Key factors to establish the ovalbumin-induced atopic dermatitis minipig model: age and body weight.

Background: Given its similar structure and immune response to the human skin, porcine is a good model for dermal studies. Here, we sensitized ovalbumin (Ova) on minipig back skin for 2-4 weeks to induce chronic atopic dermatitis (AD).

Results: Gross observation, serum cytokine level, epidermal thickness, and epidermal integrity did not change after 4 weeks of Ova induction compared with the control, indicating AD modeling failure. Only the neutrophils in the blood and macrophages in bronchoalveolar lavage fluid changed slightly until 3 or 2 weeks after Ova sensitization, respectively. The successful and failed Ova-induced AD minipig models only differ in age and body weight of the minipigs. The minipigs, 12 months old with a 30-kg median weight, had a two-fold thicker dermis than minipigs 8-10 months old, with an 18.97-kg median weight, resulting in impaired Ova permeability and immune response.

Conclusion: Age and body weight are key factors that should be considered when developing an Ova-induced AD minipig model.