Abstract
Mixed lymphocyte tumor cell reaction (MLTR) between peripheral lymphocytes and cryopreserved leukemia cells was performed in 36 adult patients with acute leukemia after they had been induced into complete remission by chemotherapy. In 20 patients their lymphocytes showed significant blastogeneic response to autochthonous leukemia cells. This MLTR was assumed to demonstrate the existence of tumor-associated antigens on the surface of the leukemia cells and gave a rationale for immunotherapy of acute leukemia. Thus, chemoimmunotherapy using cell-wall skeleton of BCG (BCG-CWS) was conducted in 28 patients with acute leukemia in complete remission. Chemotherapy consisted of monthly intensification therapy for 2 months and bimonthly thereafter. Immunotherapy with 200 μg of oil-attached BCG-CWS mixed with 107 autochthnous leukemic cells was given intradermally every week except when the patients were on maintence therapy. The therapeutic effectiveness was evaluated in 16 adult patients with acute non-lymphocytic leukemia, and was compared to that of a historical control group of 40 patients receiving chemotherapy alone. The BCG-CWS treated patients had a significantly but temporarily longer survival time than the control group although there was no difference in the first remission length.
