Objectives: Acute graft-versus-host-disease (aGvHD) is a major cause of mortality after allogeneic hematopoietic cell transplantation (alloHCT). The goal of this study was to evaluate the incidence and risk factors for this complication. Methods: 330 consecutive patients (183 male and 147 female), aged 29 (10-56) years, treated with alloHCT in a single center between 1992- 2003 were included in the analysis. AlloHCT was performed after myeloablative conditioning from either related donor (rel-HCT) (n=223) or unrelated voulnteer (URD-HCT) (n= 107). GVHD prophylaxis consisted of cyclosporin, methotrexate +/- prednisolone. Results: Cumulative incidence of grade II-IV and grade III-IV aGvHD equaled 31% and 17%, respectively. In multivariate analysis the following factors were associated with increased risk of grade II-IV aGvHD: the diagnosis of chronic myeloid leukemia (CML) or myelodysplastic syndrome (MDS) (vs. other diagnoses), URD-HCT (vs. Rel-HCT), years of alloHCT 1992-200 I (vs. 2002-2003), donor age 35 years. and CD34+ cell dose 4.0 x I0 ^6/kg. Increased risk of grade III-IV aGVHD was associated with: the use of prednisolone for aGvHD prophylaxis, the diagnosis of CML or MDS, and CD3+ cell dose ;?:IOO xI06/kg. Conclusions: Incidence of aGvHD depends on various recipient-, donor-, and procedure-related factors. This should be taken into account when planning treatment for every individual patient.

Keywords: Acute Graft-versus-Host-Disease, allogeneic hematopoietic cell transplantation