Development of anti-Sm and anti-DNA antibodies followed by clinical manifestation of systemic lupus erythematosus in an elderly woman with long-standing Sjögren's syndrome.

A 69-year-old Japanese women who had been followed up for 10 years as a primary Sjögren's syndrome, is reported. She suddenly developed serological and clinical characteristics of systemic lupus erythematosus (SLE): anti-Sm and anti-dsDNA antibodies followed by nephrotic syndrome and pancytopenia. This case suggests that the diagnosis of primary Sjögren's syndrome should be considered as tentative in certain cases and that the development of serological characteristics precede and are associated with the development of clinical symptoms of SLE.