Researcher developed a new laboratory test to diagnose
peanut allergy. The test has 98 per cent specificity
and, unlike current options, it doesn't run the risk of
false-positives or causing allergic reactions such as
anaphylactic shock. The simple blood test is five times
more cost-efficient compared to the oral food challenge
(OFC) the standard food allergy test and could be
adapted to test for other food allergies. Peanut
allergies are among the most common food allergies in
children. Currently, peanut allergy using a skin-prick
test or IgE test but this may result in over-diagnosis
or false-positives and it cannot differentiate between
sensitivity and true food allergy. When skin-prick and
IgE test results are unclear, allergists rely on an OFC,
which consists of feeding peanut in incrementally larger
doses to a patient in a highly-controlled setting in
hospital to confirm allergy to the food. While the test
is the gold-standard for diagnosing food allergies,
there is risk of causing severe allergic reactions. Now,
the researchers have developed a safer, accurate blood
test in the lab. The new test, called the mast
activation test (MAT), could act as a second line tool
when skin-prick test results are inconclusive and before
referring children and their families to specialists for
an OFC. The lead researcher said that the current tests
are not ideal. The new test is specific in confirming
the diagnosis so when it's positive. It reduce by
two-thirds the number of expensive, stressful oral food
challenges conducted, as well as saving children from
experiencing allergic reactions. Food allergy symptoms
are triggered when allergens interact with an antibody
called immunoglobulin E (or IgE). The food allergens
activate IgE antibodies, triggering symptoms such as
skin reactions, itching or constricting of the mouth,
throat and airways, and digestive problems (such as
stomach cramps, nausea or vomiting). The current
skin-prick test and IgE test, which have been in use for
decades, measure the presence of IgE antibodies. The new
test focuses on mast cells, which play a crucial role in
triggering allergic reactions. Mast cells activate by
recognising the IgE in plasma and, in allergic patients,
produce biomarkers associated with allergic reactions,
which can be detected in the lab. The MAT test is five
times cheaper to conduct than the OFC, which requires an
allergist and specialist nurses on hand to monitor for
adverse reactions and provide medical support if
symptoms arise. The researchers believe the MAT test may
have other uses, for example, in the food industry to
detect the presence of allergens in products.
Pharmaceutical companies could use it to monitor
patients' allergic response to drugs being evaluated
during clinical trials. The scientists plan to
transition the biomarker test out of the laboratory and
into a clinical setting. They will be testing blood
samples from patients with suspected allergies to
further validate its utility. |