Abstract
A 76-year-old woman has got both lower limbs petechia and ecchymosis for 1 month, edema for 6 days and fever for 3 days. The patient suffered from purpura of both lower limbs, edema, arthralgia, recurrent fever, kidney damages, serositis, progressive reduction of platelet, moderate anemia and lymphadenopathy during the last two months. Laboratory examinations showed that her whole blood cells, platelet counts, serum albumin level and complements were all decreased and her titres of antibodies to double-stranded DNA (ds-DNA) were high. The patient had unequivocal SLE as she fulfilled seven American Rheumatism Association criteria (1997). Enzyme linked immunosorbent assays (ELISAs) for human immunodeficiency virus (HIV) was positive, while negative by Western blot analysis. A diagnosis of Systemic lupus erythematosus was made in view of the above findings. Because of the presence of autoantibodies and cross-reactivity, diagnosis of HIV infection should be cautious in patients with systemic autoimmune disease. The use of rigorous confirmatory testing by western blot analysis or immunofluorescence assay is therefore mandatory. More sensitive assays may be necessary to confirm the presence of HIV infection, such as gene amplification by the polymerase chain reaction, virus isolation and cultivation, the CD4 cell count and the ratio of CD4/CD8.