The presence of anti-leukoblast antibodies as complement fixation agents in leukemia patients imm-nized with leukoblats treated with neuraminidase and radiation.

Six adult patients with acute myeloblastic leukemia were treated with chemotherapy and immunotherapy. This was done with cultured autologous leukoblasts, treated with neuraminidase of Vibrio cholerae and radiation, and injected six to ten times each eight to ten days between the chemotherapy cycles. Class IgC leukemic anti-leukoblast antibodies which are able to activate the C3 component of the complement system were found in the serum of patients. Five patients have been in complete remission for more than twenty months and the sixth patient for ten months. Antibodies for C3 fixation were not found in the serum of five other patients who were not immunized, nor in five healthy control subjects.