Antibodies to cytoplasmic antigens in lupus erythematosus. Serologic marker for systemic disease.

Seven patients with classic cutaneous lupus erythematosus are described. Three of these patients had features satisfying four of the American Rheumatism Association (ARA) preliminary criteria for the diagnosis of systemic lupus erythematosus (SLE). Their sera, however, lacked antinuclear antibodies but demonstrated precipitating antibodies reactive against cytoplasmic RNP (La) and non-nucleic acid (Ro) antigens. Four additional ANA-negative patients lacking significant skin disease but having a lupus-like multisystem disease were found to have antibodies to soluble cytoplasmic antigens. Thirty-three of 130 ANA-positive SLE patients, but none of 16 discoid lupus patients, possessed these anticytoplasmic antibodies. These findings suggest that antibodies to Ro and La may be a marker for systemic disease in ANA-negative patients with 1) cutaneous lupus and 2) a distinct subpopulation of patients with a lupus-like syndrome without skin disease.