Epidermolysis bullosa acquisita (EBA) is an autoimmune blistering disease of the skin ocota-
curring mostly in middle-aged persons with characteristic skin lesions of inflammatory in a vesiculobullae and mechanobullous lesions. Separation of the skin occurs at the dermoepi-
dermal junction (DEJ) initiated by an immune process involving the anchoring fibrils (AF) 764, which have a role in the normal adherence of the epidermis and the dermis. Patients with !sta -
EBA have autoantibodies of IgG to type VII collagen which is the main component of AF´
An electron microscopic. picture of normal DEJ is shown in figure 1, and the antigen site 2011s of this disease (AF) is noted at the upper-most part of the dermis.
son In EBA, a biopsy specimen shows subepidermal bulla with a variable degree of dermal in-filtrates. Immunofluorescence (IF) demonstrates a linear deposit of IgG. The pattern of imani-
mune deposits along the DEJ is similar to that of bullous pemphigoid. However, the linear iing. fashion is thicker and coarser´. When examined by the indirect method with a semi-horizontal section of normal human skin substrates the same patterns can be observed: a fine
situ linear deposit with bullous pemphigoid antibodies and a slightly coarser linear pattern with
)pl): EBA antibodies. With salt-split skin substrates, the serum autoantibodies of IgG are found
I to be bound only to the dermal side, the AF zone (Fig. 2). This immunopathologic study can provide a diagnostic finding´. Transmission electron microscopic examination reveals in-
land the blister to be localized just beneath the lamina densa, the site of the immune deposit.
In immunoblot analysis of the patient´s serum against the. dermal extracts, serum antibod-
-logy ies are found to recognize type VII collagen of 290/145 kD (Fig. 3). This is a confirmatory
scot, technique (with antibody-positive sera) in the diagnosis of EBA".
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