Adhesion molecules and related proteins in Darier's disease and Hailey-Hailey disease.

We have used antibodies to plakoglobin and E-cadherin: the lectins, peanut agglutinin (PNA) and soybean agglutinin (SBA); and sera from patients with the autoimmune diseases pemphigus vulgaris (PV) or pemphigus foliaceus (PF), in an immunohistological study of Darier's disease and Hailey-Hailey disease. There was normal expression of plakoglobin, E-cadherin, lectins and pemphigus antigens at the periphery of keratinocytes in uninvolved skin. Clumps of plakoglobin were detected within acantholytic cells in Hailey-Hailey disease, whereas expression was diffuse in acantholytic cells in Darier's disease. This difference may reflect differences in the pathogenesis of acantholysis. E-cadherin expression was weak or absent at the periphery of some acantholytic cells; lectin binding was sometimes reduced around acantholytic cells, and pemphigus antibodies did not bind to the acantholytic cells involved skin in either disease. Internalization, conformational changes or proteolysis may alter the expression of extracellular epitopes by acantholytic cells.