Investigating potential biomarkers for food allergy

photo: Marta Branco on Pexels

It is still unknown why some people have allergic reactions to certain foods and others don’t. New research by Associate Professor Katrina Randall hopes to identify if certain types of T-follicular cells – cells that are part of the immune system and can help B cells make antibodies - play a role in a person’s allergic response.

Building on a recent discovery by ANU researchers about a protein called neuritin, which helps prevent the body from making IgE or allergy antibodies, Dr Randall has been awarded a grant by AIFA to run a pilot trial to quantify the levels of T follicular cells and their levels of neuritin in people with allergies to see if they are biomarkers of clinical allergic reactions.

“The idea for this study came about from my interest in a rare immunodeficiency that arises due to the loss of DOCK8 protein, as my PhD work described the mouse model of this disease.”

“Further work by others in the field has recently identified an increase in a subtype of T-follicular helper cells in people who have this disorder, which is also characterised by an increased frequency of allergic reactions, and also in people with allergy who don’t carry the DOCK8 mutation.”

“Given that there is evidence that the types of T-follicular cells that you have is associated with risk of allergic disease and knowing that neuritin is also present in T-follicular cells, we’re now investigating blood samples from people with allergy antibodies -  both those that get allergic reactions due to these antibodies and those that have the allergy antibodies but don’t get allergic disease - to see if the types of T-follicular cells you have, or their neuritin levels, contribute to the severity of a person’s allergy.”

Blood tests and skin prick tests are only able to determine if a person has allergy antibodies, but can’t definitively say whether this will result in an allergic reaction. Currently, food challenges - where an individual has to ingest the suspected allergen - is the only way to determine if someone is allergic to a food.

If the trial is successful in showing that neuritin levels or the types of follicular helper cells present are biomarkers, the findings could help predict the chance of a clinical allergic reaction in the future in those people who have allergy antibodies to a food but have never eaten it.