Specific immunotherapy of acute lymphoid leukemia patients by REH cell line

Of 25 patients with acute lymphoid leukemia (ALL) in remission who were submitted to immunotherapy with BCG plus irradiated REH cells, 17 had positive sera in microcytotoxicity against REH cells after immunization. The follow-up of 28 months indicates that the microcytotoxicity varies in the same patient and may become negative and positive again. The results obtained after convenient absorption of one positive serum strongly suggest that REH cells in leukemic patients can raise antibodies directed against an antigenic structure closely related to the cALL antigen. Moreover, REH cells demonstrate in vitro suppressive activity, which could be a common property of some subcategories of human ALL.