Original article
Mechanisms of allergic and immune disease
Detection of airborne Par j 1 and Par j 2 allergens in relation to Urticaceae pollen counts in different bioclimatic areas

https://doi.org/10.1016/j.anai.2010.04.019Get rights and content

Background

In aerobiological studies, the Parietaria pollen type usually includes all Parietaria and Urtica species found in the area. Given that Urtica is a nonallergenic plant, the pollen counts report incomplete information on the presence of allergens in the atmosphere. Discordance between the pollen concentrations of Urticaceae and allergic symptoms has been observed in patients with pollinosis.

Objective

To compare the Urticaceae pollen counts with the Par j 1 and Par j 2 aeroallergen concentrations from 2 different Spanish geographic areas to determine the allergenic load in the atmosphere.

Methods

Hirst-type volumetric traps and Burkard Cyclone samplers were used for pollen counts and aeroallergen capture, respectively. The quantification of Par j 1 and Par j 2 allergens was performed using specific 2-site antibody enzyme-linked immunosorbent assay. Transmission electron microscopy and immunocytochemical techniques were applied to localize these allergens in the orbicules.

Results

Differences between areas and years were obtained in both pollen and aeroallergen concentrations. Despite the lower pollen counts recorded in Cartagena, higher aeroallergen concentrations were registered compared with Ourense. A lower correlation was achieved between Urticaceae pollen concentrations and aeroallergen levels, with a maximum positive significant correlation (adjusted R2 = 0.466, P < .001). Intense labeling of Par j 1 and Par j 2 proteins was observed in the orbicules, the tapetal membrane, and the tapetal tissue remnants.

Conclusion

This method may be valuable for epidemiologic research to establish correlations between concentrations of Parietaria aeroallergens and clinical symptoms. Therefore, the measurement of aeroallergens should be incorporated into the aerobiological studies with clinical applications.

Introduction

The airborne content of pollen grains is normally quantified using conventional pollen counts and microscopy identification techniques. However, discordance between atmospheric pollen concentration and allergic symptoms has been observed.1 The presence of airborne allergen submicronic particles in the atmosphere and their association with increasing asthma and deaths due to respiratory and cardiovascular diseases have been found by different authors.2 The different processes that occur in the anther and pollen grains can provoke the presence of allergenic particles in the atmosphere. Allergens are released from pollen grains in wet conditions similar to the in vitro and in vivo germination processes.3, 4 These allergens could also be dispersed as microdroplets and deposited on different parts of the plants, such as leaves and stems, and later dispersed again into the atmosphere.5 On the other hand, pollen allergens were recently localized in the tapetal tissue of Fraxinus angustifolia from the microsporogenesis stage to the dehiscence stage.6 As a result, we believe that the allergenic remnants of the tapetal membrane may be liberated into the atmosphere, provoking an increase in allergenic particles. In addition, orbicules or Ubish bodies emitted from the dehiscent anthers are also considered a possible origin of the pollen-derived paucimicronic allergenic particles.3, 6, 7, 8

The Urticaceae family includes a number of well-known plants, Urtica and Parietaria being the most widespread. Parietaria is a wind-pollinated weed that includes the most important allergenic plants in the Mediterranean countries, and Parietaria judaica L is 1 of the most common species of this genus found in the countryside and urban areas. P judaica pollen has a prevalence of 60% to 80% in Italy and Greece and 25% to 50% in Spain and southern France.9 In Europe, the sensitization to P judaica is higher in the south than in the north.10 In Spain, depending on the area, the sensitization reaches between 25% and 50% in the Mediterranean area, whereas in the northwest area the prevalence is lower (6%-25%).11

Allergic symptoms, including bronchial asthma, can appear in patients allergic to Parietaria, especially in patients monosensitized to Parietaria.12 The prevalence of IgE reactivity for Parietaria allergens seems to depend on the geographic area where the patients live.13 Par j 1 and Par j 2 are the 2 main allergens that belong to the family of nonspecific lipid transfer proteins, with high homology, identical conformation, and 3 similar allergenic epitopes.14

The quantification of airborne allergens together with pollen grain counts should be performed in the control of Parietaria pollinosis because of its high allergenic potential, the difficulty in distinguishing its pollen grains from other nonallergenic species of Urticaceae, and the probable existence of aeroallergen paucimicronic particles. This information may be helpful to the diagnosis and treatment of patients with Parietaria pollen allergy, and it makes it possible to establish correlations with clinical symptoms, as well as to see whether differences among geographic areas are found. The aim of this study was to compare the Urticaceae pollen counts with the aeroallergen Par j 1 and Par j 2 concentrations in 2 different geographic areas in Spain to determine the allergenic load in the atmosphere and to establish regional and climatic characteristics between them.

