Anti-Sa antibody

Anti-Sa antibody is an autoantibody that appears in the serum of patients with rheumatoid arthritis and is reported in 1994 by Despres. The target antigen (Sa antigen) was first found in the human spleen, and later found in the human placenta and rheumatoid synovium, which may be a normal tissue component of the human body. Using immunoblot analysis, the molecular weight of Sa antigen in human spleen was 50 kD, while that of human placental Sa antigen was 50 and 55 kD.