ERYTHROCYTE-DEPLETED ALLOGENEIC HUMAN UMBILICAL-CORD BLOOD TRANSPLANTATION

Cord blood is a recently recognized source of hematopoietic stem cells . It can be employed successfully to reconstitute hematopoiesis follow ing allogeneic transplantation. One current drawback of cord blood as a treatment has been a risk of transfusion reactions attributable to A BO blood group mismatch, Removal of red cells from the cord blood has led to reduction of the stem cells by 30-50%, In this paper we report red cell depletion by a method that employs 3% gelatin to effectively sediment the erythrocytes and selectively deplete red cells but permit s 94% recovery of nucleated cells and enrichment of colony-forming cel ls by granulocyte-macrophage colony-forming units, erythrocyte burst-f orming units, and granulocyte-macrophage-megakaryocyte colony-forming units in the cord blood preparation, This technique has been employed in our study to remove red cells from the cord blood of a male infant delivered by cesarean section, which has permitted treatment of a fema le sibling suffering from leukemia, The recipient was 8 years old and weighed 36.7/kg, Complete HLA identity between the two siblings was es tablished, A cord blood cell transplant of cryopreserved and later tha wed cells (4 x 10(7) nucleated cells per kilogram) was administered to the patient after intensive myeloablative chemotherapy, The patient e xhibited a prompt hematologic recovery (absolute neutrophil count >500 by day 31, 100% male cells in bone marrow and peripheral blood by day 25) and has experienced a 13-month disease-free survival to date. The se findings suggest that this method of gelatin separation of erythroc ytes represents a simple and effective technique that can be used for reducing cord blood red cells and at the same time permit use of the r emaining stem cells for transplantation and for the treatment of eithe r malignant or nonmalignant disorders,