Luxembourg population-based study shows 42% have allergies, age group 25-34 most affected

The research of the Molecular and Translational Allergology Group at the Luxembourg Institute of Health (LIH) that Hilger leads together with Annette Kuehn also studies how allergies affect people in Luxembourg: In collaboration with the Department of Precision Health (LIH), they published a national population-based study where they found that 42.6% of adult participants had a physician-diagnosed allergy and an astonishing 44% tested positive for IgE antibodies, which is seen as a marker indicating allergic sensitisation.

“Importantly, the study showed that the youngest participants, meaning adults that were 25-34 years old, had the highest allergy burden and the highest need for medical care. This study is the first to provide data on the national level, and it shows that there is an urgent need for better allergy diagnosis and treatment in order to prevent worsening of symptoms and multi-organ involvement. Early diagnosis is an important pillar of allergic disease prevention strategies, but epidemiological data on allergic sensitization in children are currently lacking in Luxembourg.”

Advances in allergy research enabling new insights

Much has happened in the field of allergies in the last three decades, the most important development being the characterisation of allergenic molecules from many sources. This generated a vast field for fundamental research and many opportunities for improvement of patient in vitro diagnosis.

“The availability of well-defined allergen molecules, together with advances in molecular biology, biotechnology and health technology have substantially changed diagnosis and treatment of allergic diseases, allowing for a better endotyping of patients, resulting in a personalised care.”

“The second very important development was the formulation of the epithelial barrier hypothesis, ‘which proposes that the increase in epithelial barrier-damaging agents linked to industrialization, urbanization and modern life underlies the rise in allergic, autoimmune and other chronic conditions’ (C. Akdis; Nat Rev Immunol 2021). These new insights allow to design adequate prevention and treatment strategies for chronic inflammatory diseases, including allergy.”

Recent research has also found a link between immune-mediated diseases and climate change, due to the associated increase in environmental factors impacting the human immune system.

The team was able to validate those allergens in national and international clinical collaborations and many of them are now available for molecular IgE-diagnosis, which has helped improve allergy diagnosis of patients and personalised dietary advice.

Research highlight: Discovering people with fish allergy are able to add particular fish to diet

Fish is a highly valued nutritional food, but it is also among the most common foods that elicitate IgE-mediated food allergy. The general understanding used to be that people with a fish allergy have to avoid all types of fish, which of course restricts nutritional intake options. Kuehn, Hilger and team discovered that there is in fact a fish tolerable for these patients.

“Using our portfolio of purified fish allergens for in vitro diagnosis, and in collaboration with the Centre Hospitalier de Luxembourg (CHL), we showed that most patients were able to tolerate thornback ray, a cartilaginous fish.”

“In a subsequent large multicentre study involving 263 patients from 6 countries, we could confirm our findings, demonstrating that using multiplex IgE testing in fish-allergy diagnosis will drastically reduce the number of required food challenges and help identify tolerated fish for each patient, thereby avoiding unnecessary dietary restrictions.”

Putting Luxembourg on the allergy research map

The work of the group led by Christiane Hilger and Annette Kuehn has gained high visibility at the international level.

“The research of A. Kuehn and myself had a significant impact on patient diagnosis by elucidating allergen sources, providing recombinant molecules for diagnosis and contributing to the education of the medical community by joining international boards and task forces.”

Hilger is a board member of the WHO/IUIS Allergen Nomenclature Sub-Committee, she was elected board member of the Interest Group of Allergy Diagnosis and Systems Medicine (IGADSM) of the European Academy of Allergy and Clinical Immunology (EAACI) in 2017, followed by being elected as secretary in 2019 and as chair in September 2021.

Kuehn and Hilger both substantially contributed to the first comprehensive handbook on molecular allergology available to the clinical and research community. The “Molecular Allergology User’s Guide” was originally published in 2016 with an updated version edited and launched in 2022 by Hilger, together with four internationally renowned scientists.It is freely available as book and supplement of the journal Pediatric Allergy and Immunology (PAI).

“In my role as Chair of the IGADSM, I initiated a new international task force on Molecular Allergology in 2023. The objective of this task force is the promotion of molecular diagnosis by compiling a pocket guide with key information and clinical decision algorithms for daily clinical practice.”