Donor lymphocyte infusion induced molecular remission in relapse of acute myeloid leukaemia after allogeneic bone marrow transplantation

Donor lymphocyte infusion (DLI) has been used successfully to induce remiss ions in relapse of acute myeloid leukaemia (AML) after bone marrow transpla ntation (BMT), but molecular eradication of leukaemia has rarely been docum ented. A patient with AML-M4Eo relapsed after HLA-identical sibling BMT in first complete remission (CR), Cytogenetic and molecular genetic investigat ions confirmed inv(16) and CBF beta/MYH11 fusion characteristic of M4Eo, A second remission was obtained with chemotherapy. Full donor chimerism was d emonstrated by fluorescence in situ hybridisation, However, molecular evide nce of minimal residual disease still persisted, and donor lymphocyte infus ion (DLI) was administered. This resulted in molecular eradication, and the patient remained in clinical and molecular remission 16 months from DLI, O ur observations showed that, for AML relapse after BMT, molecular leukaemia eradication could be achieved by DLI so that, in cases where genetic marke rs are available, molecular monitoring should be performed to assess the ef ficacy of treatment.