Volume Reduction in Routine Cord Blood Banking

Umbilical cord blood (UCB) is an alternative source of haematopoietic progenitors for transplantation in the treatment of haematological malignancies, marrow failure, immunodeficiencies, hemoglobinopathies and inherited metabolic diseases. It has greatly contributed to increase the feasibility to transplantation for many patients in need. To date, more than 20,000 UCB transplants have been performed on children and adults, and more than 400,000 UCB units are available in more than 50 public CB banks. One of the most important objectives of banks is to cryopreserve and store high quality UCB units. Volume reduction is a usual process in cord blood banking that has some advantages as reducing the storage space and the DMSO quantity in final product. Volume reduction methodology must guarantee high cell recovery and red blood cell (RBC) depletion by reducing the UCB units to a standard volume. Hydroxyethyl starch (HES) sedimentation was the first method developed for this purpose by the New York Cord Blood Bank and implemented in many banks worldwide. The semi-automated top and bottom system, usually used for blood fractionation was further developed to simplify and short the process. Later, automatic devices as SEPAX and AXP have been developed in last years specifically for UCB volume reduction purpose. This review critically analyses the advantages and disadvantages of the different procedures. All of them have been used in Valencia Cord Blood Bank along 10 years. In general, automatic devices are preferred because of compliance with cGTP, closed systems, higher reproducibility and less influence of technician.