Abstract: Objective To investigate the clinical progress of Epstein-Barr virus related post-transplant lymphoproliferative disorder (PTLD) after allogeneic hematopoietic stem cell transplantation (HSCT) in children with Wiskott-Aldrich syndrome (WAS). Methods Firstly, we retrospectively analyzed the clinical diagnosis and treatment data of one case of WAS after transplantation, and summarized relevant literature of WAS and PTLD. Then the risk factors, diagnosis and treatment progress of PTLD were discussed. Results A 12 -year-old boy with WAS underwent HLA 10 /10 allogeneic HSCT, and EBV activation at day + 33 after transplant was occurred, and then bilateral cervical lymph node enlargement appeared on day + 46 . The nucleic acid sorting results of T/B/NK virus in peripheral blood was as follows: EBV-B DNA 1 . 39 × 106 copies/mL, EBV-T DNA 1 . 35 × 105 copies/mL, EBV-NK DNA 1 . 71 × 102 copies/mL. PET-CT showed multiple lymph node enlargement in the right neck with increased FDG metabolism, which lead to consideration of lymphoma involvement. Neck lymph node biopsy results showed diffused large B-cell lymphoma, plasma blast cell phenotype, EBER (+), which confirmed the diagnosis of Epstein-Barr virus-associated PTLD. The child was given comprehensive treatments including antivirals, reduction of immunosuppression, rituximab, and low-dose chemotherapy. The enlarged lymph nodes disappeared, and the peripheral blood EBV DNA was negative at day + 69 . Conclusion For children with WAS from Epstein-Barr virus associated lymphocyte cloning PTLD after HSCT, when rituximab-refractoriness occurs, low-dose chemotherapy can help to achieve complete remission.

Key words: Wiskott-Aldrich syndrome; Epstein-Barr virus; risk factors; treatment