An attempt to obtain a specific antiserum forin vitro immunological conditioning of bone marrow in acute non-lymphoblastic leukemia

Summary An antiserum was produced in rabbits to acute undifferentiated leukemia (AUL) antigens. Partial absorption of the antiserum allowed the removal of the cytotoxic activity against normal mononuclear cells of peripheral blood and bone marrow, in contrast to blast cells from acute and chronic leukemias, which were killed by the antiserum in a standard NIH cytotoxicity test. These observations suggest that antigens present on blast cells of AUL are also expressed on some acute and chronic leukemic cells and that these antigens could be interpreted as B or leukemia-associated antigens because of the disappearance of all cytotoxic activity of the immune serum after extensive absorption with B cells from chronic lymphoid leukemia. Supported by grant no. 8001963.96 from theConsiglio Nazionale delle Ricerche (CNR), Roma, Italy andStiftung Volkswagenwerk, Bundesrepublik Deutschland.