The Process of Remission from Peanut Allergy Mapped Out

Credit: NIH

An Australian study published in Allergy, has identified the key immunological changes that support the remission of peanut allergy in children, a discovery that could pave the way to new, more targeted treatments.

The research showed, for the first-time, that specific gene networks are rewired to drive the transition from peanut allergy to clinical remission following a combination treatment of a probiotic and peanut oral immunotherapy.

The study found that this network reprogramming essentially shuts down the allergic immune response that was responsible for causing a food allergy.

Lead researcher, Professor Mimi Tang of Murdoch Children’s Research Institute, said this was the first study to map the complex gene to gene communication and connectivity underlying clinical remission of peanut allergy.

“The immunological changes leading to remission of peanut allergy were largely unknown,” she said. Previous studies had mostly focused on examining the levels of gene expression, without also exploring how genes interact with each other. But genes don’t work in isolation; instead, biological responses are controlled by large numbers of genes communicating with each other, so it made sense to look at these interactions more closely.

“What we found was profound differences in network connectivity patterns between children who were allergic and those who were in remission. These same changes were also seen when we compared gene networks before and after immunotherapy in the children who achieved remission following immunotherapy.”

The randomised controlled trial involved 62 peanut allergic children, ages 1–10, who received a combination treatment of a probiotic and oral immunotherapy (gradual introduction of the allergen) or a placebo. Following 18 months of treatment, 74% taking the combination treatment achieved remission compared with 4% in the placebo group.

The peanut oral immunotherapy that was used in combination with the probiotic in the trial was PRT120, a lead candidate from biotech company Prota Therapeutics.

The team led by Professor Tang also recently showed in a separate trial that two treatments — the combination probiotic and peanut oral immunotherapy treatment and the peanut oral immunotherapy alone — were highly effective at inducing remission and desensitisation. About half of the treated children achieved remission, which allowed them to stop treatment and safely eat peanut freely.

Murdoch Children’s Dr Sarah Ashley said while oral immunotherapy could successfully induce desensitisation and remission, desensitisation often waned after treatment ended or even during ongoing maintenance dosing.

“Certain changes in the allergen-specific immune cells, called Th2 cells, are critical to achieving lasting remission,” she said. Th2 cells are essential for generating allergen-specific antibodies and the development of food allergy. We found that the Th2 signalling that drives allergy is ‘turned off’ in children in remission.”

Food allergy is a global public health concern, affecting 10% of infants and 5–8% of children.

Source: Murdoch Children’s Research Institute