Background: For most conditions amenable to bone-marrow transplantation, grafts from HLA-matched but unrelated donors have yielded poorer results than those obtained from matched-sibling donors. We assessed this pattern in the light of improvements in donor selection and post-transplant supportive care.
Methods: We reviewed transplant outcome in 103 consecutive patients with childhood leukaemia who underwent allogeneic bone-marrow transplantation with HLA-matched sibling marrow (n = 52) or matched unrelated donor marrow (n = 51) between May, 1990, and March, 1996, at St Jude Children's Research Hospital.
Findings: Analysis of engraftment, frequency of procedure-related complications, and disease-free survival revealed no advantage from use of matched-sibling marrow. The 2-year disease-free survival estimate for standard-risk recipients of matched-sibling marrow was 81 [8.1]% compared with 73 [12.1]% in the unrelated donor marrow group (p = 0.77). In the high-risk category, patients with a matched-sibling donor had a 2-year disease-free survival of 31 [11.6]%, compared with 32 [15.1]% among recipients of matched unrelated donor marrow (p = 0.87).
Interpretation: We believe this improved result with unrelated donor marrow is a consequence of recent innovations in histocompatibility matching, prevention of graft-versus-host disease (GvHD), and antiviral prophylaxis. We suggest that such grafts can now be used in patients at both standard and high risk without compromising treatment outcome.