A case of long-standing classical rheumatoid arthritis complicated by serological and clinical characteristics of SLE.

A patient with RA who developed anti-Sm antibodies, a false positive serological test for syphilis (FPSTS), pericardial effusion, and leukopenia, 19-year after the onset of classical RA, is described. This case indicates a possible clinical association between the development of specific autoantibodies and clinical symptoms of SLE.