The use of cellular immunoadsorbents to prepare antibody that distinguishes between syngeneic surface antigens on two guinea pig hepatocarcinomas: Xenogeneic antibodies with reactivity for surface determinants of guinea pig line-10 hepatocarcinoma cells were isolated using cellular immunoadsorbents prepared by coupling formalin treated line-10 cells to DE-52. Antibodies prepared in this manner exhibited a high degree of reactivity for line-10 surface determinants. They also reacted to some extent with surface determination of syngeneic line-1 cells. Further restriction of antibody reactivity was accomplished by passing the antibodies through cellular immunoadsorbents prepared with line-1 cells. By direct binding studies, these antibodies showed significantly reduced activity for line-1 cells and no reactivity for guinea pig spleen cells or for unrelated murine EL-4 lymphoma cells. By a competitive radioimmunoassay these antibodies reacted only with determinants expressed on the surfaces of line-10 cells and not on line-1, L2C, spleen, thymus or EL-4 cell surfaces. The sequential use of immunoadsorbents made of antigenically distinct syngeneic tumor cells made it possible to prepare antibodies with restricted reactivity for line-10 associated antigens and is an additional approach by which "tumor-specific" antibodies can be prepared. Immune complexes (IC) in children with leukemia: Relationship to disease characteristics and antibody response to BCG in patients receiving BCG immunotherapy. Determinations were made in sera obtained at three-month intervals from individual children with leukemias over a two-year period. At time of diagnosis, IC were found in sera from 6 of 41 patients with acute lymphoblastic leukemia (ALL). Three of 6 patients with T cell leukemia had IC at diagnosis, as compared to 3 of 55 with null cell leukemia. Of the patients followed for 6 months or more, 34% had IC during therapy and the incidence of relapse was unrelated to the presence or absence of IC. The presence of IC by themselves did not portend either a favorable or an unfavorable prognosis. Sera taken at the time of diagnosis from children with acute non-lymphoblastic leukemia had a higher incidence, 36% with IC, than sera from ALL patients (15%). Antibodies in sera from ALL patients at diagnosis had a lower capacity to bind a BCG antigen than sera from normal controls. (Text Abridged.)