Anti-Thymocyte-Globulin as part of the preparative regimen prevents graft failure and severe Graft versus Host disease (GvHD) in allogeneic stem celltransplantation from unrelated donors

To reduce the incidence of GvHD and the rate of graft failure in unrelated stem cell transplantation, we incorporate anti-thymocyte globulin in the pr eparative regimen in 98 patients with hematological or inherited storage di sease. The median age was 32 years (range: 1-56) and 84 patients underwent transplantation from HLA-A,-B and DR identical donor, while in 14 patients the donor were mismatched either in HLA- A, -B or -DR locus. Only one patient with chronic myelocytic leukemia (CML) and blast crisis ha d a primary graft failure (1%). Grade II-IV acute GVHD occurred in 37 patie nts (37%), grade III/IV GVHD developed in 15 patients (15%). Chronic GvHD w as observed in 29%, and only 12 patients had extensive GVHD (17%). After a median follow-up of 34 months (range, 9-90), the estimated overall survival at 3 years for all patients is 58% (CI 95%: 48%-68%), and the estimated di sease-free survival at 3 years is 49% (CI 95%: 38%-60%). For patients with CML transplanted in first chronic phase or accelerated phase (n=40), the es timated overall survival at 3 pears is 70% (CI 95%: 56%-84%), and the estim ated disease-free survival at 3 years is 58% (CI 95%: 17%-85%). ATG in unre lated stem cell transplantation reduces the risk of severe acute and chroni c GVHD and of graft failure without an obvious increase of severe infection . Further follow-up is mandatory to determine the incidence of late relapse .