Not all grasses pack the same allergenic punch

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New research reveals a potential link between pollen from certain grass species and respiratory health issues such as asthma and hay fever.

The research, which brings together health care data and ground-breaking ecological techniques, could set a roadmap for refining pollen forecasts and assist the 400 million people worldwide with allergic rhinitis and more than 300 million asthmatics.

Current pollen forecasts rely on measuring the total load of grass pollen in the atmosphere but don’t distinguish between pollen from different types of grass, says Nicholas Osborne, associate professor at the University of Queensland.

“Pollen forecasts are crucial for people with allergic asthma or hay fever to manage their symptoms,” Osborne says.

“While most people manage their asthma very well, increased exposure to pollen may increase the risk of hospitalization due to asthma exacerbation,” he says. “The ability to predict when allergic pollen is in high amounts over population centers allows us to warn people when the risk is highest.”

The research is the first project to use an ecological biomonitoring method called eDNA (environmental DNA) to explore the relationships between airborne pollen and human health.

“We have suspicions that different types of grass may be more allergenic than others, as we see in thunderstorm asthma with the assumed effect of rye grass, but this has yet to be examined more closely,” Osborne says.

“Native species and grasses common in the north of Australia appear to be less allergenic than temperate introduced species in the south, but this has not been measured in detail. The new technology of eDNA measurement has allowed us for the first time to examine grass pollen at the genus and species level and link that back to hospital and medication use.”

University of Exeter’s Francis Rowney, who undertook the health data portion of the work, says it was fascinating to find that particular grass species may have greater impacts on respiratory health than others.

“Proteins in the pollen are what trigger allergic reactions, and there are common allergenic proteins between some grass species,” Rowney says.

“We need to better understand the molecular basis of the allergens and allergic reactions to further investigate which are the most allergenic species, and whether there are differences in reactions between different people.”

This research is published in Current Biology.

The investigation was part of the larger Natural Environment Research Council-funded PollerGEN research project, which in 2019 established the use of eDNA techniques to identify different types of microscopic grass pollen grains.

Source: University of Queensland