Exploring the effectiveness of Itulazax on birch-related food allergy in adults treated with Itulazax for birch pollen allergy

Pollen from the birchtree, as well as other related trees of the Betulaceae and
Fagaceae family, are the most dominant treepollen in Northern and Central
Europe and cause a wide range of allergic complaints such as rhinitis and
asthmatic symptoms (T. Biedermann, et. al. , 2019). In the general European
population, the prevalence of birch pollen sensitization ranges from about 8%
to 16%. Several European data indicate that birch pollen are responsible for a
large percentage of sensitization among tree-allergic patients in Europe, with
Bet v 1 as the main allergen (T. Biedermann, et. al., 2019).

In addition to rhinitis and asthmatic symptoms, patients with a birch pollen
allergy also frequently experience IgE-mediated food allergies. These reactions
are caused by IgE cross-reactivity between the birch pollen allergen Bet v 1
and its homologues in foods and is also known as pollen-food-syndrome. About
70% of birch pollen-allergic patients have allergic complaints to various foods
(usually fruits, vegetables and nuts) in the context of such a
pollen-food-syndrome (M. Geroldinger-Simic, et. al., 2011 ; N. Eriksson, et
al., 1982).

Symptoms of pollen-food-syndrome mainly consist of mild local reactions such as
itching and/or tingling of the lips, tongue and/or throat. More serious
complaints such as swelling of the throat may occur. In addition, patients may
also experience systemic reactions such as urticaria, rhinitis or anaphylaxis.
Although it can generally be assumed that severe systemic reactions occur less
frequently in pollen-related food allergies, it should be borne in mind that
they do occur (J. Klein-Tebbe, et. al., 2002). Because the allergens that cause
the pollen-related food allergy are labile proteins, which are not resistant to
heating, for example, processed (e.g. cooked) foods cause fewer complaints than
raw foods.

At the Allergology outpatient clinic in the UMC Utrecht, patients with allergic
rhinitis to tree pollen are noted to also have food allergies, especially to
fruit, vegetables and/or nuts. What is striking is that some patients who
receive immunotherapy for birch pollen, eventually experience fewer complaints
from certain foods. Both during and after the therapy it has been noted that
some patients can eat these products again without any complaints.

The primary aim of this study is to investigate whether sublingual treepollen
immunotherapy with Itulazax has an effect on food allergy-related quality of
life in adults with tree pollen allergic rhinitis who also have a food allergy
in the context of pollen-food-syndrome.

The secondary aim of this study is to investigate whether treatment with
Itulazax in this patient group has an effect on the severity and threshold of
food allergy, tolerance to raw foods, level of specific IgE and size of the
skin test.

Prospective cohort study assessing whether the use of Itulazax in adults with
allergic rhinitis has an effect on food-allergic complaints in the context of
pollen-food-syndrome in the outpatient clinic of UMC Utrecht. The Itulazax will
be prescribed in routine care to patients with allergic rhinitis to tree pollen
who qualify according to the current guideline.

Inclusion of patients will take place in 2022 to 2024. The minimum follow-up
period for patients is 3 years after the start of the study, so it runs until
at least 2027.

The treatment with Itulazax will most likely have a positive effect on the
patient's hay fever symptoms with the tree pollen, which is also the reason why
this treatment has been prescribed (in the context of regular care). Itulazax
could also have a positive effect on food allergy symptoms, but this is not
certain. That is why this research is being conducted.
If the patient participates in this study, insight is provided into the course
of the food-allergic complaints at the time of treatment with Itulazax. This
drug could possibly be given in the future as a treatment for patients with
pollen-food-syndrome.
The burden of the research do not outweigh the positive effects of the therapy
with Itulazax.