Passive cutaneous anaphylaxis (PCA) is an immediate dermal response to an allergen-IgE interaction and is characterized by increased permeability of vessels within the skin. To visualize and quantify the increased permeability characteristic of PCA, the intravenous injection of Evans blue, a dye that binds to and is extravated with plasma albumin, is utilized. PCA can be used as a tool to study sensitivity to allergens and compound efficacy in ameliorating these responses.
Preclinical Drug Efficacy Studies
One ear of the animal is injected with Anti-DNP-IgE, and the other is left alone. 1-hour post-dosing animals are given a tail vein injection of Evan’s blue dye followed by a second tail vein injection of DNP-HSA. Signs of blue reaction and swelling are noted. 1-hour after the last injection, mice are euthanized and ear punch biopsies from both ears are harvested to quantify Evanâ€™s blue content in the ear tissue. The administration of therapeutic compounds is performed according to the schedule set-forth in the study protocol.
Clinical observations, body weight, quantification of PCA (Evan’s blue dye spectroanalysis), and cytokine profiling using ELISA and Luminex multiplex assays
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