ERADICATION OF MINIMAL RESIDUAL DISEASE DURING GRAFT-VERSUS-HOST REACTION INDUCED BY ABRUPT DISCONTINUATION OF IMMUNOSUPPRESSION FOLLOWING BONE-MARROW TRANSPLANTATION IN A PATIENT WITH PH-1-ALL

We observed a patient in whom graft-versus-host disease (GVHD) appeare d to induce a positive effect. This 32-year-old male with Philadelphia chromosome-positive acute lymphoblastic leukemia received a bone marr ow transplant (BMT) from an HLA-identical sibling donor. We analyzed t he bone marrow with the reverse transcriptase-polymerase chain reactio n to screen for the minor bcr/abl transcript, which indicates the pres ence of minimal residual disease (MRD). MRD was present in the pre-and post-transplant phases, There was no evidence of acute GVHD by post-t ransplant day 45. We abruptly discontinued the immunosuppressive thera py in an attempt to eliminate MRD by inducing an antileukemic reaction during GVHD, GVHD associated with diarrhea and liver dysfunction deve loped on day 64. On day 105, MRD disappeared and GVHD was treated with prednisolone and cyclosporin. The disappearance of MRD may have been due to the graft-versus-leukemia (GVL) effect mediated by the alloimmu ne response of donor T lymphocytes. These findings suggest that induct ion of the GVL effect may be useful for eliminating MRD after BMT in l eukemia patients at high risk of recurrence of the disease.