in several sampling locations around Ireland. The first results of the pollen monitoring campaigns for Dublin (urban) and Carlow (rural) concerning the period 2017-2019 and 2018-2019, respectively, are presented herein. Additional unpublished pollen data from 1978-1980 and, 2010-2011 were also incorporated in creating the first pollen calendar for Dublin. During the monitoring period over 60 pollen types were identified with an average Annual Pollen Integral (APIn) of 32,217 Pollen × day/m³ for Dublin and 78,411 Pollen × day/m³ for Carlow. The most prevalent pollen types in Dublin were: Poaceae (32%), Urticaceae (29%), Cupressaceae/Taxaceae (11%), Betula (10%), Quercus (4%), Pinus (3%), Fraxinus (2%), Alnus (2%) and Platanus (1%). The predominant pollen types in Carlow were identified as Poaceae (70%), Urticaceae (12%), Betula (10%), Quercus (2%), Fraxinus (1%) and Pinus (1%). These prevalent pollen types increased in annual pollen concentration in both locations from 2018 to 2019 except for Fraxinus. Although higher pollen concentrations were observed for the Carlow (rural) site a greater variety of pollen types were identified for the Dublin (urban) site. The general annual trend in the pollen season began with the release of tree pollen in early spring, followed by the release of grass and herbaceous pollen which dominated the summer months with the annual pollen season coming to an end in October. This behaviour was illustrated for 21 different pollen types in the Dublin pollen calendar. The correlation between ambient pollen concentration and meteorological parameters was also examined and differed greatly depending on the location and study year. A striking feature was a substantial fraction of the recorded pollen sampled in Dublin did not correlate with the prevailing wind directions. However, using non-parametric wind regression, specific source regions could be determined such as Alnus originating from the Southeast, Betula originating from the East and Poaceae originating from the Southwest.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10453-022-09751-w.

Clinical impact and immunological alterations in asthmatic patients allergic to grass pollen subjected to high urban pollution in Madrid

BACKGROUND

The prevalence of asthma has increased in recent decades. Among the reasons for this increase is environmental pollution. Pollutants cause bronchial inflammation and introduce modifications in the pollen, making it more allergenic.

OBJECTIVE

Assess symptoms and medication requirements of asthmatic patients with grass allergies in Madrid (high urban pollution) and Ciudad Real (low pollution), and simultaneously evaluate the in vitro effects that pollen collected in both areas has on the immune cells of patients.

METHODS

During two pollen seasons, patients from both cities were included. The patients recorded their symptoms and the asthma medication they took daily. In both cities, pollen data, pollutants and meteorological variables were evaluated. The response to different cell populations from patients in both areas were analysed after "in vitro" stimulation with pollen from both cities.

RESULTS

The symptoms and medication use of the patients in Madrid was 29.94% higher. The NO₂ concentration in Madrid was triple that of Ciudad Real (33.4 vs. 9.1 µg/m³ of air). All other pollutants had very similar concentrations during the study period. Pollen from the high pollution area caused a significant enhancement of T-CD8+ and NK cells proliferation compared with pollen of low pollution area, independently of the patient's origin.

CONCLUSION

Asthmatic patients from Madrid have a worse clinical evolution than those from Ciudad Real because of higher levels of urban pollution, and this could be driven by the higher capacity of pollen of Madrid to activate T-CD8+ and NK cells.

Influence of environmental drivers on allergy to pollen grains in a case study in Spain (Madrid): meteorological factors, pollutants, and airborne concentration of aeroallergens

The aim of this study was to compare airborne levels of Phl p 1 and Phl p 5, with Poaceae pollen concentrations inside and outside of the pollen season, and to evaluate their association with symptoms in grass allergic patients and the influence of climate and pollution. The Hirst and the Burkard Cyclone samplers were used for pollen and allergen quantification, respectively. The sampling period ran from 23 March 2009 to 27 July 2010. Twenty-three patients with seasonal allergic asthma and rhinitis used an electronic symptom card. The aerosol was extracted and quantified for Phl p 1 and Phl p 5 content. Descriptive statistics, non-parametric paired contrast of Wilcoxon, Spearman's correlations, and a categorical principal component analysis (CatPCA) were carried out. Significant variations in pollen, aeroallergen levels, pollen allergen potency, and symptoms score were observed in this study. Phl p 5 pollen allergen potency was higher at the beginning of the 2010 grass pollen season. Presence of Phl p 1 outside the pollen season with positive O₃ correlation was clinically relevant. 45.5% of the variance was explained by two dimensions in the CatPCA analysis, showing the symptom relationships dissociated in two dimensions. In the first one, the more important relationship was with grass pollen grains concentration and Phl p 5 and to a lesser extent with Phl p 1 and levels of NO₂ and O₃, and in the second dimension, symptoms were associated with humidity and SO₂. Clinically relevant out-season Phl p 1 was found with a positive O₃ correlation. The effect of climate and pollution may have contributed to the higher seasonal allergic rhinitis symptom score recorded in 2009.

Allergic reactions to genus Morus plants: a review

Mulberry is a plant belonging to the family Moraceae, and genus Morus. Allergic sensitization to mulberries has been reported as both food allergy or respiratory allergy, and cross-reactivity between mulberries and other pollens or fruits was described. Clinically, in the articles reporting mulberry allergy, the reactions included respiratory allergy, airborne contact urticaria, anaphylaxis, oral allergy syndrome, and food induced urticaria. As far as cross-reactivity is concerned, the allergens identified thus far in mulberries include pathogenesis-related (PR)10 proteins, with sequence identity to Bet v 1 from birch, lipid transfer (LTP)1 proteins with identity with LTPs from Rosaceae family plants, panallergens groups, and also ubiquitin-like protein and cystatin-like protein. The two latter proteins account for cross-reactions with Parietaria judaica and Olea europaea. Such large cross-reactivity warrants to pay particular attention to the risk of systemic reactions to foods, particularly in subjects sensitized to birch, parietaria or olive pollens. In fact, the increasing use of mulberry as a food product, which is encouraged by its remarkable antioxidant power, expose sensitized patients to possible reactions after ingesting foods, dietary supplements or nutraceuticals containing mulberry. Mulberry allergenicity can vary according to the processing methods used since some allergens are thermostable and other loss their reactivity during heating.

