BACKGROUND: Antithymocyte globulin or human Jurkat T-cell-line-derived antilymphocyte globulin is used in allogeneic stem cell transplantation to induce in vivo T-cell depletion to facilitate engraftment and lower graft-versus-host disease. In vitro studies suggest that antithymocyte globulin, besides causing T-cell depletion, has strong anti-myeloma activity. DESIGN AND METHODS: We evaluated the anti-myeloma activity of antilymphocyte globulin in a melphalan/fludarabine-based reduced intensity conditioning regimen as well as the incidence of graft-versus-host disease in 138 multiple myeloma patients who underwent allogeneic stem cell transplantation with (n=79) or without (n=59) antilymphocyte globulin. RESULTS: Leukocyte and platelet engraftment were faster in the group not receiving antilymphocyte globulin (13 vs. 16 days, p
