A paraneoplastic mixed bullous skin disease: breakdown in tolerance to multiple epidermal antigens

We report a new type of paraneoplastic mixed bullous skin disease in a pati ent with a B-cell lymphoma associated with monoclonal IgM kappa paraprotein aemia. The patient's clinical and histological features were reminiscent of bullous pemphigoid. Characterization of antiepidermal antibodies by immuno blotting and indirect immunoelectron microscopy demonstrated a novel patter n of reactivity: IgG antibodies were directed against desmoplakins I-II and BPAG2, and were associated with antidesmoglein 3 polyclonal IgM antibodies . Such an autoreactive pattern involving antidesmoplakins, anti-BPAG2 and a ntidesmoglein 3 antibodies has not been previously reported. It reflects th e breakdown of tolerance to multiple epidermal antigens observed in some pa tients with malignancy.