High Environmental Ozone Levels Lead to Enhanced Allergenicity of Birch Pollen

Abstract

BackgroundEvidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals.ObjectivesTo evaluate the impact of urbanisation and climate change on pollen allergenicity.MethodsCatkins were sampled from birch trees from different sites across the greater area of Munich, pollen were isolated and an urbanisation index, NO2 and ozone exposure were determined. To estimate pollen allergenicity, allergen content and pollen-associated lipid mediators were measured in aqueous pollen extracts. Immune stimulatory and modulatory capacity of pollen was assessed by neutrophil migration assays and the potential of pollen to inhibit dendritic cell interleukin-12 response. In vivo allergenicity was assessed by skin prick tests.ResultsThe study revealed ozone as a prominent environmental factor influencing the allergenicity of birch pollen. Enhanced allergenicity, as assessed in skin prick tests, was mirrored by enhanced allergen content. Beyond that, ozone induced changes in lipid composition and chemotactic and immune modulatory potential of the pollen. Higher ozone-exposed pollen was characterised by less immune modulatory but higher immune stimulatory potential.ConclusionIt is likely that future climate change along with increasing urbanisation will lead to rising ozone concentrations in the next decades. Our study indicates that ozone is a crucial factor leading to clinically relevant enhanced allergenicity of birch pollen. Thus, with increasing temperatures and increasing ozone levels, also symptoms of pollen allergic patients may increase further.

The effects of short- and long-term air pollutants on plant phenology and leaf characteristics

“…On the other hand, plants are threatened by pollution whereby different agents lead to different effects (Mudd and Kozlowski, 1975;Taylor, 1978;Gratani et al, 2000;Beck et al, 2013). Ozone (O 3 ), a secondary pollutant, is considered to affect plants severely, ranging from visible injuries to higher susceptibility to pathogens and to a reduction of plant productivity (Krupa et al, 2000;Gregg et al, 2003;Karlsson et al, 2003;Ainsworth et al, 2012).…”

Outdoor Allergens

“…40,41 Ziska and associates collected ragweed pollen along an urban transect in Maryland, using the urban environment as a surrogate for climate change. 46 The complete reference list can be found on the companion Expert Consult website at http://www.expertconsult.inkling .com. The urban ragweed grew faster with a greater above-ground biomass, flowered earlier and produced more pollen than plants in the rural site.…”

Control Process for Manufacturing and Standardization of Allergenic Molecules

“…Another important parameter is the variability of the pollen depending on climatic conditions. Temperature, humidity, position of the flowers in plants, orientation, environmental contamination, diseases, or age of the plants may also influence the allergen composition and concentration [10,11]. Keeping in mind the above detailed potential high variability, it is accepted that homogeneous lots may be generated through the mixing of lots from different years or locations [12].…”