Bone marrow transplantation in thalassemia major patients using "short" anti-thymocyte globulin therapy in Shiraz, Southern Iran.

Allogeneic bone marrow transplantation (BMT) was performed on 113 Iranian transfusion-dependent thalassemia major patients from May 1993 through September 2003. To have at least 2 years follow-up, we report BMT on 90 patients transplanted up to December 2001. The donors were human leukocyte antigen (HLA)-identical, mixed lymphocyte culture (MLC)-nonreactive siblings (n = 74) on parents (n = 6); HLA-identical MLC-reactive siblings (n = 5) or parents (n = 1); and one HLA antigen-mismatched sibling (n = 4). The induction regimen in 11 patients was oral busulfan (BU) (14 mg/kg) and IV cyclophosphamide (CY; 200 mg/kg); in fifteen patients it was BU (15 mg/kg) and cyclophosphamide (CY; 200 mg/kg); in 47 patients, BU (15 mg/kg), CY (200 mg/kg), and short course of anti-thymocyte globulin (ATG, horse; 40 mg/kg including 10 mg/kg on days -2, -1, +1, +2); and in 15 patients, BU (15 mg/kg) CY (200 mg/kg), and ATG (60 to 100 mg/kg; 10 mg/kg at 3 to 5 days before and after BMT). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and prednisolone. The group who received BU (14 mg/kg) and CY (200 mg/kg), as compared to the group receiving BU (15 mg/kg) and CY (200 mg/kg), was of younger age and lower risk; median age 7 versus 10 years, and 46% versus 7% in Lucarelli's risk group class I (the best prognostic group), respectively. These patients showed a lower disease-free survival (DFS), namely 64% versus 73%, with a follow up of 2 to 10.5 years. Thus from 9.5 years ago, our standard protocol for BU has been 15 mg/kg. The group who received "short" ATG (40 mg/kg), BU (15 mg/kg), and CY (200 mg/kg) showed almost the same outcome as the group who received a higher dose of ATG (60 to 100 mg/kg), namely DFS 72% versus 73%, respectively, despite the fact that half of both groups were included in the Lucarelli's risk group class III (the worst prognostic group) 49% versus 53%. We showed the same DFS for the patients who received BU (15 mg/kg), CY (200 mg/kg), and no ATG compared with the ATG group (73% vs 72%), but 27% of the group without ATG developed grade IV acute GVHD and 54% developed chronic GVHD. In the group with short ATG, 15% and 17% of patients developed grade IV acute and chronic GVHD, respectively. There was no significant difference for falls in platelets and white blood cell or engraftment days and the number of packed red blood cell transfusions among the groups. The median hospital stay was longer for the group with BU (15 mg/kg), CY (200 mg/kg) namely 81 versus 61 to 65 days. Second bone marrow infusions were needed in 6% and 20% of patients who received ATG doses of (40 versus 60 to 100 mg/kg; respectively (1 to 2 month post-BMT). BU at a dose of 15 mg/kg was more effective than 14 mg/kg BU for its myeloablative properties. By adding "short" ATG course to the conditioning regimen, the incidence of grade IV acute and chronic GVHD was reduced in thalassemic patients, especially when an HLA disparity was present.