Antibody levels can predict resolved peanut allergies

Australian researchers, led by the Murdoch Children’s Research Institute (MCRI), have discovered how changes in antibody levels over time can predict which children are likely to outgrow their peanut allergy. Their research, published in the journal Allergy, is believed to be the first to use antibodies as biomarkers to identify persistent or naturally resolved peanut allergy in children during the first 10 years of life.

The study involved 156 infants in Melbourne with challenge-confirmed peanut allergy who were followed up at ages four, six and 10 years with questionnaires, skin prick tests, blood tests and oral food challenges. Peanut allergy naturally resolved in a third of children by 10 years, with nearly all who outgrew it doing so by age four to six.

A rise or drop in the levels of two antibodies (sIgG₄ and sIgE) that respond to peanut allergens was key to determining allergy resolution, with changes in the blood test levels of these two antibodies detected in those children who naturally outgrew their allergy. Antibody levels measured at diagnosis did not predict who would outgrow their peanut allergy, but changes in these levels over time revealed who was more likely to do so.

“Little was known before this research about whether antibodies could be used as biomarkers of naturally resolving peanut allergy during the primary school years,” said MCRI researcher Kayla Parker.

“We found the longitudinal changes were more useful in predicting those children on the path to peanut allergy resolution than relying on a single snapshot at one time point.”

Parker said the findings would help clinicians to better identify which children were likely to have an ongoing peanut allergy. She added that a regular review of children with a peanut allergy by their allergist was important to ensure they receive the most appropriate clinical care.

“Children allergic to peanut who have decreasing antibody markers may benefit from additional visits with their allergist to determine the right time for follow-up food challenges to confirm if their peanut allergy has resolved,” she said.

“Those with high or increasing levels of these biomarkers are less likely to spontaneously outgrow their peanut allergy and could be prioritised for potential early treatment options if available.

“Currently there is no routinely available treatment for peanut allergy and children should maintain strict peanut allergen avoidance; however, innovative treatment options are available through clinical trials, which are listed on the National Allergy Centre of Excellence’s (NACE) Allergy Studies Directory.”

The news comes as another new study led by MCRI found allergic diseases continue to be a significant public health burden in Australian children, with allergies affecting 40% of primary school-aged children, one-third having multiple allergies and 45% of infants with a food allergy having persistent symptoms to age 10. MCRI Associate Professor Rachel Peters said the research, published in The Journal of Allergy and Clinical Immunology: In Practice, highlighted the importance of prevention and treatment strategies, particularly for nut allergies.

“Understanding how allergy prevalence varies across the school years has important implications on informing the burden of disease, allocating healthcare resources and improving school and workforce planning,” she said.

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