Bullous Pemphigoid, Mucous Membrane Pemphigoid and Pemphigus Vulgaris: An Update on Pathobiology

Pemphigoid and pemphigus vulgaris (PV) are autoimmune diseases that cause potentially debilitating erosions and blistering of the skin and/or mucous membranes. In bullous pemphigoid (BP), autoantibodies target components of the basement membrane zone (BMZ), most importantly the hemidesmosomal proteins, BP180 and BP230. Research efforts have uncovered some of the complex mechanisms that cause this disease, including the interplay between the humoral and cell-mediated immune responses, as well as the role of complement activation, inflammatory cell activation, and proteolytic enzymes. In mucous membrane pemphigoid, which preferentially targets mucous membranes, several antigenic targets along the BMZ have been identified. In PV, desmoglein autoantibodies play the most critical role in the disease, with various other target antigens acting adjunctively to exacerbate the disease by apoptotic signaling. The relationship between apoptosis and acanthosis has yet to be clearly defined, but they may promote each other to enhance disease activity. This article provides an update on the pathogenesis of these diseases.