Filtration Method Developed for Cord Blood

A novel filtration system using a nonchemical-coated and nonwoven polyester fabric filter, which traps cells through affinity, has been developed for cord blood.

Cord blood (CB) is being increasingly used as a source of hematopoietic stem cells for transplantation to treat diseases of the blood and immune systems, and there is an urgent need to expand CB banking worldwide.

Scientists at Kyushu University School of Medical Science (Fukuoka, Japan) developed a polyester fabric filter specifically for CB, which traps cells and does not require centrifugation or potentially toxic chemicals. Normally CB processing requires costly machinery or a clean room that hampers wider application of cord blood transplantation (CBT) particularly in the developing countries.

The collection efficacy was calculated by counting total nucleated cells (TNCs) using an automated hematology analyzer KX-21 (Sysmex; Kobe, Japan) or ABX Pentra hematology analyzer (Horiba; Kyoto, Japan). The red blood cell (RBC) compartment combines the RBCs and the nucleated red cells. The number of mononuclear cells (MNCs) or polymorphonuclear cells (PMNs) was calculated as the product of TNC count, and the percentage of each population analyzed by FACSCanto flow cytometry (BD Biosciences; San Jose, CA, USA). Collection efficacy was defined as the ratio of cell number in the collected fraction relative to the introduced cord blood.

The loss of TNCs, MNCs, and PMNs was less than 5%. The loss of CD34+ cells was only 0.5%, indicating the minimal loss of nucleated cells and CD34+ cells during this process. On the other hand, 84.8% of RBCs and 61.0% of platelets were in the flow-through fraction. These data indicated that the device could trap nucleated cells and remove RBCs and platelets efficiently. Therefore cell processing with the device resulted in minimum cell loss of total cells and CD34+ cells, without impairing the ability of CD34+ cells to engraft and differentiate both in vivo and in vitro.

The authors concluded that CB processing with the device is simple, cost-effective, and nontoxic without requiring costly equipment will facilitate international CB banking. This will help in meeting the increasing worldwide demand for CB for allogeneic hematopoietic stem cell transplantation. The study was published on December 14, 2012, in the International Journal of Laboratory Hematology.

Related Links:
Kyushu University School of Medical Science
Sysmex
Horiba