Abstract:Immunofluorescence is a valuable auxiliary diagnostic tool for autoimmune bullous diseases and inflammatory disorders, since their clinical and histopathologic findings may be inconclusive. It is a feasible laboratory method that requires experienced technicians and detects in situ and circulating immune deposits that may be involved in the pathogenesis of such skin diseases. Keywords: Autoimmunity; Basement membrane; Fluorescent antibody technique; Pemphigus Resumo: A imunofluorescência é um valioso instrumento auxiliar no diagnóstico das dermatoses bolhosas autoimunes e desordens inflamatórias, uma vez que seus achados clínicos e histopatológicos podem não ser determinantes. Consiste em um método laboratorial factível, que requer profissionais técnicos experientes, e detecta imunocomplexos in situ e/ou circulantes, que podem estar envolvidos na patogênese de tais enfermidades cutâneas.

Pemphigus refers to a group of human autoimmune blistering diseases involving skin and/or mucous membranes. Endemic pemphigus foliaceus (EPF), or fogo selvagem is an organ-specific autoimmune blistering disease, first reported in the beginning of the 20th century in rural areas of Brazil. The disease follows the course of streams and creeks, and vanishes after urbanization of the endemic areas. The auto-antigen related to EPF is desmoglein 1, a 160 kDa glycoprotein of the desmossomal core, targeted by in situ and circulating IgG autoantibodies, mainly of the IgG4 subclass.

The present data suggest that in vivo ANA evaluation is an additional and feasible auxiliary tool for diagnosing CTDs.

All 10 patients with pemphigus with umbilical presentation had the clinical and immunopathological features of either PF or PV. This peculiar presentation, not yet completely elucidated, has rarely been reported in the literature. A possible explanation for this unique presentation may be the presence of either novel epitopes or an association with embryonic or scar tissue located in the umbilical-cord region.