Intrathecal application of donor lymphocytes in leukemic meningeosis after allogeneic stem cell transplantation.

Extramedullary relapses after allogeneic stem cell transplantation, especially within the central nervous system (CNS), are not only difficult to treat but also associated with poor outcome. Although the graft-versus-leukemia (GvL) effect is nowadays accepted and well documented, it remains controversial whether one can make use of GvL effects in immunological-restricted areas ("sanctuary sites") like the central nervous system. Here, we present data of three hematological patients suffering from isolated CNS relapse of CML or AML after allogeneic stem cell transplantation. Patients received in addition to chemotherapy intrathecal infusions of donor lymphocytes by CD14 depletion of peripheral blood mononuclear cells from the correspondent allogeneic donor. Referring to an observation period of maximum 17 months no immediate or delayed side effects could be detected.