Comparative histology and immunohistochemistry of porcine versus human skin

BACKGROUND: Porcine skin is increasingly being employed as a model of human skin in various research fields, including pharmacology, toxicology and immunology, with particular interest in percutaneous permeation and organ transplantation. Porcine skin shows several anatomical and physiological similarities, but also some differences, with human skin, but few in depth comparative studies are so far available. OBJECTIVES: To study the immunohistochemical properties of normal porcine skin in comparison with human skin. MATERIALS AND METHODS: We performed a histological and immunohistochemical study on frozen and formalin-fixed, paraffin-embedded skin biopsies from domestic swine and normal human skin, using a panel of 93 monoclonal or polyclonal antibodies recognizing various human and porcine skin cell types or structures. RESULTS: We found that several antibodies used to detect normal human skin cells showed equivalent immunoreactivity on normal porcine skin. However, some antibodies commonly used to detect human skin antigens remained unreactive on porcine skin. CONCLUSIONS: Our findings highlight the main immunohistochemical properties of porcine skin in comparison with those of human skin and provide a morphological and immunohistochemical basis useful to researchers using porcine skin.