Monday, May 28, 2018

Study finds buckwheat common allergen in horses

An allergen micro-chip developed at the Medical University of Vienna, can be used to detect allergic sensitization in horses.

"Our best friends are even more like us than we thought, and that also applies to the immune system," explains study leader Erika Jensen-Jarolim, affiliated with the Institute of Pathophysiology and Allergy Research of the MedUni Vienna and the Messerli Research Institute. The international study also involved researchers from Germany, Switzerland and Japan. 

A custom-designed allergen microarray containing 131 allergens was produced based on existing ImmunoCAP ISAC technology. Using this technique, only a drop of blood was required, even for horses.

The research team used the allergen micro-chip to test sera from 51 horses from Europe or Japan for IgE reactivity. IgE is an antibody primarily involved in repelling parasites. It is also responsible for allergic reactions and is an important biomarker for the early detection of allergies. 

Horses included in the study had a variety of clinical signs, such as insect bite hypersensitivity, chronic coughing, recurrent airway obstruction or urticaria. Some horses were clinically normal.
Horses showed individual IgE-binding patterns irrespective of their health status, indicating sensitization. 

The researchers identified a strong IgE immune response, especially to buckwheat, but also to alder pollen and bermuda grass. 

Most prevalent was the buckwheat 2S-albumin Fag e 2 allergen, found in 72.5% of the tested horses. Buckwheat has recently gained popularity in both human and horse diets.

"Buckwheat is a protein-rich pseudo-cereal very often in horse-goodies and horse muesli," explains Jensen-Jarolim. 

Interestingly, alder and Bermuda grass are not common allergens in human medicine in Europe and Japan. The researchers suggest that their frequency in horses is likely due to specific respiratory exposure around paddocks and near the ground.

The flora on paddocks will now be examined in cooperation with Uwe Berger and the team of the Pollen alarm service of the MedUni Vienna. 

"If, and how strongly, these allergens have something to do with the allergic reactions common in horses such as cough, colic and skin symptoms, must first be checked clinically" says Jensen-Jarolim.
“In any case, our results are, much like the IgE test on human allergy sufferers, a strong indication of which direction to continue to seek diagnostically."

For example, in affected horses with evidence of a buckwheat sensitization, they suggest that an allergen avoidance or elimination diet could be tried, to see if the symptoms improve.

The allergen chip is already successfully used in humans for allergy diagnosis. Similar tests are also being developed in dogs - these study results should be available soon.

For more details, see:
Molecular allergen profiling in horses by microarray reveals Fag e 2 from buckwheat as a frequent sensitizer.
L. Einhorn, G. Hofstetter, S. Brandt, E. K. Hainisch, I. Fukuda,  K. Kusano, A. Scheynius, I. Mittermann, Y. Resch-Marat, S. Vrtala, R. Valenta, E. Marti, C. Rhyner, R. Crameri, R. Satoh, R. Teshima,  A. Tanaka, H. Sato, H. Matsuda, I. Pali-Schöll, E. Jensen-Jarolim.

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