Three-dimensional label-free imaging and analysis of Pinus pollen grains using optical diffraction tomography

The structure of pollen grains is related to the reproductive function of the plants. Here, three-dimensional (3D) refractive index maps were obtained for individual conifer pollen grains using optical diffraction tomography (ODT). The 3D morphological features of pollen grains from pine trees were investigated using measured refractive index maps, in which distinct substructures were clearly distinguished and analyzed. Morphological and physiochemical parameters of the pollen grains were quantified from the obtained refractive index (RI) maps and used to quantitatively study the interspecific differences of pollen grains from different strains. Our results demonstrate that ODT can assess the structure of pollen grains. This label-free and rapid 3D imaging approach may provide a new platform for understanding the physiology of pollen grains.

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%).

What are the most important variables for Poaceae airborne pollen forecasting?

In this paper, the problem of predicting future concentrations of airborne pollen is solved through a computational intelligence data-driven approach. The proposed method is able to identify the most important variables among those considered by other authors (mainly recent pollen concentrations and weather parameters), without any prior assumptions about the phenological relevance of the variables. Furthermore, an inferential procedure based on non-parametric hypothesis testing is presented to provide statistical evidence of the results, which are coherent to the literature and outperform previous proposals in terms of accuracy. The study is built upon Poaceae airborne pollen concentrations recorded in seven different locations across the Spanish province of Madrid.

Temporal modelling and forecasting of the airborne pollen of Cupressaceae on the southwestern Iberian Peninsula

Cupressaceae includes species cultivated as ornamentals in the urban environment. This study aims to investigate airborne pollen data for Cupressaceae on the southwestern Iberian Peninsula over a 21-year period and to analyse the trends in these data and their relationship with meteorological parameters using time series analysis. Aerobiological sampling was conducted from 1993 to 2013 in Badajoz (SW Spain). The main pollen season for Cupressaceae lasted, on average, 58 days, ranging from 55 to 112 days, from 24 January to 22 March. Furthermore, a short-term forecasting model has been developed for daily pollen concentrations. The model proposed to forecast the airborne pollen concentration is described by one equation. This expression is composed of two terms: the first term represents the pollen concentration trend in the air according to the average concentration of the previous 10 days; the second term is obtained from considering the actual pollen concentration value, which is calculated based on the most representative meteorological parameters multiplied by a fitting coefficient. Temperature was the main meteorological factor by its influence over daily pollen forecast, being the rain the second most important factor. This model represents a good approach to a continuous balance model of Cupressaceae pollen concentration and is supported by a close agreement between the observed and predicted mean concentrations. The novelty of the proposed model is the analysis of meteorological parameters that are not frequently used in Aerobiology.

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.

A, Canales M, Morales S. RGE, Mardones P. P, Leiva G. MA. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies.

An IgE-Mediated Allergic Reaction Caused by Mulberry Fruit

Mulberry (Morus spp.) is a widespread deciduous tree and its fruit is commonly eaten in Korea and eastern Asia. Some reports demonstrate that mulberry fruit is a food allergen in the Mediterranean area. However, there has been no report of systemic allergic reactions after ingesting mulberry fruit in Korea. An 18-year-old boy with a mulberry fruit allergy visited our allergy clinic. He had experienced generalized urticaria, chest tightness, breathing difficulty, and abdominal cramping after ingesting mulberry fruit. The patient had a positive skin reaction to mulberry fruit extract (mean wheal size, 5 mm). We performed an ELISA to detect specific IgE antibody (Ab) to mulberry fruit extract in the patient's serum compared to those of non-atopic healthy controls and birch-sensitized individuals. Specific IgE Ab to mulberry fruit extract was detected in the patient's serum, as compared to non-atopic healthy controls. Another subject, who was strongly sensitized to birch pollen, also had a positive serum-specific IgE Ab to mulberry fruit. We performed IgE immunoblot analysis using the patient's and the other subject's sera, who had serum-specific IgE to mulberry fruit, to identify the IgE-binding component. An identical IgE-binding component to mulberry extract was detected in the two subjects at around 17 kDa, and which might be PR 10 of Bet v 1. In conclusion, mulberry fruit could induce a systemic allergic reaction through an IgE-mediated mechanism, and cross-reactivity might occur between mulberry fruit and birch pollen.

The weak effects of climatic change on Plantago pollen concentration: 17 years of monitoring in Northwestern Spain

Plantago L. species are very common in nitrified areas such as roadsides and their pollen is a major cause of pollinosis in temperate regions. In this study, we sampled airborne pollen grains in the city of León (NW, Spain) from January 1995 to December 2011, by using a Burkard® 7-day-recording trap. The percentage of Plantago pollen compared to the total pollen count ranged from 11% (1997) to 3% (2006) in the period under study. Peak pollen concentrations were recorded in May and June. Our 17-year analysis failed to disclose significant changes in the seasonal trend of plantain pollen concentration. In addition, there were no important changes in the start dates of pollen release and the meteorological parameters analyzed did not show significant variations in their usual trends. We analyzed the influence of several meteorological parameters on Plantago pollen concentration to explain the differences in pollen concentration trends during the study. Our results show that temperature, sun hours, evaporation, and relative humidity are the meteorological parameters best correlated to the behavior of Plantago pollen grains. In general, the years with low pollen concentrations correspond to the years with less precipitation or higher temperatures. We calculated the approximate Plantago flowering dates using the cumulative sum of daily maximum temperatures and compared them with the real bloom dates. The differences obtained were 4 days in 2009, 3 days in 2010, and 1 day in 2011 considering the complete period of pollination.

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.

IgE Reactivity to Common Cypress (C. sempervirens) Pollen Extracts: Evidence for Novel Allergens

Background

Cypress pollen is becoming an increasing cause of respiratory allergy in some regions worldwide.

Objective

The aim of this study was to determine some of the main allergens implicated in the common cypress (C. sempervirens) pollen allergy.

Methods

Pollen extracts were optimized by using some detergents and chaotropes in order to solubilize both water and non-water soluble proteins. C. sempervirens pollen extracts were resolved by one and two dimensional electrophoresis and assayed with sera of allergic subjects.

Results

Five predominant allergens with apparent molecular masses ranging from 14 to 94 kDa were detected. Two principal IgE-binding patterns were clearly distinguishable: a first one represents patients with a heterogeneous IgE reactivity to several allergens (pI 3.5-8.5) with molecular masses ranging from 35 to 94 kDa (HMW). The second one corresponds to little less than 50 percent of tested patients with specific IgE binding to 2-3 spots (pI 10-11) of about 14 kDa and weak or no reactivity to HMW allergens.

