Author:

Keywords:

Adolescent, Adult, Antigens, CD34, Blood Transfusion, Fetal Blood, Hematologic Neoplasms, Histocompatibility Testing, Humans, Infant, Newborn, Middle Aged, Stem Cell Transplantation, Transplantation Chimera, Treatment Outcome, Science & Technology, Life Sciences & Biomedicine, Hematology, BONE-MARROW TRANSPLANT, HEMATOPOIETIC STEM-CELLS, UNRELATED DONORS, PLACENTAL-BLOOD, QUANTITATIVE-DETERMINATION, ACUTE-LEUKEMIA, PAIR ANALYSIS, RECIPIENTS, SURVIVAL, OUTCOMES, 1102 Cardiorespiratory Medicine and Haematology, 1103 Clinical Sciences, 1114 Paediatrics and Reproductive Medicine, Immunology, 3101 Biochemistry and cell biology, 3201 Cardiovascular medicine and haematology, 3213 Paediatrics

Abstract:

Limited umbilical cord blood (UCB) cell dose compromises the outcome of adult UCB transplantation. Therefore, to augment graft cell dose, we evaluated the safety of the combined transplantation of 2 partially human leukocyte antigen (HLA)-matched UCB units. Twenty-three patients with high-risk hematologic malignancy (median age, 24 years; range, 13-53 years) received 2 UCB units (median infused dose, 3.5 x 10(7) nucleated cell [NC]/kg; range, 1.1-6.3 x 10(7) NC/kg) after myeloablative conditioning. All evaluable patients (n = 21) engrafted at a median of 23 days (range, 15-41 days). At day 21, engraftment was derived from both donors in 24% of patients and a single donor in 76% of patients, with 1 unit predominating in all patients by day 100. Although neither nucleated or CD34(+) cell doses nor HLA-match predicted which unit would predominate, the predominating unit had a significantly higher CD3(+) dose (P < .01). Incidences of grades II-IV and III-IV acute GVHD were 65% (95% confidence interval [CI], 42%-88%) and 13% (95% CI, 0%-26%), respectively. Disease-free survival was 57% (95% CI, 35%-79%) at 1 year, with 72% (95% CI, 49%-95%) of patients alive if they received transplants while in remission. Therefore, transplantation of 2 partially HLA-matched UCB units is safe, and may overcome the cell-dose barrier that limits the use of UCB in many adults and adolescents.