97-kDa Linear IgA Bullous Dermatosis (LAD) Antigen Localizes to the Lamina Lucida of the Epidermal Basement Membrane

摘要: Linear IgA bullous dermatosis (LAD) is an autoimmune blistering disease in which autoantibodies develop against the epidermal basement membrane zone. Target antigens of circulating are thought to be heterogeneous, and their ultra-structural localization has not been fully elucidated. Previous studies with immunoblotting have demonstrated that 97-kDa autoantigen detected most frequently patients' sera a major LAD antigen. Although recent report suggests antigen localized hemidesmosomal plaques adjacent lamina lucida, discrepancies still exist among previous immunoelectron microscopic findings. To identify precise antigen, we used two different low-temperature techniques. For iinmunolabeling, selected five had high titer A post-embedding method cryofixation freeze substitution failed immunolabel Cryoultramicrotomy microscopy succeeded preserving antigenicity In all cases, majority labeling occurred lucida beneath hemidesmosomes. No specific was observed attachment or densa sublamina region, including anchoring fibrils. These results indicate component lucida.