LDA-1 monoclonal antibody. An excellent reagent for immunofluorescence mapping studies in patients with epidermolysis bullosa.

To determine the diagnostic usefulness of a monoclonal antibody to the LDA-1 antigen, a newly defined noncollagenous component of the lamina densa of human basement membrane, we examined skin specimens from 20 patients with epidermolysis bullosa (simplex type, eight patients; junctional type, four patients; dystrophic type, eight patients) by the indirect immunofluorescence technique. We compared this antibody to polyclonal antibodies with three other antigens routinely examined in diagnostic immunofluorescence mapping studies. The antigen defined by the LDA-1 monoclonal antibody was expressed normally in all specimens examined, regardless of the type of epidermolysis bullosa present. Furthermore, no disparity was noted between the LDA-1 monoclonal antibody and a polyclonal antibody to type IV collagen in the microscopic localization of binding within induced skin blisters. These findings suggest that the LDA-1 monoclonal antibody is an excellent immunoreagent for diagnostic immunofluorescence mapping studies.