Desmoglein compensation theory

Graphic depiction of the desmoglein compensation theory. The desmoglein compensation theory is a proposed explanation for the correlation between the clinical features of pemphigus vulgaris and  pemphigus foliaceus and the autoantibody profiles of these disorders. In the skin, desmoglein 1 (Dsg1) is expressed mostly in the upper portions of the epidermis, while desmoglein 3 (Dsg3) is expressed mostly in the basal and suprabasal layers of the epithelium. In the mucous membranes, Dsg3 is present in abundance throughout the epithelium, while Dsg1 is expressed to a much lower degree. Mucosal dominant pemphigus vulgaris (A) is characterized by autoantibodies against Dsg 3 and results in only mucosal lesions because Dsg1 compensates for the loss of Dsg3 in the skin. In the mucous membranes, Dsg1 cannot compensate resulting in intraepithelial blistering. In mucocutaneous pemphigus vulgaris (B), autoantibodies against both Dsg1 and Dsg3 are present. Thus, compensation occurs neither in the skin nor the mucous membranes, and blistering occurs in both locations. Pemphigus foliaceus (C) is characterized by autoantibodies against only Dsg1. This results in very superficial blisters in the skin. The mucous membranes are spared due to high levels of Dsg3 expression throughout the epithelium and low levels of Dsg1 expression.