Immunohistochemical examination of P-cadherin in bullous and acantholytic skin diseases.

Autoimmune blistering diseases (pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, dermatitis herpetiformis) and certain genodermatoses with acantholysis (Darier-disease, Hailey-Hailey disease) have different aetiological factors, but all result in bulla formation and/or in acantholysis. Cadherins are Ca++-dependent cell-cell adhesion molecules which play an important role in the cellular connection between normal cells. P-cadherin is involved in the selective adhesion of epidermal cells, and is expressed only on the surfaces of the two basal layers. We examined the expression of P-cadherin in some autoimmune bullous skin diseases and Darier's disease using immunohistochemistry and found P-cadherin to be strongly upregulated. We believe the upregulation is compensatory to the primary pathophysiological events in the various bullous dermatoses.