Novel facts about an old marker: the LE cell

For more than fifty years, lupus erythematosus (LE) cells were believed to result from in ito opsonization of bare nuclei by serum antinuclear antibod ies and their ultimate phagocytosis by neutrophils. Twenty years ago, we de scribed that certain antinuclear antibodies could enter into viable cells, and later on, it was proved that penetration of anti-DNA antibodies into ce lls results in protracted active cell death. Recent findings indicate that the material engulfed by LE cells are apoptotic blebs as residuals of cells dying after penetration of anti-DNA antibodies. These observations not onl y change the interpretation of the presence of the LE cell phenomenon, but also stress the potential pathophysiological role of antibodies to intracel lular antigens in autoimmune diseases.