Conclusion

The extraction of water insoluble proteins allows the revelation of novel allergens as well as different allergen sensitization patterns in the C. sempervirens pollen allergy. These novel IgE reactive components may subsequently be applied to expand the panel of well-defined cypress pollen molecules for a more efficient allergen-based diagnosis and therapy.

Influence of pollen level on hospitalizations for asthma

The effect of pollen level on asthma hospitalizations is still under debate. The aim of this study was to analyze hospital admissions due to asthma and its relation with environmental pollen and meteorological factors. During 13 years, we included every patient admitted with asthma as primary or secondary diagnosis. For this purpose, we used a case-crossover analysis to compare pollen concentrations at the time of admission with values of the same variables 2 to 6 days before admission. We included 6,687 hospital admissions. High maximum temperature and low humidity were associated with lower risk of asthma admissions. High mean pollen levels exerted a moderate effect and high maximum pollen levels led to a dramatic increase of hospital admissions due to asthma, especially among females. In conclusion, environmental pollen level increases the risk of asthma hospital admissions.

How molecular diagnosis can change allergen-specific immunotherapy prescription in a complex pollen area

BACKGROUND

The identification of disease-eliciting allergens is a prerequisite for accurate prescription of allergen-specific immunotherapy (SIT). The aim of this study was to determine whether molecular diagnosis (MD) may change indication and allergen prescription of SIT.

METHODS

A total of 141 patients with allergic rhinoconjunctivitis and/or asthma sensitized to pollen with or without concomitant food allergy were included. Skin prick testing with a panel of aeroallergens and a microarray-based panel of allergens (ISAC(®); Phadia, Sweden) was performed in all patients. Prior to learning the results of molecular diagnosis, three of the authors reached a consensus on the indication of SIT and use of allergens following EAACI recommendations, basing their judgment on clinical history and skin prick test results before and after obtaining the ISAC results. The agreement coefficient (kappa index) was used to analyze the results.

RESULTS

Fifty-nine percent of the patients were women with a mean age of 31 ± 13.63. Agreement in SIT indication before and after ISAC(®) results was found in only 62 (46%) patients (kappa = 0.1057 ± 0.0413). Concerning allergens used in the most common prescriptions before and after MD results, we obtained the following results: κ = 0.117 ± 0.0825 for grass; κ = 0.1624 ± 0.0639 for olive; κ = 0.0505 ± 0.0548 for olive and grass; κ = 0.1711 ± 0.0471 for grass and cypress; κ = 0.1897 ± 0.0493 for grass and London plane; κ = 1 ± 0.0842 for olive and cypress, and κ = 0.3586 ± 0.0798 for other combinations.

CONCLUSIONS

There was very low agreement concerning indication and use of allergens for SIT before and after performing MD. This discrepancy emphasizes the usefulness of MD, at least in areas of complex sensitization to pollen, in determining correct indication of SIT.

Human exposure to allergenic pollens: a comparison between urban and rural areas

BACKGROUND

Pollinosis is found more frequently in urban areas than in rural environments. This could be partly related to the different types of pollen exposure in these dissimilar areas. The objective of this study was to compare the distribution of pollen in these environments across an urbanization gradient.

METHODS

Daily pollen abundances were obtained in France using Hirst-type sensors. Sampling was conducted from January to June in 2003 and 2006 in a rural area, a semi-rural area and in two urban areas, which were characterized by several urbanization criteria.

RESULTS

Total allergenic pollen abundance was higher in rural and semi-rural areas than in urban areas irrespective of the sampling year. Multivariate analyses showed that pollen exposures differed according to the type of area and were strongly explained by the urbanization gradient. Grass, ash, birch, alder, hornbeam, hazel and plantain pollen quantities exceeded the allergy threshold more often in rural settings than in urban areas. In urban areas, only plane pollen quantities exceeded the allergy threshold more often than in rural areas.

CONCLUSIONS

Allergenic pollen exposure is higher in rural areas than in urban areas, and the most abundant pollen in each area did not originated from the same taxa. This result should be taken into account in epidemiological studies comparing allergies in rural and urban areas to adapt the panel of pollen extracts for human environmental exposure. In addition, this study highlights that some ornamental trees produce a large number of allergenic pollens and provide new sources of aeroallergens.

Airborne pollen calendar of Salamanca, Spain, 2000-2007

BACKGROUND

The determination of pollen types and their proportions in the atmosphere of relevant urban areas have increasingly been evaluated in different regions. The final goal has been to elaborate a pollen calendar, providing data about the occurrence of pollen grains in the air, thus permitting medical treatment and prophylaxis.

METHODS

An aerobiological study was carried out in the atmosphere of the city of Salamanca, Spain, during eight years (2000-2007) by means of a Hirst type volumetric spore trap. A pollen calendar was elaborated following exponential classes obtained from 10-day average concentrations of the main pollen types.

RESULTS

Mean annual pollen index was 16,916, coming from 72 different types of pollen. During the studied period, an increase of annual pollen levels was registered by means of regression analysis index. The most important types of pollen were Quercus, Poaceae, Cupressaceae, Olea, and Plantago. Arboreal pollen grains (62.7%) were more represented in airborne pollen spectrum than non-arboreal pollen (37.3%). Airborne pollen levels were particularly high between April and July, showing the highest values in May and June.

CONCLUSIONS

In aerobiological terms Poaceae pollen seems to be a major risk for potential sensitised individuals due to its known allergenicity and its high atmospheric concentrations between late spring and early summer, followed by Cupressaceae, Olea and Platanus pollen grains, and taking into account the possible role of Fraxinus and Quercus in early spring allergenic courses and in processes of cross-sensitivity, respectively.

Platanus pollen allergen, Pla a 1: quantification in the atmosphere and influence on a sensitizing population

BACKGROUND

The allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. The prevalence of allergy to Platanus is currently moderate, although the percentage of monosensitized patients is low. This hinders accurate interpretation of the relationship between the amount of pollen inhaled and the patient's symptoms.

OBJECTIVE

This study aims to investigate the relationship between the atmospheric concentration pattern of Pla a 1 aeroallergen and the Platanus pollen.

