Epstein-Barr Virus–Related Post-Transplantation Lymphoproliferative Disorder after Unmanipulated Human Leukocyte Antigen Haploidentical Hematopoietic Stem Cell Transplantation: Incidence, Risk Factors, Treatment, and Clinical Outcomes

• We examined post-transplantation lymphoproliferative disease after unmanipulated haploidentical hematopoietic stem cell transplantation.
• Two-year probability of overall survival was 42.8% for patients with post-transplantation lymphoproliferative disease patients, poorer than that of controls.
• Poorer immune reconstitution increased the risk of post-transplantation lymphoproliferative disease after haploidentical hematopoietic stem cell transplantation.
• Rituximab-based therapy helped to improve the outcomes.

We examined the incidence, risk factors, treatments, and clinical outcomes of post-transplantation lymphoproliferative disorder (PTLD) after unmanipulated haploidentical (haplo) hematopoietic stem cell transplantation (HSCT) in 1184 patients between 2006 and 2012. Age-, transplantation time–, and transplantation duration–matched controls were randomly selected from the same cohort. Forty-five patients experienced PTLD. The median time from HSCT to PTLD occurrence was 61 (range, 33 to 360) days and the 1-year cumulative incidence of total PTLD after haplo-HSCT was 3.0%. In multivariate analysis, a lower absolute count of CD8+ T lymphocytes at day 30, a lower absolute count of immunoglobulin M at day 30, and cytomegalovirus DNAemia after HSCT were significantly associated with higher risk of PTLD. The 2-year probability of overall survival (OS) after HSCT was 42.8%, which was comparable between the probable PTLD and the proven PTLD patients. Patients who received rituximab-based therapy had significantly better 2-year OS (48.2% versus 13.2%, P = .02). Thus, we were able to identify individuals at a high risk of developing PTLD after unmanipulated haplo-HSCT. Rituximab-based therapy can help to improve the outcomes of PTLD patients.