A team of scientists from the UK’s Medical Research Council (MRC) has developed what is known as a mast activation test (MAT) to safely and accurately diagnose peanut allergies.
The new blood test avoids the risk of false-positives or allergic reactions, including anaphylactic shock.
It is claimed to be five times more cost-effective than the standard food allergy test, oral food challenge (OFC), and could be used to test for other food allergies.
MRC clinician scientist and the study lead author Dr Alexandra Santos said: “The current tests are not ideal.
“If we relied on them alone, we’d be overdiagnosing food allergies, only 22% of school-aged children in the UK with a positive test to peanuts are actually allergic when they’re fed the food in a monitored setting.
“The new test is specific in confirming the diagnosis so when it’s positive, we can be very sure it means allergy. We would reduce by two-thirds the number of expensive, stressful oral food challenges conducted, as well as saving children from experiencing allergic reactions.”
Currently, skin-prick or specific immunoglobulin E (IgE) tests are used by doctors to diagnose peanut allergy. However, these tests could lead to over-diagnosis or false-positives and they cannot differentiate between sensitivity and true food allergy.
According to the MRC researchers, MAT could act as a second line tool when skin-prick test results are inconclusive and before referring children and their families to undergo an OFC.
MAT targets the mast cells, which play a crucial role in causing allergic reactions.
It was developed on the basis of an allergy testing that involved the use of blood samples from 174 children, with 73 of these having peanut allergies and 101 being tolerant.
During the test, scientists added peanut protein to mast cells to screen for IgE-mediated activation and found that MAT accurately identified peanut allergy with 98% specificity.
Researchers also observed that the test reflected the severity of peanut allergies.