Clinical and immunologic evaluation of Cedrus deodara pollen: a new allergen from India

Climate Change and Pollen Allergy in India and South Asia

Increased levels of CO₂ and various greenhouse gases cause global warming and, in combination with pollutants from fossil fuel combustion and vehicular and industrial emissions, have been driving increases in noncommunicable diseases across the globe, resulting a higher mortality and morbidity. Respiratory diseases and associated allergenic manifestations have increased worldwide, with rates higher in developing countries. Pollen allergy serves as a model for studying the relationship between air pollution and respiratory disorders. Climate changes affect the quality and amount of airborne allergenic pollens, and pollutants alter their allergenicity, resulting in greater health impacts, especially in sensitized individuals.

Dolichandrone platycalyx: New entomophilous pollen--A report on pollen sensitization in allergic individuals

BACKGROUND

Dolichandrone platycalyx, commonly known as Nile trumpet tree, is believed to have originated in East Africa. However, this and the variants of this tree are found in Europe, Asia, and America (California and Florida). The tree mostly grows in tropical climates, but temperate species are also found. This study was designed to evaluate the allergenicity of D. platycalyx, one of the most common entomophilous avenue trees in Karnataka state, and to determine the pollen production of D. platycalyx.

METHODS

All of the patients with allergic rhinitis and asthma attending a tertiary care center in South India during August 2007 to March 2008 underwent a detailed clinical evaluation and skin-prick testing to common allergens along with D. platycalyx. Control subjects without any symptoms of respiratory allergy also underwent skin testing. The pollen counts were determined for a mature unopened flower of D. platycalyx.

RESULTS

A total of 317 subjects with respiratory allergy and 30 controls were included in the study. A significant percentage (16.1%) of patients evaluated were observed to be sensitive to Dolichandrone pollen extract by skin-prick testing, whereas none of the control subjects were found to be sensitized. D. platycalyx was the fourth most common sensitizer after Parthenium hysterophorus, Prosopis juliflora, and Artemesia vulgaris. D. platycalyx was found to be a moderate pollen producer at 66,000 pollens/flower.

CONCLUSION

Sensitization to D. platycalyx is common in subjects with respiratory allergies. The clinical relevance of this sensitization and other entomophilous plants needs additional study.

Transition from a Botanical to a Molecular Classification in Tree Pollen Allergy: Implications for Diagnosis and Therapy

Tree pollens are among the most important allergen sources. Allergic cross-reactivity to pollens of trees from various plant orders has so far been classified according to botanical relationships. In this context, cross-reactivities to pollens of trees of the Fagales order (birch, alder, hazel, hornbeam, oak, chestnut), fruits and vegetables, between pollens of the Scrophulariales (olive, ash, plantain, privet, lilac) and pollens of the Coniferales (cedar, cypress, pine) are well established. The application of molecular biology methods for allergen characterization has revealed the molecular nature of many important tree pollen allergens. We review the spectrum of tree pollen allergens and propose a classification of tree pollen and related allergies based on major allergen molecules instead of botanical relationships among the allergenic sources. This molecular classification suggests the major birch pollen allergen, Bet v 1 as a marker for Fagales pollen and related plant food allergies, the major olive pollen allergen, Ole e 1, as a possible marker for Scrophulariales pollen allergy and the cedar allergens, Cry j 1 and Cry j 2, as potential markers for allergy to Coniferales pollens. We exemplify for Fagales pollen allergy and Bet v 1 that major marker allergens are diagnostic tools to determine the disease-eliciting allergen source. Information obtained by diagnostic testing with marker allergens will be important for the appropriate selection of patients for allergen-specific forms of therapy.

Common environmental allergens causing respiratory allergy in India

Respiratory allergy affects all age groups but the children are the worst affected by the respiratory allergy. Bioparticles from different biological sources are the main cause of allergy. Pollen grains, fungal spores, insect and other materials of biological origin form the most important allergen load in the air. For the efficient diagnosis of the allergy and its effective treatment it is very important to know about the prevalence, seasonal and annual variations of aeroallergens of the area. India being the climatically diversed country, there is diversity in the flora and fauna of different parts of the country. Atmospheric surveys carried out in different parts of India reveal that, Alanus nitida, Amarantus spinosus, Argemone mexicana Cocos nucifera, Betula utilis, Borasus flabellifer, Caraica papaya, Cedrus deodara, Cassia fistula, Parthenium, Chenopodium album, Dodonaea viscosa, Malotus phillipensis, Plantago ovata, Prosopis juliflora, Ricinus communis, Holoptelea intergifolia are the allergenically important pollens of the country. Among the fungal aeroallergens, Alternaria, Candida aibieans, Aspergillus versicolor, Aspergillus terreus, Aspergillus japonicus, Cladosporium cladosporoides, Fusarium roseum, Ganoderma lucidum,Neurospora sitophila Helminthosporium, Ustilago trtici, Uromyses are important allergens. Dust mites D. farinae, D.pteronyssinus are also important source of inhalant allergens particularly in the coastal areas of the country. Cockroaches, beetles, weevils, mosquitoes, house flies also contribute towards the aeroallergen load and are allergenically implicated. Avoidance of the indoor and outdoor aeroallergens is recommended for better management of respiratory allergy.