METHODS

The pollen sampling was carried out using a Hirst-type volumetric trap (Burkard(©) ) for pollen grains and a Burkard Cyclone sampler (Burkard(©) ) for Pla a 1 allergen. Serum-specific IgE levels to Acer sp., Artemisia vulgaris, Betula alba, Chenopodium album, Cupressus arizonica, Cynodon dactylon, Fraxinus excelsior, Lolium perenne, Pinus sp., Plantago lanceolata, Platanus acerifolia, Populus sp., Quercus ilex and Taraxacum officinale allergens were determined using the EAST System (Hytec specific IgE EIA kit; Hycor Biomedical, Kassel, Germany).

RESULTS

The aerobiological dynamics of Platanus pollen grains and Pla a 1 differed considerably, particularly during the Platanus pollination period. Of the 118 subjects tested, sera from 34 contained specific IgE to Platanus pollen and all of them had specific IgE to other pollen types.

CONCLUSIONS

The presence of the aeroallergen Pla a 1 in the atmosphere appears to be independent of Platanus pollen counts over the same period, which may be contributing to allergic symptoms and sensitization. The number of polysensitized patients displaying allergy to Platanus suggested that allergic symptoms were caused by co-sensitization or cross-reactivity involving a number of allergenic particles.

Pollen aeroallergens in the Washington, DC, metropolitan area: a 10-year volumetric survey (1998-2007)

BACKGROUND

Local aeroallergen surveys identify and establish patterns of prevalence for tree, grass, and weed species that enable the clinician to more effectively select allergens for skin testing and therapy.

OBJECTIVES

To determine peak pollination periods, atmospheric concentrations, and year-to-year variation for identified tree, weed, and grass aeroallergens and examine the influence of selected meteorological parameters.

METHODS

Atmospheric sampling for pollen aeroallergens was performed using a volumetric rotating-arm impaction sampler. The Spearman correlation coefficient was used to determine the relationship between daily counts and selected meteorological parameters.

RESULTS

Previous findings for area trees, conducted at a different location, are corroborated. Predominant pollen types include Quercus, Cupressaceae, Pinaceae, Morus, Betulaceae, Acer, Platanus, Fraxinus, Poaceae, and Ambrosia. Early flowering weeds (Rumex and Typha) and Poaceae overlap with peak tree season in April. Biphasic seasons are noted for Poaceae and Ulmus. Tree pollen accounts for 91.2%, weeds 3.8%, and grasses 3.2% of total annual pollen yield. Variation in overall pollen production is evident from year to year. High production years for some species are low for others. Cyclic pollinating patterns for Alnus, Betulaceae, and Fagus were observed. Grass and weed pollen correlated positively with maximum temperature and dew point; however, the results for individual tree species were variable.

CONCLUSION

The Washington, DC, metropolitan area is host to a variety of tree, weed, and grass species that produce copious amounts of pollen. Further investigation into year-to-year variation with respect to inherent cycling and meteorological influences is warranted.

Cluster immunotherapy with a glutaraldehyde-modified mixture of grasses results in an improvement in specific nasal provocation tests in less than 2.5 months of treatment

BACKGROUND

Cluster immunotherapy is becoming increasingly used. It allows for a rapid build up phase and the administration of higher doses of allergen in a shorter period of time.

OBJECTIVES

To evaluate the effect of short-term pre-seasonal immunotherapy using a glutaraldeyde-modified allergen vaccine in reducing specific nasal hyperreactivity in nasal challenge tests.

MATERIALS AND METHODS

Thirty-three patients were selected. All patients had a positive history of allergic rhinitis and skin tests to grass pollen, although most of them (72.7%) were sensitized to other allergens as well. The study was conducted outside of the pollen season and the patients did not receive any pharmacological treatment during this period of time. Two randomized groups of patients were established; Group A: 22 patients (13 females and nine males) and Group B, 11 control patients (seven females and four males). Patients in Group A received immunotherapy with a vaccine containing 50% of the wild grasses Trisetum paniceum and Dactylis glomerata. All patients underwent titrated nasal provocation tests (NPT) before and after completion of the study (2.3 and 2.8 months for Groups A and B, respectively). The administration schedule consisted of 0.1 and 0.2 mL at day 1, followed by 0.3 and 0.5 mL at day 7, 0.5 mL after 2 weeks followed by 0.5 mL monthly. A single vial was used containing an allergen concentration of 10 000 TU/mL (105 microg of total protein and 24.6 microg of Group 1 plus 5 allergens/mL). A mean of 6.5 injections were administered to Group A patients between NPTs.

RESULTS

There were no significant differences between both groups at the beginning of the study (P=0.48). At the end, only Group A patients needed significant greater threshold concentrations for a positive NPT than at the beginning (P=0.002).

CONCLUSIONS

A short-term cluster pre-seasonal inmunotherapy with a modified vaccine containing a mixture of grass pollen is effective as determined by an objective measure after only a mean 2.3 months of treatment.

Air pollution and seasonal asthma during the pollen season. A cohort study in Puertollano and Ciudad Real (Spain)

BACKGROUND

Many studies have demonstrated a positive association between air pollutants and emergency visits for asthma. However, few studies have included pollen when analysing this relationship in mild-moderate asthmatic patients.

OBJECTIVE

To determine the importance of the pollutants such as ozone (O(3)), particles (PM(10)), nitrogen dioxide (NO(2)) and sulphur dioxide (SO(2)) in the clinical course of mild-moderate pollen-allergic asthmatic patients from two Spanish towns in La Mancha: Puertollano (high pollution levels) and Ciudad Real (low pollution levels).

METHODS

We used a Poisson regression model to study a cohort of 137 patients from Puertollano and Ciudad Real during two pollen seasons (2000-2001) and analysed the relationship between air pollutant and pollen levels and daily symptoms, the medication used and peak-flow measurements.

RESULTS

The number of asthma symptoms and the mean values of the PM(10), SO(2) and NO(2) levels were higher in Puertollano than in Ciudad Real. In Puertollano, the risk of asthma increased by 6% with a 3-day lag for PM(10), by 8% with a 3-day lag for O(3), by 4% with a 1-day lag for SO(2) and by 15% with a 3-day lag for O(3) when its values exceeded the health threshold (P < 0.05).

CONCLUSIONS

The air pollution levels in Puertollano were associated with an increased risk of asthma symptoms in pollen-allergic asthmatic patients com pared with a similar group from Ciudad Real.

