Unrelated Double Umbilical Cord Blood Units Transplantation

Inclusion Criteria: * Hematologically \& Histologically confirmed acute lymphoblastic or acute and chronic myeloid leukemia in Remission * Aged 1 year to 50 years * Absence of HLA compatible related or other related donor. * Availability of suitable UCB units. * karnofsky performance score (\> 12 yr) or lansky play performance(\<12 yr) : 80- 100 * Adequate renal function defined as:Serum creatinine \<1.5 x normal, * Adequate liver function defined as:Total bilirubin \<1.5 x normal, or SGOT (AST) or SGPT (ALT) \<3.0 x normal * Adequate cardiac function defined as: Ejection fraction \>50% by echocardiogram. * Adequate pulmonary function defined as:Uncorrected DLCO 50% by pulmonary function test.For children who are uncooperative, no evidence of dyspnea at rest, no exercise intolerance, and a pulse oximetry \>94% on room air Exclusion Criteria: * Age: \< 1year or \> 50 year * Patients with an available 5-6/6 HLA-A, -B, -DRB1 matched sibling or other related donor * karnofsky performance score (\> 12 yr) or lansky play performance(\<12 yr) \< 80 * HIV positive patients. * Female patients who are pregnant or breast feeding * Life expectancy severely limited by diseases of vital organs other than the disease indication for transplant * Serious concurrent untreated infection e.g. active tuberculosis, mycoses or viral infection * Serious psychiatric/ psychological disorders * Absence of /inability to provide informed consent * Clinical or Paraclinical evidence of CNS or PNS involvement