Minimal residual disease-directed immunotherapy for high-risk myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation.

The efficacy of minimal residual disease (MRD)-directed immunotherapy, including interferon-α (IFN- α) treatment and chemotherapy plus granulocyte colony-stimulating factor-primed donor leukocyte infusion (chemo-DLI), was investigated in patients with high-risk myelodysplastic syndrome (MDS) who were MRD-positive after allogeneic hematopoietic stem cell transplantation (allo-HSCT). High-risk MDS patients who received non-T-cell-depleted allo-HSCT at the Peking University Institute of Hematology and were MRD-positive after allo-HSCT were studied (n = 47). The MRD-positive status was considered if leukemia-associated aberrant immune phenotypes or Wilms' tumor gene 1 expression is present in a single bone marrow sample. The cumulative incidence of the relapse and non-relapse mortality 2 years after immunotherapy were 14.5% and 21.4% (P = 0.377) and 9.1% and 0.0% (P = 0.985) for patients in the IFN-α and chemo-DLI groups, respectively. The probability of disease-free and overall survival 2 years after immunotherapy were 76.4% and 78.6% (P = 0.891) and 84.3% and 84.6% (P = 0.972) for patients in the IFN-α and chemo-DLI groups, respectively. Persistent MRD after immunotherapy was associated with poor survival. Thus, the MRD-directed immunotherapy was effective for patients with high-risk MDS who were MRD-positive after allo-HSCT, and the efficacy was comparable between chemo-DLI and IFN-α treatment.