OBJECTIVE To summarize the clinical characteristics, risk factors of Epstein-Barr virus (EBV) infection in children undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), and the impact of EBV infection on prognosis under the context of preemptive treatment with rituximab.

METHODS A retrospective analysis was conducted on the clinical data of patients who underwent allo-HSCT at Shenzhen Children′s Hospital from Jan. 2019 to Dec. 2023. The occurrence of EBV viremia and EBV-associated post-transplant lymphoproliferative disease (EBV-PTLD) was observed, and their risk factors and prognosis were analyzed.

RESULTS Among the 1 027 patients, 244 (23.76%) developed EBV viremia, with a median onset time of 86.00 (61.00~221.00) days after transplantation, while 44 patients (4.28%) developed EBV-PTLD, with a median onset time of 77.00 (55.50~140.50) days after transplantation. Multivariate logistic regression analysis revealed that the use of rituximab within six months prior to transplantation was a protective factor against EBV viremia after allo-HSCT, while risk factors included primary diseases being bone marrow failure disorders, donor EBV core antigen antibody and the use of anti-thymocyte globulin (ATG). The cumulative incidence rates of EBV viremia in 1 year were 10.00%, 26.88% and 50.00% for patients who did not receive ATG, received ATG at a dose of 0-10 mg/kg, and received ATG at a dose ≥10 mg/kg, respectively (P < 0.001). High-risk factors for EBV-PTLD included female recipients, the occurrence of EBV viremia after transplantation and ATG dosage ≥10 mg/kg, while the use of rituximab within six months prior to transplantation was not a protective factor against EBV-PTLD (P=0.117). The overall survival rates of patients with EBV viremia and EBV-PTLD were (97.50±0.010)% and (97.70±0.022)%, respectively, with no significant difference compared to those without these conditions (P=0.634, P=0.899).

CONCLUSIONS EBV infection is a common complication in children after allo-HSCT. The use of rituximab within six months prior to transplantation can reduce the occurrence of EBV viremia. An ATG dosage ≥10 mg/kg is a common high-risk factor for both EBV viremia and EBV-PTLD. Under the context of preemptive treatment with rituximab, EB nirus viremia and EBV-PTLD may not significantly affect patient survival and prognosis.