Immunopathology of cicatricial pemphigoid: studies of complement deposition.

Immunopathologic investigations were conducted on the sera and oral mucosal tissue specimens of 23 patients with cicatricial pemphigoid. A linear, continuous basement membrane zone pattern was noted in 83% of oral mucosal biopsy specimens studied. This pattern is indistinguishable from the pattern noted in immunofluorescence studies of bullous pemphigoid, herpes gestationis, and some cases of desquamative gingivitis. Complement studies provided data supportive of classical pathway activation in cicatricial pemphigoid tissue. Deposition of IgA with Factor B, properdin, and C3 raised the possibility of alternative pathway activation, a question requiring further study. Circulating antibasement membrane zone antibodies were noted in the sera of two patients with cicatricial pemphigoid.