Ascia‐p61: Taking Advantage of Tolerance Tests in the Mouse Model to Screen Alternative Microprojection Patch Designs for Allergy Immunotherapy

Abstract

Method: The ASCIA Action Plan for Anaphylaxis has recently been updated based on evidence-based best practice, recent coronial inquiry recommendations and extensive feedback from ASCIA membership. To ensure accuracy and consistency of information, ASCIA anaphylaxis management guidelines have also been updated. Changes to ASCIA Action PlansThe main changes are:• Key messages have been simplified and highlighted in larger font.• Greater emphasis on the positioning of the patient, using images to reinforce instructions and assist people with limited English.• The adrenaline autoinjector should always be given first, followed by asthma reliever medications if someone with known asthma and allergy to food, insects or medication has sudden breathing difficulty, even if there are no skin symptoms.• For tick allergy, reference to freeze-drying ticks before removal has been included. Conclusion:Patient outcomes can be improved by ensuring that acute management of anaphylaxis is consistent with ASCIA Action Plans. In an anaphylaxis emergency, ASCIA Action Plans provide a "how and when to give the adrenaline autoinjector" guide. It is therefore essential that all patients prescribed an adrenaline autoinjector are provided with an ASCIA Action Plan for Anaphylaxis that has been completed by a medical practitioner. Background: Allergy immunotherapy is currently a costly, prolonged process, requiring approximately 100 injections over 5 years and can lead to local or systemic side effects. Some of these drawbacks can be overcome by alternative routes such as intradermal or epicutaneous desensitisation. Here, we present a novel cutaneous delivery device, a microprojection array (MPA) which has been previously used in skinbased vaccination, as a means to overcome some of the challenges of cutaneous administration. MPAs are an array of coated projections that pierce the skin, delivering substances into the skin strata. A challenge of these devices is that they generate imflammation when applied to the skin, which may be detrimental for allergen desensitisation and therefore a new design is required. However, time taken for desensitisation in the mouse model can be significant. Using tolerance tests can reduce such time by replicating the immune response of desensitisation within days instead of weeks. Here, we hypothesised that an accelerated tolerance test can be used to screen a range of MPA designs for allergy immunotherapy potential. ASCIA-P61 TAKING ADVANTAGE OF TOLERANCE TESTS IN THE MOUSE MODEL TO SCREEN ALTERNATIVE MICROPROJECTION PATCH DESIGNS FOR ALLERGY IMMUNOTHERAPYMethods: MPA conditions for epidermal targeting were tested using florescent markers and assessed by histology. For tolerance tests, BALB/c mice were exposed daily to ovalbumin (OVA) through MPAs for eight days, followed by an induced sensitisation challenge intraperitoneally. Sensitisation prevention was assessed by eosinophil proliferation in bronchial lavage fluid and OVA-specific IgE in sera.Results: MPA designs induced a high sensitisation responses, i...