We describe a 30-year-old woman with systemic lupus erythematosus (SLE), in whom the only evidence of the disease, during the 10 years before diagnosis was established, was an accelerated erythrocyte sedimentation rate and a positive Wassermann test. Her disease was characterized by the presence of an anticoagulant without indication of bleeding, mixed cryoglobulinaemia, steroid-resistant renal damage, and persistent false-positive tests for syphilis. The relationship between these results and the presence of anticoagulant, mixed cryoglobulinaemia and renal damage in patients with SLE are discussed.