Preincubation of donor bone marrow cells with a combination of murine monoclonal anti-T-cell antibodies without complement does not prevent graft-versus-host disease after allogeneic marrow transplantation.

Protection of mice against graft-versus-host disease (GVHD) can be accomplished by incubating donor marrow with anti-T-cell antisera or with anti-Thy-1 monoclonal antibody. Incubation of donor marrow with a single anti-T-cell monoclonal antibody, however, does not prevent GVHD in humans. Therefore, we carried out a clinical trial to determine the effect of treatment of donor marrow with a combination of eight anti-T-cell antibodies in the absence of complement. The nine patients were genotypically HLA identical with their donors and received methotrexate postgrafting. Prompt engraftment occurred in eight patients. Of six patients surviving at least 40 days with sustained engraftment, three had severe (grade III or IV) GVHD. Thus, there is no evidence that treatment of donor marrow with murine anti-T-cell monoclonal antibodies as described here can prevent GVHD.