Absence of intercellular antigens in the deep layers of the epidermis in pemphigus foliaceus.

12 patients with pemphigus foliaceus, a form of pemphigus with lesions that arise in the intercellular substance in the superficial layers of the epidermis, and 7 patients with pemphigus vulgaris, where lesions are in the deep layers, were studied by immunofluorescence. Circulating antibodies to intercellular antigens (IC antibodies) were found in 11 pemphigus foliaceus and 5 pemphigus vulgaris patients. On direct immunofluorescence of skin lesions 75% (9 of 12), pemphigus foliaceus patients had intercellular deposits of IgG localized solely or predominantly in the superficial epidermal layers, whereas this was not the case in any of the patients with pemphigus vulgaris. Over 70% of the pemphigus foliaceus patients with predominantly superficial IgG deposits lacked in their lesions normal intercellular antigens usually expressed in the deep layers of the epidermis. This was shown by the inability of IC antibodies in autologous or allogeneic sera to bind to intercellular antigens in the lower epidermis of patient's skin, even though the same sera could bind to intercellular antigens in all layers of normal allogeneic skin. Lack of normal intercellular antigens deep in the epidermis may result in circulating IC antibodies binding to the superficial layers, a site which corresponds to, and thus in some patients may account for, the anatomical location of lesions in pemphigus foliaceus.