The immunological features and pathophysiology of ocular cicatricial pemphigoid.

Ocular cicatricial pemphigoid is an uncommon but severe and potentially blinding systemic disease. It shares many pathophysiological features with the other bullous skin diseases such as dermatitis herpetiformis, bullous pemphigoid and pemphigus vulgaris. All of these diseases have circulating antibodies that bind to the basement membrane of mucous membranes. The individual diseases differ by each having a specific component of the basement membrane complex as its antigen. In acute ocular cicatricial pemphigoid, the conjunctiva is infiltrated with neutrophils, macrophages, Langerhans cells and CD8+ and CD4+ T-cells while in the chronic disease the conjunctiva is infiltrated mainly by CD8+ T-cells. There is evidence of activation of these T-cells as CD4+ cells as shown by expression of the interleukin-2 receptor and increased expression of major histocompatibility class II antigens within the tissue. The aetiology of the fibrosis is unknown but increased amounts of several fibrogenic growth factors are demonstrable by immunohistochemistry.