Slightly mismatched cord blook OK for childhood leukemia

In children with acute leukemia who require transplantation, using umbilical cord blood that is human leukocyte antigens (HLA)-matched, or which has one or two mismatched antigens, produces similar 5-year leukemia-free survival rates, according to the results of a study published in the June 9 issue of the Lancet.

John E. Wagner, MD, of the University of Minnesota in Minneapolis, and colleagues analyzed data on 503 children under 16 years of age who had acute leukemia and received umbilical cord blood transplants, and 282 children with the same disease who underwent bone marrow transplantation.

Among the cord blood recipients, only 35 received HLA-matched blood, whereas 201 received blood with one mismatched antigen and 267 received blood with two mismatched antigens. Among the three groups, those who received blood with two mismatched antigens had the highest rate of transplant-related mortality, but relapse rates were lower.

In an accompanying editorial, Vanderson Rocha, MD, PhD, and Eliane Gluckman, MD, of the Hopital Saint Louis in Paris, France, add that the study data emphasizes "that an umbilical cord-blood graft should be searched for together with an unrelated allele-matched bone marrow."

Eapen M, Rubinstein P, Zhang MJ, et al. Outcomes of transplantation of unrelated donor umbilical cord blood and bone marrow in children with acute leukaemia: a comparison study. Lancet. 2007;369: 1947-1954.