Donor leukocyte infusions inducing remissions repeatedly in a patient withrecurrent multiple myeloma after allogeneic bone marrow transplantation

We describe a patient with recurrent relapses after allogeneic BMT for mult iple myeloma who repeatedly went into CR after donor leukocyte infusions (D LI). The first bone marrow relapse, 24 months after allogeneic BMT, was tre ated successfully with the infusion of 1.2 x 10(8) donor T cells. The secon d extramedullary relapse, 18 months later with a pleural mass and midthorac ic spine process, responded again to DLI, however, only after three courses were given, each with escalating doses of T cells, The pleural mass was tr eated successfully with radiation therapy after the second DLI but reappear ed 3 months later and responded again to the final DLI course with 5 x 10(8 ) T cells/kg. Nevertheless, graft-versus-host disease (GVHD) did not occur. Retrospective analysis of minimal residual disease in bone marrow aspirate s during CR periods using a sensitive quantitative tumor-specific PCR showe d that BM tumor cell infiltration persisted. The possible clinical implicat ions of this case report, like maintenance DLI and the aim for molecular re missions, are discussed.