What affects the severity of allergic reactions -

Ambrosia: the origin and the environment influence the aggressiveness of the pollen

More than 33 million people in Europe suffer from ragweed allergies. Even small amounts of ragweed pollen can trigger serious allergic symptoms such as asthma. Researchers now report that place of origin and environment influence pollen aggressiveness.

The origin of ragweed pollen from different geographic and climatic regions, as well as the level of pollution, can affect the severity of allergic reactions such as hay fever and asthma, according to a new study. For example, pollen from plants from different regions show different levels of aggressiveness. The study results were published in the journal Frontiers in Allergy.

Even small amounts of pollen are enough for an allergic reaction

The interuniversity study team, led by the Medical University (MedUni) of Vienna and involving the University of Vienna and the University of Natural Resources and Applied Life Sciences, developed an allergy model in which mice were exposed to pollen from ragweed plants (Ambrosia artemisiifolia) collected from different geographic regions became.

As explained in a press release, even a small amount of pollen (180 pollen grains in total) has been shown to be enough to trigger an allergic reaction, far less than the high concentrations of pollen found in the air during the winter season. seasonal flowering.

Climate change is also lengthening the flowering period in Europe and allowing the plant to spread to more northern regions. But the regional origin of the pollen also determines the severity of the allergic reaction.

Changes in aggressiveness due to environmental influences

“Our study shows that pollen from different environments can be aggressive in different ways,” says lead researcher and coordinator of the “Atopica” project, Michelle Epstein from MedUni Vienna.

"Thus, not only airborne pollen concentrations, but also intrinsic (indoor) changes related to the environment could alter the sensitizing ability of pollen and worsen allergic symptoms."

The professor involved in the study at the Department of Functional and Evolutionary Ecology at the University of Vienna, Wolfram Weckwerth, says: “We now know that the aggressiveness of pollen changes due to environmental influences. The next steps are further characterization of the pollen, particularly at the molecular level, to unequivocally identify the composition of the allergenic components.

And Anke Bellaire, who works in the Department of Structural and Functional Botany at the Institute of Botany and Biodiversity at the University of Vienna and is also one of the authors, explains that the researchers want to pursue ultrastructural subcellular analysis of pollen. ragweed for more information. characterization.

effects of climate change

According to Gerhard Karrer, professor of botany at the University of Natural Resources and Life Sciences, who was part of the team that collected the pollen in Austria, controlling ragweed is a major health concern. and an adaptation strategy to mitigate and manage the effects of climate change.

According to scientists, the influence of climate change and other environmental factors most likely includes a number of other pollen-producing plants. This applied research model now offers a strategy for further studies examining the effects of climate change on pollen allergy.

Very allergenic plant

As explained in the press release, ragweed (Ambrosia artemisiifolia) is a highly allergenic plant whose pollen can cause hay fever in sensitized people as well as asthma.

More than 33 million Europeans currently suffer from such an allergy. Researchers predict an increase to 77 million cases by 2060 due to climate change.

Ambrosia season begins in August and lasts through the fall. However, with global warming, the season will be longer and warmer temperatures will cause these plants to grow in more northern regions and at higher elevations.

A single plant can produce around a billion pollen grains per season, which can then travel thousands of miles in the wind.

These study results should pave the way for ragweed warnings and allergy prevention regulations. (ad)

Author and source information

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This text corresponds to the specifications of the specialized medical literature, medical guidelines and current studies and has been verified by health professionals.


Medical University of Vienna: Ragweed Allergy: Place of Origin and Environment Influence Pollen Aggressiveness, (Accessed: Aug 15, 2022), Medical University of Vienna Shu-Hua Liu, Sahar Kazemi, Gerhard Karrer, Anke Bellaire, Wolfram Weckwerth, Jakob Damkjaer, Oskar Hoffmann & Michelle M Epstein: Influence of environment on ragweed pollen and their sensitizing ability in a mouse model of allergic lung inflammation; in: Frontiers in Allergy, (published: 08/05/2022), Frontiers in Allergy

Important note:
This article contains general advice only and should not be used for self-diagnosis or treatment. It cannot substitute a visit to the doctor.