Non-total body irradiation containing preparative regimen in alternative donor bone marrow transplantation for severe aplastic anemia

Using non-total body irradiation (TBI) containing preparative regimens, 13 patients with severe aplastic anemia (SAA) were transplanted from an alternative donor in a single institute. In total, 12 donors were unrelated volunteers and one was an HLA one-locus mismatched sibling. Median time from diagnosis of SAA to bone marrow transplantation (BMT) was 10.1 months (range, 1.6-180.1). Nine patients had received immunosuppressive treatment with ATG before BMT, while four had not. Preparative regimens consisted of cyclophosphamide plus ATG in nine patients, cyclophosphamide plus fludarabine in two patients, and cyclophosphamide plus fludarabine plus ATG in two patients. All patients received non-T-cell depleted bone marrow from the donor. Cyclosporine plus methotrexate were given for GVHD prophylaxis. All patients engrafted on a median of day 21 (range, 15-27). Grade III-IV acute GVHD developed in three (23%) of 13 patients and extensive chronic GVHD in four (31%) of 12 evaluable patients. With a median follow-up duration of 1138 days (range, 118-1553), 10 patients are alive with durable engraftment showing 74.6% (95% confidence interval, 49.5-99.7%) of survival rate. Cause of the deaths was CNS bleeding in one and chronic GVHD in two. In conclusion, non-TBI containing preparative regimen could ensure durable engraftment in alternative donor BMT for SAA and showed promising results.