Superior Graft-versus-Host Disease-Free Relapse-Free Survival in Matched Unrelated Donor Hematopoietic Stem Cell Transplantation with Anti-Thymocyte Globulin (ATG) Compared to Matched Related Donor without ATG

The use of anti-T cell globulin (ATG) in allogeneic stem cell transplantation with matched unrelated donors (MUDs) is considered standard of care in many transplant centers, as these patients are at higher risk of developing acute and chronic graft-versus-host disease (GVHD). Several publications have reported reduced incidence of chronic GVHD compared to matched related donors (MRDs). This may support the idea of introducing ATG in prospective clinical trials, also in MRDs, in an effort to reduce the long-term complications with moderate and severe GVHD. We retrospectively analyzed 169 patients, in whom ATG was given to patients who underwent transplantation with MUDs (n = 124) and not MRDs (n = 45). The incidence acute GVHD II to IV and III to IV was significantly lower in the MUD group compared to the MRD group (28.2% versus 51.3% and 8.1% versus 24.7%). Extensive chronic GVHD incidence was 5% versus 40%. Our results further support the rationale for examining the efficacy of ATG in MRDs in prospective randomized trials