Allergenic pollen and pollen allergy in Europe

The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases.

Immunotherapy with depigmented glutaraldehyde-polymerized extracts: changes in quality of life

BACKGROUND

Immunotherapy (IT) with modified allergens reduces allergic rhinitis (AR) symptoms and medications requirements. Improvement of quality of life (QOL) is a key point in the treatment of AR. The aim of this study was to provide evidence of changes related to the patient's QOL (well-being) induced by a modified (depigmented glutaraldehyde-polymerized) therapeutic vaccine and of its safety.

MATERIAL AND METHODS

Fifty-three patients with a well-documented clinical history of seasonal AR sensitized to Dactylis glomerata and Olea europaea pollens were included in a randomized clinical trial. Twenty-five patients (Group-A) received a mixture of D. glomerata and O. europaea pollen extracts and 28 patients received placebo (group-C). Any adverse event was recorded and graded in accordance with EAACI guidelines. RQLQ was recorded before the treatment (pollen season 2000) and after 1 year of treatment (pollen season 2001). Dose-response skin prick test with each allergen extract was conducted at baseline and at the end of the study.

RESULTS

Each patient received 17 injections during this period. All patients completed the trial and no systemic adverse reactions were recorded. Symptom scores (P<0.001) and medication requirements (P<0.001) were significantly reduced in the IT group during the pollen season. This patient group also experienced greater and statistically significant improvement in overall RQLQ score and in five of the seven domains, all of them surpassing the threshold of 'minimal important difference' of 0.5 points.

CONCLUSIONS

Results of this study provided evidence that IT with depigmented, glutaraldehyde-modified allergen extracts was well-tolerated and added beneficial effects to AR treatment in pollen allergic patients eliciting an improvement in QOL enough to justify a change in the patient's treatment.

Lack of correlation between regional pollen counts and percutaneous reactivity to tree pollen extracts in patients with seasonal allergic rhinitis

BACKGROUND

Although seasonal patterns of tree pollination have been reported, it is unknown if aerobiologic data correlate with patterns of in vivo sensitization.

OBJECTIVE

To evaluate the relationship between regional tree pollen exposure and patterns of in vivo percutaneous reactivity to specific tree pollen extracts in a local patient population with seasonal allergic rhinitis.

METHODS

Patients with spring seasonal allergic rhinitis and percutaneous sensitivity to 1 or more regional tree pollens were studied. Tree pollen counts were collected at the same urban site from 1997 to 2002 and at a suburban site in 2002. Patients underwent skin prick testing with commercial extracts of 15 indigenous tree species. Serum specific IgE measurements were assayed in a subset of sensitized patients.

RESULTS

Of 127 patients who reported symptoms consistent with seasonal allergic rhinitis during the spring pollen season, 93 qualified based on demonstration of at least 1 positive skin prick test result. Mean 5-year pollen counts (1997-2001) and 2002 urban counts were highly correlated (Spearman r = 0.95, P < .001), indicating that year-to-year pollen counts were consistent. No significant correlation was found between mean seasonal pollen counts (urban site, 1997-2001) and frequencies of skin prick test reactivity to specific tree pollen allergens (Spearman r = -0.03, P = .93). No significant relationship was found between 5-year mean tree pollen counts and positive serum specific IgE tests for specific tree pollens (Spearman r = -0.42, P = .30). Eight of 15 species elicited percutaneous reactions in more than 50% of patients (ie, satisfying definition of a major in vivo allergen). However, 6 of the 8 major tree allergens each represented 5% or less of 5-year mean total tree pollen counts.

CONCLUSION

No correlation was found between overall frequencies of in vivo sensitization to tree pollen allergens in a local population and regional pollen exposure data.

Non-linear short-term effects of airborne pollen levels with allergenic capacity on asthma emergency room admissions in Madrid, Spain

BACKGROUND

Several time-series studies have shown positive associations between pollen levels and asthma morbidity. However, few studies have included air pollution as a potential confounder when examining this relationship, and they have only done so on a linear basis.

OBJECTIVE

To investigate the potential non-linear short-term effects of the types of pollen with allergenic capacity across the whole range of exposure on the daily number of asthma-related hospital emergencies in Madrid for the period 1995-1998.

METHODS

Data were collected on the daily number of asthma emergency room admissions and daily average levels of major types of pollen with allergenic capacity: Olea, Plantago, Poaceae and Urticaceae. We used Poisson regression with generalized additive models, controlling for trend and seasonality, meteorological variables, acute respiratory infections and air pollutants. To study the non-linear effect of pollen levels on asthma emergency room admissions, pollens were categorized into five groups defined on the basis of their respective distributions.

RESULTS

The strongest associations were registered in respect of a lag of 1 day for Urticaceae, a lag of 2 days for Plantago, and a day lag of 3 days for Poaceae. Adjustment for the different types of pollen failed to result in major changes. Non-linearities were evident for pollen levels. The greatest increase in risk vs. the reference category (minimum value - 50th percentile) was observed for the categories between the 95th and 99th percentiles, with increases of 32.0% for Plantago, 32.2% for Poaceae and 24.6% for Urticaceae, and between the 99th percentile and the maximum value, with increases of 31.3%, 78.7% and 49.8%, respectively. Olea was not related with asthma emergency room admissions.

CONCLUSIONS

Pollens with allergenic capacity in Madrid are positively associated with asthma-related hospital emergencies. These associations remain stable when simultaneous adjustment is made for the four types of pollen and for air pollutants and meteorological variables. In terms of non-linear effects, Poaceae register the strongest association with asthma emergency room admissions.

[Allergenic pollens in Spain]

Allergenic pollens that cause rhinoconjuctivitis and/or asthma are those from trees or plants that pollinate through the air (anemophilic pollination) and not through insects (entomophilic pollination). Although pollen grains would seem to be too large to easily reach the intrapulmonary airways, the relationship between pollen counts and the presence of asthmatic symptoms is only too evident. This is probably because the allergens inducing seasonal asthma are not only found within pollen grains but also outside the grains in particles of less than 10 mm that are freely found in the atmosphere. The most important pollens producing pollinosis in Spain are those from cypress trees from January-March, birch trees in April (macizo galaico), Platanus hispanica (March-April), grasses and olive trees from April-June, Parietaria from April-July and Chenopodium and/or Salsola from July-September. By geographical areas, the main cause of pollinosis are grasses in the center and north of the peninsula, olive trees in the south (Jaén, Sevilla, Granada, Córdoba) and Parietaria in the Mediterranean coast (Barcelona, Murcia, Valencia).

