Bullous and cicatricial pemphigoid

Bullous pemphigoid (BP) and cicatricial pemphigoid are blistering mucocutaneous diseases characterized by detachment of the overlying epithelium from its stroma. IgG and complement components are deposited in all affected tissue at the level of blister formation--through the lamina lucida of the epithelium. The primary antibody response is of the IgG 4 subclass, and the antigens recognized by these autoantibodies have been shown to be 230 kD and 180 kD transmembrane proteins unique to the hemidesmosome of stratified squamous epithelial cells. Although it is suspected that these antigens are important in cell-substrate adhesion, this has not been proven. Stanley et al. have recently defined the sequence of a portion of the C terminal end of the 230 kD antigen and Diaz et al. have isolated a cDNA encoding for the 180 kD antigen. Structural data regarding these antigens should prove critical to definition of their presumed function. Therefore, BP is felt to be an autoimmune disease where the cutaneous lesions may solely be a consequence of binding of these antihemidesmosome autoantibodies to the specific antigen, but definitive proof of this assumption is incomplete.