Background

Human umbilical cord blood is a rich source of stem cells that are present in bone marrow and that have been used successfully to treat a variety of hematologic diseases. Stem cells divide to make new RBCs, WBCs, and platelets. In persons with hematologic disease, stem cells in cord blood restore marrow function after chemotherapy. To date, more than 1,000 cord blood transplants have been performed worldwide from both HLA-matched and HLA-mismatched donors. The suc-cess of these transplants has been attributed to the following factors: maternal T-cell contamination is below the level of detection by DNA techniques, microbial contamination occurs with low fre-quency with current collection methods, and cor