In situ detection of inflammatory cytokines and apoptosis in pemphigus foliaceus patients.

Context: Endemic pemphigus foliaceus, or fogo selvagem, is a chronic autoimmune disease characterized by the formation of intraepidermal blisters that reduce adhesion between keratinocytes. Endemic pemphigus foliaceus is associated with the presence of autoantibodies and high levels of cytokines involved in the inflammatory response.

Objectives: To evaluate the expression of the proinflammatory cytokines interleukin 1, interferon gamma, and tumor necrosis factor alpha; the proapoptotic inducers Fas and inducible nitric oxide synthase; and the apoptosis inhibitor Bcl-2; and to evaluate the presence of apoptosis.

Design: Skin biopsies from 13 patients with endemic pemphigus foliaceus and controls were evaluated by immunohistochemistry and apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay.

Results: Proinflammatory cytokines were only detected in cells of the inflammatory exudate. Inducible nitric oxide synthase, Fas, and Bcl-2 were expressed by both epithelial and inflammatory cells. Epithelial apoptosis was observed in 12 cases (92.3%), and subepithelial apoptosis in 11 cases (85%).

Conclusions: This study suggests that apoptosis as well as the local production of proinflammatory cytokines are associated with endemic pemphigus foliaceus lesions. These results may contribute to the development of new therapeutic approaches to endemic pemphigus foliaceus.