Epstein-Barr Virus-Related Post-Transplantation Lymphoproliferative Disorders After Allogeneic Hematopoietic Stem Cell Transplantation

Epstein-Barr virus (EBV)-related post-transplantation lymphoproliferative disorders (EBV-PTLDs) are rare but potentially fatal complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT), characterized by uncontrolled proliferation of EBV-infected lymphocytes. The most common risk factors include T cell depletion of graft, HLA mismatch, severe graft-versus-host disease (GVHD), and EBV seromismatch (recipient-negative/donor-positive), among others. EBV-PTLDs commonly manifest as fever and lymphadenopathy and may rapidly progress to multiorgan failure and even death. Histopathological evidence is indispensable for the diagnosis, and positive findings of EBV-DNA (EBV-DNAemia) and imaging are also very helpful. Active prophylaxis, such as optimization of the donor choice, conditioning regimen, and GVHD prevention, or passive prophylaxis, such as low dose of rituximab, unselected donor lymphocyte infusion (DLI), and EBV-specific cytotoxic T lymphocyte (EBV-CTLs) infusion, can decrease the incidence of EBV-DNAemia. Rituximab- based preemptive treatment can prevent EBV-DNAemia from developing into EBV-PTLDs, particularly benefiting recipients with higher loads of EBV-DNA, although the long-term outcome has not been significantly improved. To date, there is no consensus as to whether and when to initiate prophylactic or preemptive treatment. The current treatment strategies for probable and proven EBV-PTLDs include reduction of immunosuppression (RI), rituximab, adoptive cell therapy (DLI or EBV-CTLs), chemotherapy, radiotherapy, and surgery, among which rituximab plus RI is the mainstay. However, the mortality of EBV-PTLDs remains considerably high, and novel strategies merit exploration.