(685h) Microneedles for Cutaneous Peanut Allergen Immunotherapy

RATIONALE: Peanut allergy is a life-threatening condition. About 1% of the US population (~3 million people) has peanut allergies, and there is no FDA-approved treatment. Strict avoidance, and a peanut-free diet is the only option available to manage peanut allergies. We hypothesized that microneedles (MNs), could be used to safely deliver peanut allergen into the skin for cutaneous peanut immunotherapy.

Methods: Mice were sensitized to peanut proteins. These peanut sensitized mice were then treated with MNs coated with peanut extract. The mice were next orally challenged with peanut flour to simulate a peanut exposure. Markers of allergic reaction including anaphylactic score, serum mast cell protease 1 (MCPT-1) and serum histamine levels were quantified after oral challenge. IgE levels were also monitored.

RESULTS: Mouse model of peanut sensitization was successfully developed. MNs coated with peanut extract induced significantly higher IgG antibodies without any significant increase in IgE levels. After peanut flour oral challenge, significantly lower anaphylactic score, MCPT-1, and histamine levels in serum were observed. Splenocyte restimulation assay suggested activation of the Th1 pathway.

Conclusions: The data of this study shows that MN-based cutaneous allergy immunotherapy is able to offer protection against oral peanut challenge, and overall it is an exciting new technology that has potential to desensitize against food allergies.