The presence of autoantibodies is not necessarily pathologic and has to be related to the age group, gender, and clinical condition of the patient.

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 are autoimmune intraepidermal blistering diseases in which immunoglobulin G (IgG) autoantibodies are directed against desmosomal glycoproteins. The aim of this study was to determine the IgG subclass profile of endemic pemphigus foliaceus (fogo selvagem) and pemphigus vulgaris utilizing indirect immunofluorescence. PATIENTS AND METHODS:Twenty-five patients with pemphigus vulgaris, 25 with endemic pemphigus foliaceus (fogo selvagem), and 25 healthy controls were analyzed by indirect immunofluorescence for circulating autoantibodies (total IgG and its subclasses).RESULTS: Our data revealed a significant correlation (P <.05) of disease activity and autoantibody levels in both forms of pemphigus, i.e., negative titers related to clinical remission, whereas positive results related to active disease. Immunoglobulin G subclass analysis in fogo selvagem demonstrated that in patients in remission, 56% showed positive immunoglobulin G4; in active disease, immunoglobulin G4 was the predominant subclass (100% positive in all cases). The IgG subclass profile in pemphigus vulgaris showed that in patients in remission, only 10% were positive for immunoglobulin G4; in active disease, positivity for immunoglobulin G4 was present in 78% to 88% of the cases.CONCLUSION: Subclass characterization of immunoglobulin G autoantibodies is a useful tool for pemphigus followup, since immunoglobulin G4 (IgG4) is the subclass that is closely related to recognition of pathogenic epitopes, and consequently with disease activity. Careful monitoring should be performed for fogo selvagem in clinical remission with a homogeneous IgG4 response, since this may indicate more frequent relapses.

Abstract:Immunological mapping, an immunofluorescence technique, is currently the method most used to diagnose and differentiate the principal types of hereditary epidermolysis bullosa, since this technique is capable of determining the level of cleavage of this mechanobullous disease Keywords: Collagen; Epidermolysis bullosa; Laminin; Fluorescence Microscopy Resumo: O imunomapeamento, uma técnica de imunofluorescência, é o método atual mais utilizado para o diagnóstico laboratorial e a diferenciação dos principais tipos de epidermólise bolhosa hereditária, uma vez que determina o plano de clivagem na junção dermo-epidérmica das doenças mecanobolhosas.