Two patients with erosive lichen planus and latent HBV infection who had circulating antibodies directed to nuclei of epithelial cells are described. The nature of such antigen has been investigated by indirect immunofluorescence, double immunodiffusion, counterimmunoelectrophoresis, enzyme-linked immunosorbent assay, enzyme treatments, and immunoblotting. The antigen cannot be identified as RNP, histone, soluble nuclear protein, nDNA, or ssDNA. It may be a DNA protein complex and preliminary immunoblotting data support the thesis that it may be a multimolecular complex.