[Analysis of 66 cases received hematopoietic stem cell transplantation from unrelated donors]

To improve the outcome of hematopoietic stem cell transplantation from unrelated donors.

Sixty-six patients with hematological diseases (40 cases of acute leukemia, 24 chronic myeloid leukemia, and one each severe aplastic anemia and beta-thalassemia) received bone marrow (BMT, n = 48) or peripheral blood stem cell transplantation (PBSCT, n = 18) from HLA-compatible unrelated donors after BUCY or TBI conditioning. Forty patients received longer and intensive GVHD prophylaxis (cyclosporin A from day -10 combined with mycophenolate mofetil).

Sixty-four patients achieved sustained donor engraftment. The median time of leukocyte engraftment was 15 days, being significantly earlier in PBSCT group compared with BMT group (12 vs 16 days, P = 0.002). The cumulative incidence rates of grades I-II and III-IV acute GVHD at day 100 were 57.15% and 32.25%, respectively. Chronic GVHD was seen in 21 of the 36 evaluable cases and ten of them were extensive type. Six patients relapsed and 27 dead, the overall survival at 5 years was 52.91%. The COX method analysis showed that HLA-compatible level and source of graft affected the incidence of aGVHD. The patients transplanted from HLA-matched donor with high resolution and PBSCT had the less probability for aGVHD. Patients without GVHD or with longer and intensive GVHD prophylaxis had significantly improved OS.

The key to improvement the outcome of HCT from unrelated donor is to reduce the incidence and severity of aGVHD by selecting the HLA-matched donor, intensifying the immunosuppression at the early stage of transplantation.