In situ localization of IgG in epidermolysis bullosa acquisita by immunogold technique

Epidermolysis bullosa acquisita (EBA) is an immunologically mediated mechanobullous dermatosis. Recently, serum antibodies in patients with EBA have been reported to bind to the carboxyl terminus of type VII collagen, the disease antigen. However, the precise localization of immunoglobulins in diseased skin has not been demonstrated.

In the present study skin samples taken from a 59-year-old man with EBA were processed for immunoelectron microscopy.

A preembedding immunogold ultrastructural technique was applied.

Gold particles, indicative of IgG binding, were deposited within the anchoring plaques and within the lamina densa in some perilesional skin sections. In a similar distribution, IgG-containing amorphous aggregates were detected within the basement membrane zone of perilesional and lesional skin. In some places these immunoglobulin deposits covered the whole region of anchoring fibrils.

These results demonstrate the precise localization of IgG within the basement membrane zone of EBA skin that corresponds to the carboxyl terminus of collagen VII in normal skin.