Anti-thymocyte globulin to prevent complications after transplant in patients with acute lymphoblastic leukemia

This study aimed to investigate the effect of anti-thymocyte globulin on the outcomes of allogeneic peripheral blood stem cell transplantation in patients with Philadelphia negative acute lymphoblastic leukemia.

This study concluded that this group of patients benefited from the use of anti-thymocyte globulin.

Stem cell transplants are a common treatment option for acute lymphoblastic leukemia (ALL). Mobilized peripheral blood stem cells can be used in transplants to replace blood forming stem cells. They are most commonly used for allogeneic peripheral blood stem cell transplantation (allo-PBSCT). Bone marrow contains stem cells and can also be used in transplants.

The use of peripheral blood stem cells is associated with an increased risk of chronic graft-versus-host disease (cGVHD) when compared to bone marrow. cGVHD occurs when the stem cells view the body as foreign and attack it. Anti-thymocyte globulin (ATG) is a treatment that may prevent transplant rejection. It was not known if the addition of ATG would reduce the incidence of cGVHD.

This study involved 924 Philadelphia negative ALL patients (ALL not caused by abnormal chromosomes) who underwent allo-PBSCT during their first remission. ATG was administered to 404 patients before they underwent allo-PBSCT (ATG group). Relapse-free survival, severe acute GVHD and chronic GVHD were measured.

The ATG group had an improved chance of GVHD-free survival and relapse-free survival when compared to the other group. The ATG group were 34% less likely to have grade 2-4 acute GVHD and 42% less likely to have grade 3-4 acute GVHD when compared to the other group. The ATG group were 55% less likely to experience total chronic GVHD and 70% less likely to experience extensive GVHD when compared to the other group. The ATG group were 42% less likely to experience nonrelapse mortality (death without disease return) when compared to the other group.

The addition of ATG had no significant effect on leukemia-free survival or overall survival. The ATG group were 40% more likely to experience a relapse when compared to the other group.

This study concluded that patients with Ph-negative ALL who underwent allo-PBSCT benefitted from the use of ATG.

Consult your physician about the use of ATG before a transplant.