Remission With Donor Lymphocyte Infusion in a Child With Marrow Relapse After Haploidentical Stem Cell Transplantation for Relapsed Stage 4 Neuroblastoma.

A 7-year-old male with Stage 4 neuroblastoma was treated with chemotherapy and autologous hematopoietic stem cell transplantation (HSCT), resulting in partial response with residual bone and marrow disease. He proceeded to haploidentical-HSCT with his mother as donor and achieved remission. The patient developed marrow relapse 2 years after haploidentical-HSCT with cytopenia and dropping donor chimerism. Donor lymphocyte infusion (DLI) using mother's whole blood was given resulting in clearance of marrow disease, resolution of cytopenia, and full donor chimerism. This is the first report of successful treatment for neuroblastoma relapse after haploidentical-HSCT using DLI alone, supporting the role of adoptive cell therapy post-HSCT in neuroblastoma.