Passive Cutaneous Anaphylaxis Protocol
Local cutaneous anaphylaxis is a type I hypersensitivity reaction mediated by the cross-linking of antigens to immunoglobulin E (IgE) on the surface of mast cells and basophils. Quantification of these allergic responses can be achieved by using Evans Blue dye to measure changes in vascular permeability after antigen challenge. In passive cutaneous anaphylaxis (PCA), an exogenous IgE antibody specific against an antigen (e.g., 2,4-dinitrophenol) is injected intradermally in the ear. Several hours later the antigen is injected intravenously along with Evans blue dye to measure plasma extravasation.
PCA MODEL INDUCTION
The photo on the left is the control site, and the photo on right is the test site of induction. Challenge occurs 24-hr after induction. Photos were taken 40 minutes post challenge, and study-dependent endpoints are assessed as required.
- PK/PD blood collections
- Ear thickness measurements
- Cytokine/chemokine analysis
- Clinical chemistry
- Histopathological evaluation