Safety and efficacy of fresh whole blood donor lymphocyte infusion in children.

Donor lymphocyte infusion (DLI) is a form of cellular immunotherapy which is known to be effective in preventing relapse in leukemia by inducing graft versus leukemia (GVL) effect. In hematopoietic stem cell transplantation (HSCT) for benign hematological conditions including primary immune deficiency, mixed chimerism is seen with the use of reduced intensity conditioning. DLI can help prevent graft rejection by boosting the existing graft in these situations. There is scant data on the use of DLI in children who have undergone HSCT for benign hematological disorders. We present our case series with early withdrawal of immunosuppression and DLI as a means to mitigate relapse of leukemia and prevent graft rejection in mixed chimerism in children transplanted for benign hematological disorders. Donor lymphocyte infusion was given in a graded regimen with the cell dose of 1 × 105 CD3 cells/kg (1 × 104/kg in haploidentical transplant), 5 × 105 CD3 cells/kg, 1 × 106 CD3 cells/kg depending on the graft kinetics and the clinical status of the children. A total of fifty eight children including those with haploidentical donors underwent DLI with an overall survival of 81.1%. The use of fresh whole blood in very small aliquots from the donor has made this technique cost effective and an attractive form of immunotherapy.