A new study was published in Nature Communications earlier this month that could help people with peanut allergies. Researchers have identified six genes that are responsible for activating hundreds of other genes in children who experience allergic reactions to peanuts. These findings may help scientists to better understand how peanut allergy actually works.
Prevalence of Peanut Allergy in Children
Children tend to have food allergy issues more frequently than adults. As of 2015, 4.2 million children in the United States have food allergies, with peanut being the most common allergen (with milk and shellfish following closely behind).
Not only is peanut allergy the most common among children, but it is also a growing health concern in the United States. Between 1999 and 2010, the prevalence of peanut allergy in children rose from an estimated .04 percent to 2 percent.
Today’s standard treatment for those with peanut allergy includes avoidance of peanuts along with precise care in the event of an allergic reaction. According to Supinda Bunyavanich, Mount Sinai associate professor in pediatrics, genetics and genomic sciences and senior author of the study, “This study highlights genes and molecular processes that could be targets for new therapies to treat peanut-allergy reactions and could be important to understanding how peanut allergy works overall.”
A Groundbreaking Discovery
This pivotal study was led by Icahn School of Medicine at Mount Sinai in New York, New York, and was the first to study gene expression in children throughout the duration of their allergic reactions. This allowed each subject’s reaction to be compared to his or her individual pre-reaction state.
A double-blind placebo controlled human trial was led by researchers, who collected and analyzed blood samples from 40 children with peanut allergy. Double-blind means that neither the clinicians who administered the doses nor the participants knew which were peanut and which were placebo. In this case, the placebo was oat powder. Subjects were given peanut in incremental amounts at 20 minute intervals until an allergic reaction occurred or the subject ingested a cumulative dose of 1.044 grams of peanut. Blood samples were drawn before, during and after the challenge. Each child received peanut and placebo doses on different days.
The team performed RNA sequencing on the samples to determine which genes and which cells were active during allergic reactions, thus discovering which genes and cells were the most likely to be driving the allergies.
During the course of the study, the researchers identified six genes as key components that are active during a peanut allergy response: LTB4R, PADI4, IL1R2, PPP1R3D, KLHL2 and ECHDC3.
This study is unique in that it offers a clearer picture of what goes on during a peanut allergy reaction. In some studies, genes in individuals with food allergies have been compared to those without them, but not necessarily during an allergic response. In this study by researchers at Icahn School of Medicine, the genes expressed over time in children who were actively reacting to peanut were examined, offering a detailed picture of what was happening on both the genetic and molecular level during the peanut allergy reaction.
The trial was then repeated with 21 other patients with peanut allergy and the results were the same.
“We still don’t completely understand everything that happens in the body during peanut-allergy reactions,” says Professor Supinda Bunyavanich. “We can use these genes to direct our studies of peanut allergy and hopefully predict how strongly someone with peanut allergy will react.”
The research team does not plan to stop with peanut allergy. Future studies are on the radar that target other common allergens such as egg and milk to determine if their findings are similar to other types of food allergy.