Molecular Remission Through Donor Lymphocyte Infusion in Post-Transplant Secondary Myelofibrosis: Managing Early Relapse Signs

Symptomatic myelofibrosis (MF) often requires allogeneic hematopoietic stem cell transplantation (allo-HSCT) for a potential cure, but relapse and graft-versus-host disease (GVHD) remain critical post-transplant challenges. Here, we present the case of a 45-year-old woman with polycythemia vera who developed secondary MF and underwent haploidentical allo-HSCT. A preemptive donor lymphocyte infusion (DLI) at month 29, following signs of relapse, restored donor chimerism and reduced the JAK2 mutation, achieving molecular remission. Mild chronic GVHD was effectively managed. This case highlights the utility of MRD and chimerism monitoring and the efficacy of preemptive DLI in secondary MF.