GVHD prophylaxis will be achieved through positive selection for CD34 resulting in > 3 log T cell depletion. Previous reports have indicated that there is a low frequency of severe (Grade II/IV) GvHD after haploidentical transplants if recipients receive stem cell populations containing <5 x 10e4 CD3 positive T cells. We hope to achieve such levels with our CD34 enrichment protocol. However, pharmacologic prophylaxis will be added if the CD34 selected product contains more than 5 x 10e4 CD3+ve T cells/kg recipient weight. In addition, Campath 1H persists in the recipient circulation through the immediate transplant period and will contribute anti-GVHD activity, in vivo.