Cloning and expression of a major allergen from Cupressus arizonica pollen, Cup a 3, a PR-5 protein expressed under polluted environment

BACKGROUND

This paper describes the cloning and expression of the Cupressus arizonica pollen protein Cup a 3. In addition, we present its modulation under polluted environmental conditions. Species of the Cupressaceae family are important because of their high sensitization prevalence.

METHODS

Cup a 3 cloning is based on the sequence of the homologous protein Jun a 3. Cup a 3 was expressed with good yield in the methylotropic yeast Pichia pastoris.

RESULTS

Recombinant Cup a 3 (rCup a 3) contains 199 amino acids, 10 potential phosphorylation sites and no glycosylation sites. By immunoblot 63% of cypress allergic patients had specific immunoglobulin E antibodies against rCup a 3 (n = 104). This major allergen is homologous to members of the pathogenesis-related proteins (PR-5 group) and contributes to the overall allergenicity of C. arizonica pollen. Our results show that the increased expression of Cup a 3 is dependent on the pollution in the area where the pollen has been collected, being higher under polluted conditions.

CONCLUSIONS

Cup a 3 is a PR-5 protein derived from C. arizonica pollen. The expression of the protein under polluted conditions has a direct incidence on the pollen allergenicity, as has been demonstrated by skin tests and Radioallergosorbent test inhibition.

Symptoms of persistent allergic rhinitis during a full calendar year in house dust mite-sensitive subjects

BACKGROUND

Little is known about the natural course of persistent rhinitis symptoms over a prolonged period.

OBJECTIVE

To describe the frequency and severity of nasal symptoms and quality of life (QoL) in house dust mite-sensitive persistent rhinitic subjects and to determine if medication use was related to symptoms.

METHODS

Rhinitics and controls were telephoned fortnightly for 1 year to monitor symptoms. QoL was measured every 3 months.

RESULTS

Thirty-seven rhinitics and 19 controls completed the study. Total nasal symptom scores (TNSS) were 'high' for 65% (95% CI +/- 6%) of the year in rhinitic subjects. When TNSS increased by 1, the likelihood of nasal medication use increased by 25% (95% CI: 7-46%). General and specific QoL were worse in rhinitic subjects than controls (P < 0.04 and <0.0001). Rhinitics with pollen allergy (n = 21) had seasonal variation in the frequency of high nasal symptom scores (P = 0.02).

CONCLUSION

Nasal symptom scores were consistently high in rhinitics, and their QoL was worse than controls, even in general QoL. An increase in nasal symptom score increased the likelihood of nasal medication use. These findings help to characterize the course of persistent rhinitis over a previously unstudied period of 1 year.

Allergy to kiwi

BACKGROUND

Allergy to kiwi fruit is being increasingly reported, but it has never been evaluated by means of a double-blind, placebo-controlled food challenge (DBPCFC) study.

OBJECTIVE

We sought to assess kiwi allergy on the basis of a DBPCFC and identify the patterns of allergen recognition in sensitized patients from a birch-free area.

METHODS

Forty-three patients with allergy symptoms who were sensitized to kiwi were evaluated by means of clinical history, skin tests, IgE determinations, and DBPCFCs. The pattern of allergen recognition was assessed by means of IgE immunoblotting. Sequence analysis of IgE-binding bands was performed by using Edman degradation.

RESULTS

DBPCFCs were performed in 33 patients; 4 patients had experienced severe anaphylaxis, and 6 patients declined informed consent. DBPCFC results were positive in 23 patients and negative in 10 patients. The most frequent clinical manifestation was oral allergy syndrome. Twenty-one percent of the patients were not allergic to pollen. Forty-six percent of patients experienced systemic symptoms, and this happened with higher frequency in patients not allergic to pollen (100%). Twenty-eight percent of the patients were sensitized to latex. The IgE-binding bands in kiwi extract more frequently recognized by patient sera were those of 30, 24, 66, and 12 kd, and they could not be associated with any pattern of kiwi-induced allergic reactions.

CONCLUSION

The results provide evidence that kiwi allergy is not a homogeneous disorder because several clinical subgroups can be established. No definite allergen-recognition pattern was associated with the type of allergic reactions to kiwi. One of 5 patients with kiwi allergy was not allergic to pollen, and these patients had the highest risk of systemic reactions to kiwi.

Clinical characteristics of melon (Cucumis melo) allergy

BACKGROUND

Although melon is a frequent allergy-eliciting fruit, allergic reactions to melon have rarely been reported.

OBJECTIVE

To evaluate and describe the clinical characteristics of melon allergy in melon-allergic patients.

MATERIALS AND METHODS

We evaluated patients allergic to melon and a control group of patients allergic to pollen. The diagnosis of melon allergy was based on a convincing clinical history, positive skin test results (prick-by-prick test), and positive results on oral challenge tests to melon.

RESULTS

A total of 161 patients were included in the study: 66 in the melon allergy group and 95 in the pollen control group. The melon allergy group included 35 female and 31 male patients with a mean age of 26.6 +/- 2.7 years (range, 5-61 years). Although all patients had oral symptoms, 13 (19.7%) of the patients had extraoral symptoms and none experienced generalized urticaria or anaphylaxis. Excluding other Cucurbitaceae fruits, peach, fig, and kiwi most frequently elicited positive skin test results and symptoms. Up to 23% of melon-allergic patients had a concomitant latex sensitization. Melon allergy was especially linked to pollen allergy, since all the melon-allergic patients were also allergic to pollen. Some differential features with respect to the pollen allergy control group were a higher prevalence of asthma (odds ratio [OR], 2.13; P < 0.05) and a statistical increase in the frequency of sensitization to several tree and weed pollens, including Ulmus (OR, 42.8) and Ambrosia (OR, 22.4).

CONCLUSION

The most important conditions linked to melon allergy are pollen allergy (100%), allergy to other nonrelated fruits, mainly peach (up to 62%), and latex sensitivity (up to 23%). Some differential features of the pollinosis in melon allergy were a higher prevalence of asthma and a higher frequency of sensitization to several weed and tree pollens.

