A novel painless and reliable allergy test
Date:
March 21, 2022
Source:
University of Bern
Summary:
Although allergies are widespread, their diagnosis is complex
and, depending on the type of allergy, the prospects of success
with therapy are not always clear. Skin tests so far have been
unpleasant, time- consuming and associated with a certain risk of
triggering an allergic overreaction. Researchers have now developed
a novel test that massively simplifies the diagnosis of allergies
and can reliably predict the success of a therapy.
FULL STORY ========================================================================== Although allergies are widespread, their diagnosis is complex and,
depending on the type of allergy, the prospects of success with
therapy are not always clear. Skin tests so far have been unpleasant, time-consuming and associated with a certain risk of triggering
an allergic overreaction. Researchers at the University of Bern and Inselspital, Bern University Hospital, have now developed a novel test
that massively simplifies the diagnosis of allergies and can reliably
predict the success of a therapy.
========================================================================== Approximately one third of the world's population suffers from one or
more allergies, with the trend increasing every year. By far the most widespread form of allergy is the so-called type I allergy, also known
as immediate-type allergy. This includes, for example, allergic rhinitis
(hay fever), allergic asthma, food allergies, or allergies against insect venoms, pollen, grasses or house dust mites. It is an overreaction of
the immune system to actually harmless foreign components (allergens),
which typically occurs within seconds or minutes of contact with the
allergen. Allergic symptoms can range from redness and swelling of the
skin, itching or shortness of breath to anaphylactic shock and death.
Diagnosing an allergy is complex: In addition to the medical history (anamnesis), test parameters of often unclear diagnostic value are
taken into account and patients undergo skin tests. Such skin tests are unpleasant, at times painful, time-consuming and associated with a certain
risk of triggering an allergic overreaction. Allergies are treated with
symptom control, in severe cases also with immunotherapy. This involves injecting doses of an allergen in increasing concentrations under
the patient's skin over a period of up to five years, with the aim of desensitizing the patient to the allergen. Immunotherapy is not always successful: At present, there is no reliable method for predicting the
chances of success before concluding such therapy.
A research group led by Alexander Eggel from the Department for
BioMedical Research (DBMR) at the University of Bern and the Department
of Rheumatology and Immunology, Inselspital, Bern University Hospital,
together with Thomas Kaufmann from the Institute of Pharmacology at the University of Bern, has now developed an allergy test that, on the one
hand, greatly simplifies diagnosis and, on the other hand, can reliably
predict the success of immunotherapy. The test was recently presented
in a publication of the Journal of Allergy and Clinical Immunology.
In vitro mast cells provide unprecedented reliability Type I allergy
occurs when the body produces immunoglobulin E (IgE) class antibodies
in response to allergens. The IgE antibodies are bound by IgE receptors
on the surface of specialized immune cells in the body called mast
cells. Subsequent contact with the same allergens then leads to activation
of the mast cells and therefore to the release of inflammatory mediators
such as histamine or leukotrienes, which are responsible for the allergic symptoms.
==========================================================================
For their novel allergy test, the researchers led by Alexander Eggel
and Thomas Kaufmann have developed a new in vitro cell culture which,
with the help of a few molecular biological techniques, can generate
almost any desired number of mature mast cells -- and this within a few
days. These mast cells contain IgE receptors on their surface and behave
very similarly to mast cells in the human body when they are exposed to
IgE and allergens. In the test, these mast cells are brought into contact
with blood serum from allergic individuals -- thereby binding the IgE antibodies from the serum to the cells -- and then stimulated with the allergens to be tested. At this point, the activation of the cells can
be quantified very easily and quickly using so-called flow cytometry.
"We were surprised and delighted to see that our mast cells could
be activated at almost 100 percent. To our knowledge, there are no
comparable cell lines that can be activated so well," explains Alexander
Eggel. He adds: "Another important advantage is that the test works with
serum, which is very stable and can be stored frozen for a long time,
which also allows retrospective tests and studies. In contrast, other comparable tests use whole blood, which cannot be stored and must be
processed within hours." High-throughput approach enables application on
a larger scale In order to be able to perform a large number of tests,
the researchers have developed a high-throughput approach in which
up to 36 conditions can be measured in a single test tube. This makes
possible the testing of either multiple allergens with one blood serum
or multiple sera together for the same allergen. "A trained person can
already perform about 200 tests per day using this procedure, and the
process will be further optimized," clarifies DBMR's Noemi Zba"ren,
lead author of the study.
Great potential for various applications In addition to the initial
diagnosis of allergies, the researchers hope the test will have other
major applications. "We are confident that with our test we will be
able to measure within a few months after the start of an immunotherapy
whether the therapy is effective and to what extent," says Thomas
Kaufmann. "This would be an important aid in the decision-making process
for the allergologist treating the patient, whether it makes sense to
continue the therapy or not." According to the researchers, the test
also has great potential for monitoring therapeutic success and the
duration of action for new allergy medications in clinical trials,
as well as for determining possible allergic reactions and for quality
control of food products.
And academic research should not be neglected either. "The new cell line
-- and already planned modifications to the same -- will enable us to
address many of the still unanswered questions in allergy research,"
explains Alexander Eggel.
This study was funded by the Swiss National Science Foundation SNSF and
a grant from the Swiss Innovation Agency Innosuisse.
========================================================================== Story Source: Materials provided by University_of_Bern. Note: Content
may be edited for style and length.
========================================================================== Journal Reference:
1. Noemi Zba"ren, Daniel Brigger, Daniel Bachmann, Arthur Helbling,
Lukas
Jo"rg, Michael P. Horn, Johannes M. Schmid, Hans Ju"rgen Hoffmann,
Jean- Pierre Kinet, Thomas Kaufmann, Alexander Eggel. A novel
functional mast cell assay for the detection of allergies. Journal
of Allergy and Clinical Immunology, 2022; 149 (3): 1018 DOI:
10.1016/j.jaci.2021.08.006 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/03/220321103749.htm
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