Comparison of ATLG and ATG for Immune Reconstitution After Allo-HSCT for Hematologic Malignancy

Allogeneic hematopoietic stem cell transplantation is the only curative treatment for malignant hematologic diseases. However, immune rejection is a major limitation in its application. In the "Beijing Protocol", the use of granulocyte colony-stimulating factor (G-CSF) in combination with anti-thymocyte globulin (ATG) can achieve "everyone has a donor". The use of ATG, however, can interfere with the recovery of immune function after transplantation, increasing the risk of life-threatening complications such as viral infections or graft-versus-host disease. Rabbit anti-human T-lymphocyte immunoglobulin (ATLG) is currently approved for the prevention of organ transplant rejection, which is produced differently from ATG. Previous studies have shown that transplant preconditioning with ATLG is effective in preventing graft-versus-host disease and even reduces the incidence of cytomegalovirus, etc. after transplantation. In this study, we will prospectively apply containing ATLG in a cohort of allogeneic hematopoietic stem cell transplantation for malignant hematologic diseases and dynamically observe the state of immune reconstitution of patients after transplantation. We will also compare it with a matched cohort of conventional combined ATGs during the same period to explore the impact of ATLG on immune reconstitution after transplantation.