A mouse monoclonal antibody against a newly discovered basement membrane component, the epidermolysis bullosa acquisita antigen.

A mouse monoclonal antibody, H3a, directed against the newly described epidermolysis bullosa acquisita (EBA) antigen was obtained using hybridoma techniques. The distribution of the monoclonal antibody is identical to that of the polyclonal serum antibody of patients with EBA. By immunofluorescence, a linear band is seen at the dermal-epidermal junction and, by immunoelectron microscopy, immune reaction products are present in the lamina densa and sublamina densa regions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by Western immunoblot analysis shows that the monoclonal antibody recognizes 290 and 145 kilodalton proteins present in the immunizing junctional extract, identical with the newly discovered EBA antigen. This monoclonal antibody should be useful in the further isolation and characterization of the EBA antigen.