Differential Effect of Graft-versus-Host Disease on Survival in Acute Leukemia according to Donor Type

The anti-leukemic activity of allogeneic hematopoietic cell transplantation (HCT) depends on both the intensity of conditioning regimen and the strength of the graft-versus-leukemia (GVL) effect. However, it is unclear whether the sensitivity of the GVL effects differs between donor type and graft source. We retrospectively evaluated the effect of acute and chronic graft-versus-host disease (GVHD) on transplant outcomes for adults with acute leukemia ( = 6,548) between 2007 and 2017 using a Japanese database. In all analyses, we separately evaluated three distinct cohorts based on donor type [(8/8 allele-matched sibling donor, 8/8 allele-matched unrelated donor, and unrelated single-cord blood (UCB)]. The multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, showed a reductive effect of grade I-II acute GVHD on treatment failure (defined as 1-leukemia-free survival; < 0.001), overall mortality (OM; < 0.001), relapse ( < 0.001), and non-relapse mortality (NRM; < 0.001) in patients receiving from UCB. A reductive effect of limited chronic GVHD on treatment failure ( < 0.001), OM ( < 0.001), and NRM ( < 0.001) was also shown in patients receiving from UCB. However, these effects were not always shown in patients receiving from other donors. The beneficial effects of mild acute and chronic GVHD after UCB transplantation on treatment failure were noted relatively in subgroups of patients with acute myelogenous leukemia and a non-remission status. These data suggested that the development of mild GVHD could improve survival after UCB transplantation for acute leukemia.