A recent paper published in Bone Marrow Transplantation describes a retrospective study conducted at the University Medical Center Hamburg-Eppendorf (UKE) on a total of 289 patients with various hematological diseases who received matched unrelated (MUD) allogeneic hematopoietic cell transplants with peripheral blood stem cells (PBSC-allo-HCT).  

The use of an unrelated donor and PBSC-allo-HCT is associated with an increased risk of graft-versus-host disease (GvHD). Pre-transplant therapy with anti-T-lymphocyte globulin (ATLG) in the allo-SCT setting has been shown to prevent severe acute and chronic GVHD, however optimal ATLG dosing regimens are not well defined. 

The primary goal of the study was to compare immune reconstitution (IR) kinetics and transplant outcomes in two groups of patients receiving ATLG treatment at 30 mg/kg (ATLG 30, n=73) and 60 mg/kg (ATLG-60, n=216). A significant delay in leukocyte and platelet engraftment was observed in the ATLG-60 compared with the ATLG-30 group. No significant differences in incidence of CMV reactivation before day 100 were evident. Cumulative incidence of infections overall and EBV reactivation until day 100 were significantly lower in the ATLG-30 compared with the ATLG-60 group. In the ATLG-30 group, there was faster reconstitution of naïve-B cells and γδ T cells at day +30 and a faster naïve helper T-cell, NK-cells, and naïve B-cell reconstitution at day +180.

There were no significant differences in cumulative incidence of aGvHD, cGvHD, NRM, relapse, PFS, or OS between the groups. The authors conclude that the choice of ATLG dose has significant impact on IR post MUD-allo-SCT: higher doses reduce aGVHD but delay engraftment, impair immune cell reconstitution, and increase the risk of infection.

Reference:

Massoud R, Klyuchnikov E, Gagelmann N, Zabelina T, et al. Impact of Anti-T-lymphocyte globulin dosing on GVHD and Immune reconstitution in matched unrelated myeloablative peripheral blood stem cell transplantation. Bone Marrow Transplantation (2022). https://www.nature.com/articles/s41409-022-01666-x

Tags: AlloHCT, patient care, GVHD, Outcomes, Relapse, NRM, Cellular therapy, hematologic, Bone Marrow Transplantation, peripheral blood, engraftment, leukocyte, hematopoietic cell transplantation, immune response