It would help to have a diagnostic test specifically for peanut allergies that is reliable and determines the potential severity of a person’s allergic response.
That is what chemists at the University of Connecticut (UConn) are working on. The test they are developing is significantly more sensitive than current testing methods and requires only a few drops of the patient’s blood.
Roles of IgE and Histamine
The new PA test capitalizes on the way allergic reactions to peanuts happen:
- After an allergic individual ingests peanut, their immune system releases the antibody called IgE or immunoglobulin E.
- The IgE antibodies bind with peanut allergen molecules to flush them out of the body.
- As IgE is released, tissue cells in the body manufacture histamine. As more antibodies are released, more histamine is produced. Histamine is responsible for allergy symptoms.
“Our theory is that the level of those antibodies can be used to predict how severe a patient’s allergy is at any one point in time,” said researcher and UConn Professor James Rusling.
The scientists tested their theory by:
- Floating blood serum from allergic patients over a sample array of peanut allergen components – a protein peptide and carbohydrate residue.
- IgE antibodies in the serum were pulled down by the allergen components in the array samples and bound to them.
- The quantity of antibodies bound to the allergen components was measured. Higher antibody levels indicated a more severe allergic response was likely.
The research results correlated well with the participating individuals’ results from standard tests.
“Eventually, we’d like to use maybe five different peptides and carbohydrate samples to see how these IgEs bind to them,” Rusling said. “That way, we could determine a clear finger print of a patient’s susceptibility to a specific allergen.”
Preventing PA Misdiagnosis
The current method of testing for peanut allergies measures antibody levels using a mixture of all the peanut proteins, not specific ones. Some of the molecules in the all-protein mixture can lead to a misdiagnosis. People may be diagnosed allergic when they are not or not allergic when they are.
Though the new UConn allergy test is just out of the starting gate and requires further development, it may someday eliminate misdiagnoses by testing with arrays of specific peanut components.
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