Short term effects of airborne pollen concentrations on asthma epidemic

BACKGROUND

Few studies have used time series to investigate the relationship between asthma attacks and aeroallergen levels on a daily basis.

METHODS

This study, based on time series analysis adjusting for meteorological factors and air pollution variables, assessed the short term effects of different types of allergenic pollen on asthma hospital emergencies in the metropolitan area of Madrid (Spain) for the period 1995-8.

RESULTS

Statistically significant associations were found for Poaceae pollen (lag of 3 days) and Plantago pollen (lag of 2 days), representing an increase in the range between the 99th and 95th percentiles of 17.1% (95% confidence interval (CI) 3.2 to 32.8) and 15.9% (95% CI 6.5 to 26.2) for Poaceae and Plantago, respectively. A positive association was also observed for Urticaceae (lag of 1 day) with an 8.4% increase (95% CI 2.8 to 14.4).

CONCLUSIONS

There is an association between pollen levels and asthma related emergencies, independent of the effect of air pollutants. The marked relationship observed for Poaceae and Plantago pollens suggests their implication in the epidemic distribution of asthma during the period coinciding with their abrupt release into the environment.

Cloning and expression of biologically active Plantago lanceolata pollen allergen Pla l 1 in the yeast Pichia pastoris

The glycoprotein Pla l 1 is the major allergen from English plantain (Plantago lanceolata) pollen, which is a common cause of pollinosis in temperate areas. Three complete cDNAs for Pla l 1 isoforms were isolated by PCR using specific 3' and 5' primers. All three Pla l 1 cDNAs code for a 25-residue leader peptide and a 131-residue mature protein that contains two polymorphic positions, an N-glycosylation site at position 107 and six cysteine residues involved in three disulphide bridges. The allergen variant Pla l 1.0101 was produced in Pichia pastoris at a yield of 20 mg per litre of culture as a mixture of non-glycosylated (17 kDa), glycosylated (23 kDa) and dimeric (32-39 kDa) forms. Recombinant Pla l 1 (rPla l 1) was purified by affinity chromatography with an anti-natural Pla l 1 (anti-nPla l 1) monoclonal antibody, and its molecular and immunological properties were compared with the natural allergen by CD spectroscopic analysis, enzymic deglycosylation, lectin-binding assay, immunodetection and ELISA-inhibition assays using sera from plantain-allergic patients. The recombinant allergen is properly folded, as deduced from CD spectra, and the immunodominant allergenic epitopes of the natural allergen are preserved in rPla l 1. These results allow us to conclude that P. pastoris is a convenient system for the efficient production of biologically active rPla l 1, which could have a potential use for clinical purposes. Furthermore, a sequence similarity of Pla l 1 to the major allergen from the olive tree pollen, Ole e 1, is revealed in this work, and the allergenic cross-reactivity between both allergens has been studied.

Clinical efficacy and safety of a depigmented and glutaraldehyde polymerized therapeutic vaccine of Parietaria judaica

BACKGROUND

The inhalation of Parietaria judaica pollen is a common cause of allergic respiratory diseases in the Mediterranean area. The objective of this study was to investigate the safety and clinical efficacy of a chemically modified (depigmented and glutaraldehyde-polymerized) vaccine of Parietaria judaica.

METHODS AND RESULTS

Thirty patients with a well-documented clinical history of seasonal rhinitis and clinical sensitivity to Parietaria judaica pollen were included in a randomized trial during 12 months. The study was conducted following good clinical practices and appropriate consent forms were signed. Patients were divided into 2 groups of 15 individuals; group A received the modified extract and group C did not receive specific immunotherapy. Any adverse event was recorded to assess safety. Symptom scores, symptomatic medication use and the results of specific nasal challenges (before and after 12 months of treatment) were recorded to evaluate clinical efficacy. The treatment schedule consisted of an incremental phase of 5 injections and a maintenance dosage of 0.5 ml per month. Each patient received 14 injections during this period. All the patients completed the trial and no adverse reactions related to immunotherapy were recorded. A significant difference (p < 0.001) in symptom scores and overall use of symptomatic medication was observed between the two groups, being both scores lower in group A. No significant differences in nasal sensitivity existed before treatment among the 2 groups. However, after 12 months, a significant difference (p < 0.05) was observed only in group A patients, who showed a significant improvement in specific nasal challenges.

CONCLUSIONS

Immunotherapy with depigmented and glutaraldehyde-polymerized extract of Parietaria judaica pollen is safe and effective to treat patients with allergic rhinitis and clinical sensitivity to this pollen.

Studies on the carbohydrate moiety of Pla l 1 allergen. identification of a major N-glycan and significance for the immunoglobulin E-binding activity

BACKGROUND

Pla l 1, the major allergen of Plantago lanceolata pollen, is a glycoprotein that contains an N-glycosylation site. Carbohydrate moieties of many allergenic glycoproteins have been reported to be IgE-binding determinants responsible for cross-reactivity among different species.

OBJECTIVE

To identify the kind of linkages and the type of glycans present in Pla l 1 and to investigate their contribution to the allergic response to this allergen.

METHODS

Pla l 1 was deglycosylated by N-glycosidase A and the IgE-binding ability of the unglycosylated protein was evaluated by dot-blot. Identification of beta1 --> 2 xylose and/or alpha1 --> 3 fucose residues in Pla l 1 N-glycan was carried out by incubation with specific antibodies from rabbit antiserum against HRP (anti-HRP). The contribution of this N-glycan to total IgE reactivity was analysed quantitatively by pre-incubation of Pla l 1 with anti-HRP prior to incubation with sera. The role of the carbohydrate moiety of Pla l 1 in cross-reactivity was studied by RAST using unrelated glycoproteins with known sugar composition and structure.

RESULTS

The effectiveness of N-glycosidase A to deglycosylate Pla l 1 and the ineffectiveness of the treatment with PNGase F indicate that Pla l 1 carries a complex N-glycan with an alpha1 --> 3 fucose residue in its structure. Furthermore, the presence of beta1 --> 2 xylose and/or alpha1 --> 3 fucose residues was identified in this N-glycan by means of an ELISA. Pre-incubation of Pla l 1 with an anti-HRP antibody caused a weak but significant reduction in IgE reactivity. Some sera from P. lanceolata-allergic patients reacted positively with four glycoproteins that bear N-glycans of complex type but not with fetuine.

