AUTOANTIBODY AGAINST NA+ I- SYMPORTER IN THE SERA OF PATIENTS WITH AUTOIMMUNE THYROID-DISEASE/

Using recombinant rat Na+/I- symporter (NaIS) protein, we have immunoc hemically searched for the autoantibody in the sera from patients with autoimmune thyroid disease. We found that 22 out of 26 sera (84%) fro m patients with Graves' disease and 3 out of 20 sera (15%) from patien ts with Hashimoto's thyroiditis recognized it. By Western blot, these IgGs reacted with 80 kDa protein in FRTL-5 cell membrane, which co-mig rated with the band stained by rabbit antibody toward NaIS. These resu lts indicate that autoantibody against NaIS, newly identified antibody , frequently exists in patients with autoimmune thyroid disease, espec ially in Graves' disease. (C) 1996 Academic Press, Inc.