Section snippets

Study Area

Airborne Urticaceae pollen and Par j 1 and Par j 2 were quantified in Cartagena and Ourense, Spain. Cartagena is located in the Southeast of the Iberian Peninsula and belongs to the Mediterranean Xeric Oceanic region, and Ourense is situated in the Northwest of the Iberian Peninsula in the transition between the Mediterranean and Eurosiberian regions. The most important species present in Ourense are P judaica, Urtica dioica, Urtica membranacea, and Urtica urens, with U urens being the most

Pollen Counts

Urticaceae pollen is detected throughout the year, but in the spring it achieves the highest pollen concentrations, with the exception of 2 peaks registered in February 2007 in Cartagena (Figure 1). Urticaceae pollen represented 7.86% and 9.4% of the total annual pollen registered in 2007 in Cartagena and Ourense, respectively, and 6.85% and 8.7% in 2008. In Cartagena, the total annual Urticaceae pollen counts were 1,693 and 1,293 pollen grains in 2007 and 2008, respectively. The SDs were 8.1

Pollen Count vs Par j 1 and Par j 2 Airborne Concentration

Asthma and bronchial allergy symptoms are frequently observed in patients allergic to Parietaria pollen, but the time of pollen exposure and the time that symptoms occur often do not coincide.9, 21 In the results shown, a weak correlation was observed between daily Urticaceae pollen counts and daily Par j 1 and Par j 2 concentrations. This dissimilarity between both variables was especially found in Cartagena at one peak in May 2007 and various peaks in 2008, as well as in Ourense at various

Acknowledgments

We are grateful to the Scientific Technical Services of the University of Barcelona for their careful preparation of samples for transmission electron microscopy and to the Governmental Agency of Meteorology of Spain for providing us with the meteorologic data. We also thank Tanya G. Johnson for her valuable help in reviewing the English text.

References (40)

  • M. Suárez-Cervera et al.

    Immunocytochemical localization of Cry j 1, the major allergen of Cryptomeria japonica (Taxodiaceae) in Cupressus arizonica and Cupressus sempervirens (Cupressaceae) pollen grains

    Sex Plant Reprod

    (2003)
  • M. Suárez-Cervera et al.

    The role of allergenic proteins Pla a 1 and Pla a 2 in the germination of Platanus acerifolia pollen grains

    Sex Plant Reprod

    (2005)
  • P.E. Taylor et al.

    Birch pollen rupture and the release of aerosols of respirable allergens

    Clin Exp Allergy

    (2004)
  • F.J. Rodríguez-Rajo et al.

    The relationship between tapetum cells and microspores based on protein localization in Fraxinus angustifolia (Oleaceae) pollen grains

    Int J Plant Sci

    (2010)
  • G. El-Ghazaly et al.

    Localization and release of allergens from tapetum and pollen grains of Betula pendula

    Protoplasma

    (1999)
  • S. Vinckier et al.

    The potential role of orbicules as a vector of allergens

    Allergy

    (2001)
  • M. Masullo et al.

    Respiratory allergy to Parietaria in 348 subjects

    Allergol Immunopathol

    (1996)
  • P.J. Bousquet et al.

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

    Allergy

    (2007)
  • F.J. Subiza Garrido-Lestache et al.

    Pólenes de interés en alergología en nuestro medio

  • G. D'Amato et al.

    Thunderstorm-asthma and pollen allergy

    Allergy

    (2007)
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    Disclosures: Authors have nothing to disclose.

    Funding Sources: This study was supported by grants CGL2006-15103-C04-01, 02, 03, 04 from the Spanish Sciences and Innovation Ministry.

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