Improved Myeloablative Allogeneic Hematopoietic Stem Cell Transplantation Protocol for the Treatment of Epstein Barr Virus T/NK Lymphoproliferative Disease (EBV-T/NK LPD) and Prevention of Post Transplant Graft-versus-host Disease

Improved Myeloablative Allogeneic Hematopoietic Stem Cell Transplantation Protocol for the Treatment of Epstein Barr Virus T/NK Lymphoproliferative Disease (EBV-T/NK LPD) and Prevention of Post Transplant Graft-versus-host Disease

To investigate whether the addition of recombinant humanized anti-CD25 monoclonal antibody to the conventional EBV-T/NK LPD conditioning regimen can prevent acute and chronic GVHD after transplantation, improve the severity of GVHD and have a corresponding impact on other related post-transplant complications such as poor engraftment, thrombotic microvascular disease, early EBV reactivation and relapse.

Inclusion Criteria:

• Meet the diagnosis of EBV-T/NK lymphoproliferative disease (EBV-T/NK LPD) according to the ICC2022 diagnostic criteria
• Plan to undergo allogeneic hematopoietic stem cell transplantation (allo HSCT) in our hospital
• Age ≤ 18 years old
• Sign informed consent form
• Meet one of the following conditions (haploid donors must meet one of the above conditions, unrelated donors must meet two of the above conditions): ① donor age≥40 years old; ② The donor source is unrelated donor or haplotype related female or collateral donor (brother sisters, etc.) with ≥ 1 point mismatch; ③ CD3≥4 x 10 ^ 8/kg before transplantation; ④ The primary disease is in an HLH (hemophagocytic lymphohistiocytosis) flare or active disease phase; ⑤ ATG (or ATLG (1:2)/ALG (1:20) equivalent dose)<10mg/kg

Exclusion Criteria:

• The expected survival period for multiple organ failure is no more than 3 months
• Not signing the informed consent form