This is a phase II, single-center study to evaluate the efficacy of a novel cytoreductive regimen followed by CD34+E- selected T cell depleted allogeneic stem cell (or soybean agglutinated and E-rosetted BM) transplant as treatment for patients with acute and chronic leukemias, lymphoma and myelodysplstic syndrome/PNH. The impact of the change in conditioning regimen and use of CD34-selected T cell depleted PBSCs on transplanted related morbidity and mortality and disease free survival will be assessed.

The purpose of this study is: (1) to try to kill any cancer or precancer cells that are in your body, and to reduce the side effects of a transplant, which we have seen in our previous studies, (2) to see if this treatment with a new recipe of radiation and chemotherapy can suppress your immune system enough for the stem cells to 'take' and grow, (3) to see if the specially prepared stem cells can grow in you without a problem called graft-versus-host disease (GvHD) occurring.

One of the major side effects of any stem cell transplant is a condition known as graft vs. host disease or GVHD. GVHD is an immune reaction caused by certain cells from the transplanted stem cells called T-lymphocytes (or T-cells). The T-cells from your donor may see your organs as foreign and attack them. New ways to remove the T-cells from the stem cells before the transplant are being used to try and prevent GVHD. In some studies, the removal of T-cells from the stem cells has been successful for many patients in preventing both short-term (acute) and long-term (chronic) forms of GVHD. However, the removal of T-cells may increase the chance that the new bone marrow developing from the stem cells will be rejected or will not function well. Rejection of the transplant means that some of your own cells have survived the chemo and radiation therapy, and are attacking the new bone marrow cells. This condition can be lifethreatening because of an increased risk of infections and bleeding and would require your getting more treatment and additional stem cells. Studies like this one are designed to find better ways to avoid GVHD without increasing the risk of other problems such as graft rejection.

Inclusion Criteria:

• Histologically proven acute or chronic leukemia, non Hodgkins and lymphoblastic lymphoma or myelodysplastic syndrome
• HLA 6/6 or 5/6 antigen matched related or unrelated donor
• creatinine = normal or if not, CrCl > 60 ml/min/1.73ml
• total bilirubin < 2.5, AST < 2xnl, cardiac function > 50%
• pulmonary function - asymptomatic or if not DLCO > %50% (corrected for Hgb)
• Karnofsky performance status > 70%
• negative pregnancy test (where applicable)
• signed informed consent of patient and donor.

Exclusion Criteria:

• Pregnancy or lactation
• unwillingness to comply with protocol treatment or follow-up
• uncontrolled infection
• HIV or HTLV positivity
• active CNS/skin disease