ISOLATION OF EPSTEIN-BARR-VIRUS-TRANSFORMED LYMPHOCYTES PRODUCING IGG CLASS MONOCLONAL-ANTIBODIES USING A MAGNETIC CELL SEPARATOR (MACS) - PREPARATION OF THYROID-STIMULATING IGG ANTIBODIES FROM PATIENTS WITH GRAVES-DISEASE

In autoimmune diseases, IgG class autoantibodies are generally considered to be more pathognomonic than IgM class ones. Although Epstein-Barr virus (EBV)transformation of lymphocytes is a useful method to obtain human monoclonal autoantibodies, it tends to result predominantly in IgM-producing cells. We depleted IgM(+) cells before EBV-transformation with a Magnetic Cell Separator (MACS) in order to increase the chance of acquisition of cells producing IgG class anti-thyrotropin (TSH) receptor antibodies (TRAb). As a result, we obtained four independent B cell clones producing IgG class monoclonal thyroid-stimulating antibodies (TSAb) from three patients with Graves' disease. None of these clones showed any TSH binding inhibitor immunoglobulin (TBII) activity, suggesting independence of TSAb-producing lymphocytes from those producing TBII. (C) 1995 Academic Press, Inc.