Epidermolysis bullosa: variability of expression of cicatricial pemphigoid, bullous pemphigoid, and epidermolysis bullosa acquisita antigens in clinically uninvolved skin.

Indirect immunofluorescence was performed on skin from 13 patients with epidermolysis bullosa (EB) (simplex, 6; junctional, 2; dystrophic, 5) to compare the expression of 3 basement membrane components, bullous pemphigoid (BP) antigen, cicatricial pemphigoid (CP) antigen, and epidermolysis bullosa acquisita (EBA) antigen, in clinically uninvolved tissue. In addition, expression of laminin, type IV collagen, and KF-1 antigen was also evaluated. Whereas laminin, type IV collagen, and KF-1 antigen were each detectable in EB skin in a manner identical to that previously reported, marked variability was noted in the expression of BP, CP, and EBA antigens. However, no correlation was noted comparing lack of expression of any one of these latter antigens with either of the remaining two. Of these 3 antigens, BP antigen was the least often detectable, particularly in skin from patients with EB simplex. The lack of detectable BP antigen in EB simplex skin appeared to correlate with more extensive disease involvement and/or younger patient age. These findings may, therefore, limit the usefulness of BP serum in immunofluorescence mapping. Additionally, the disparity in expression of basement membrane antigens defined by BP and CP sera suggests that BP antigen and CP antigen are distinct entities.