Haploidentical stem cell transplantation in leukemia

In acute leukemia patients, infusing a megadose of extensively T-cell-deple ted hematopoietic stem cells after an immuno-myeloablative conditioning reg imen ensures sustained engraftment of full-haplotype mismatched transplants without graft-vs-host disease. Besides the conditioning regimen and the me gadose of stem cells donor natural killer cell alloreactivity also plays a role in facilitating engraftment and in preventing relapse. Since our first successful pilot study, our efforts have concentrated on developing new co nditioning regimens, optimizing the graft processing and improving the post -transplant immunological recovery. The results we have so far achieved in 112 very high-risk acute leukemia patients show that haploidentical transpl antation is now a clinical reality. Because virtually all patients in need of a hematopoietic stem cell transplant have a full-haplotype mismatched do nor, who is immediately available, a T-cell depleted mismatched transplant should be offered, not as a last resort, but as a viable option to high ris k acute leukemia patients who do not have, or cannot find, a matched donor. (C) 2001 Harcourt Publishers Ltd.