CONCLUSIONS

Pla l 1 is a glycoprotein that carries at least a complex, major N-linked glycan, with a alpha1 --> 3 fucose residue in its structure and probably also a beta1 --> 2 xylose. This glycan moiety does not seem to constitute a relevant allergenic epitope of Pla l 1.

Monoclonal antibodies against the major allergen of Plantago lanceolata pollen, Pla l 1: affinity chromatography purification of the allergen and development of an ELISA method for Pla l 1 measurement

BACKGROUND

Plantago lanceolata (English plantain) pollen is a relevant cause of pollinosis in temperate regions. The major allergen of this pollen, Pla l 1, is recognized by the specific IgE from more than 80% of plantain-sensitive patients. It displays significant sequence homology with the major olive-pollen allergen Ole e 1. The objective was to develop a monoclonal antibody-based ELISA to quantify Pla l 1, and to assess the correlation of Pla l 1 content with the biologic activity of plantain pollen extracts. We also aimed to establish the specificity of the monoclonal antibodies against the potentially cross-reactive allergen Ole e 1, and to investigate the presence of Pla l 1-like proteins in psyllium and melon that have been reported to cross-react with P. lanceolata pollen.

METHODS

After fusion of myeloma cells with spleen cells from a BALB/c mouse, two Pla l 1-specific monoclonal antibodies secreting hybridomas were selected, and the antibodies characterized. One of them (2A10) was used as the capture antibody in an ELISA for Pla l 1 quantitation. An anti-P. lanceolata rabbit serum was used as the second antibody. Pla l 1 was purified by immunoaffinity chromatography and used as the standard in the assay.

RESULTS

The ELISA developed was highly reproducible and sensitive, with a detection limit of 0.1 ng/ml, and a practical working range of 0.4-12 ng/ml. The specificity was demonstrated against a large battery of allergens, including Ole e 1. The concentration of Pla l 1 was measured in 19 extracts of P. lanceolata pollen, and a good correlation was observed between the Pla l 1 content and the allergenic activity of the extracts. Pla l 1 was not detected in psyllium or melon extracts.

CONCLUSION

The results prove the usefulness of the Pla l 1-ELISA for the standardization of extracts of P. lanceolata pollen intended for clinical use.

Prevalence of sensitization to Cupressus sempervirens: a 4-year retrospective study

In the last few years Cupressus sempervirens has been identified as the cause of an increasing number of cases of late winter-early spring pollinosis in Mediterranean countries. We conducted a 4-year retrospective study of a large group of subjects with documented allergic respiratory disease in order to determine the prevalence, clinical significance and annual rate of sensitization to C. sempervirens pollen. Anamnestic data and skin prick tests (SPT) with common aeroallergens and C. sempervirens extract were collected from 1397 subjects (712 male and 685 female) resident in Latium, a region in central Italy, with complaints related to upper- or lower-respiratory-tract disorders or conjunctival disease. Two hundred and forty-three subjects (17.4%) showed positive results to C. sempervirens extract: 47 (19.3%) of them were monosensitized. The annual sensitization rate of SPT positivity to C. sempervirens varied from 7.2% in 1995 to 22% in 1998. All the subjects monosensitized to cypress pollen had symptoms from January through April. Our study suggests that sensitivity to C. sempervirens is responsible for respiratory symptoms in an increasing percentage of subjects. Further studies are needed to determine its frequency at the national level.

Purification and characterization of the main allergen of Plantago lanceolata pollen, Pla l 1

English plantain (Plantago lanceolata) pollen is an important cause of pollinosis in the temperate regions of North America, Australia and Europe. However, very little is known about its allergen composition. The aim of this study was to identify plantain allergens, and to isolate and characterize a major allergen. Allergens were identified by immunoblotting with individual allergic patients' sera. Isolation of the major allergen was achieved by sequential reverse-phase and size-exclusion HPLC. Allergenic characterization was performed by ELISA and immunoblotting after SDS-PAGE with sera from plantain-allergic patients. N-terminal amino acid sequence was established by Edman degradation. Allergograms showed that 13 out of the 14 sera assayed had IgE to a group of proteins with a molecular weight in the range of 16-20 kd, that turned out to be different isoforms or variants of the major allergen Pla l l. Eighteen amino acid residues from the N-terminal end of one of the isoforms, and 10 of three others, were sequenced, and a partial sequence identity with Ole e 1 was found. Prevalence of specific IgE to purified Pla l 1 in plantain allergic patients was 86%, and represents about 80% of the total IgE-binding capacity of the plantain extract. The most relevant allergen from P.lanceolata pollen, Pla l 1, has been purified and characterized. This contributes to a greater knowledge of the allergen composition of this important weed, and clears the way for the standardization of plantain allergen products in terms of major allergen content.

Molecular cloning of major allergen from Cupressus arizonica pollen: Cup a 1

The family Cupressaceae is a relevant source of allergens that causes winter respiratory allergies. Cloning and sequencing the major antigen of Cupressus arizonica is important for a better diagnosis and treatment of sensitized patients. To obtain a full-length complementary DNA for Cup a 1, the major allergen of Cupressus arizonica pollen. It was cloned and sequenced and the recombinant protein was expressed. Messenger RNA from Cupressus arizonica pollen was obtained and the Cup a 1 sequence was established using a 3'-RACE system and primers based on the N-terminal amino acid sequence. Recombinant Cup a 1 was cloned in pBluescript and expressed in a glycosylated form in rabbit reticulocytes. The cDNA was subcloned in pGEX-5X-1 and expressed in Escherichia coli as a fusion protein with GST. Recombinant Cup a 1 is highly homologous with the major allergens of mountain cedar (Jun a 1), Japanese cypress (Cha o 1) and Japanese cedar (Cry j 1). Cup a 1 contains three potential N-glycosylation sites that are different from those found in Jun a 1 and Cry j 1. The cloned protein contains a pectate lyase active site identical to those of Cry j 1 and Jun a 1. The IgE from patients' sera recognizes recombinant Cup a 1, and this reactivity is higher with the glycosylated protein. Cup a 1 has been cloned and sequenced. As expected, the high degree of homology with Cha o 1, Jun a 1 and Cry j 1 explains the cross-reactivity of conifer pollens. Different IgE reactivity with the glycosylated and non-glycosylated protein suggests the importance of carbohydrate moieties in the IgE binding site.