We have analyzed 2,002 patients grafted in Europe between 1976 and 1998 from an identical twin (n = 34), from an HLA-identical sibling (n = 1,699) or from an alternative donor (n = 269), which included unrelated and family mismatched donors. The proportions of patients surviving in these three groups are, respectively, 91, 66 and 37%: major causes of failure were acute graft-versus host disease (GvHD) (11%), infection (12%), pneumonitis (4%), rejection (4%). In multivariate Cox analysis, factors predicting outcome were patient's age (p < 0.0001), donor type (p < 0.0001), interval between diagnosis and bone marrow transplantation (BMT) (p < 0.0005), year of BMT (p = 0.0005) and female donor for a male recipient (p = 0.02). Patients were then divided in two groups according to the year of BMT: up to or after 1990. The overall death rate dropped from 43 to 24% (p < 0.00001). Improvements were seen mostly for grafts from identical siblings (from 54 to 75%, p < 0.0001), and less so for alternative-donor grafts (from 28 to 35%; p = 0.07). Major changes have occurred in the BMT protocol: decreasing use of radiotherapy in the conditioning regimen (from 35 to 24%; p < 0.0001) and increasing use of cyclosporin (with or without methotrexate) for GvHD prophylaxis (from 70 to 98%; p < 0.0001). In conclusion, the outcome of allogeneic BMT for patients with severe aplastic anemia has considerably improved over the past two decades: young patients, grafted early after diagnosis from an identical sibling, have currently an over 80% chance of long-term survival. Transplants from twins are very successful as well. The risk of complications with alternative donor transplants is still high.
Copyright 2000 S. Karger AG, Basel