Genetic Biomarker May Predict Severity of Food Allergy

Researchers from Ann & Robert H. Lurie Children’s Hospital of Chicago and colleagues reported for the first time that a genetic biomarker may be able to help predict the severity of food allergy reactions. 

Currently there is no reliable or readily available clinical biomarker that accurately distinguishes patients with food allergies who are at risk for severe life-threatening reactions versus more mild symptoms. Findings were published in the Journal of Allergy and Clinical Immunology.

Dr. Lang and colleagues found that the presence of an enzyme isoform called α-tryptase, which is encoded by the TPSAB1 gene, correlates with increased prevalence of anaphylaxis or severe reaction to food as compared to subjects without any α-tryptase.

“Determining whether or not a patient with food allergies has α-tryptase can easily be done in clinical practice using a commercially available test to perform genetic sequencing from cheek swabs,” said lead author Abigail Lang, MD, MSc, attending physician and researcher at Lurie Children’s and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine. 

Tryptase is found mainly in mast cells, which are white blood cells that are part of the immune system. Mast cells become activated during allergic reactions. Increased TPSAB1 copy number which leads to increased α-tryptase is already known to be associated with severe reactions in adults with Hymenoptera venom allergy (or anaphylaxis following a bee sting).

Dr. Lang’s study included 119 participants who underwent TPSAB1 genotyping, 82 from an observational food allergy cohort at the National Institute of Allergy and Infectious Diseases (NIAID) and 37 from a cohort of children who reacted to peanut oral food challenge at Lurie Children’s.


Abigail Lang, Stephanie Kubala, Megan C. Grieco, Allyson Mateja, Jacqueline Pongracic, Yihui Liu, Pamela A. Frischmeyer-Guerrerio, Rajesh Kumar, Jonathan J. Lyons. Severe food allergy reactions are associated with α-tryptase. Journal of Allergy and Clinical Immunology, 2023; DOI: 10.1016/j.jaci.2023.07.014

Ann & Robert H. Lurie Children’s Hospital of Chicago. (2023, September 20). Genetic biomarker may predict severity of food allergy. ScienceDaily. Retrieved September 22, 2023 from

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