“The proliferative capacity of hematopoietic stem cells in cord blood is superior to that of cells in marrow or blood from adults. A 100ml unit of cord blood contains 1/10 the number of nucleated cells and progenitor cells present in 1000 ml of marrow, but because they proliferate rapidly, the stems cells in a single unit of cord blood can reconstitute the entire hematopoietic system.”

Source: New England Journal of Medicine, Vol. 344, No.24: June 14, 2001 - Hematopoietic Stem Cell Transplants Using Umbilical Cord Blood.

If the apparently low incidence of graft-versus-host disease compared to adult marrow sources is real, it may represent reduced immunocompetence of cord stem and progenitor cells. This may be a disadvantage in treating patients with cancer. It may also permit a higher incidence of second primary cancers in transplant survivors.

“The use of cord blood reduces the risk of graft-versus-host disease, the main obstacle to the success of allogeneic transplantation of hematopoietic stem cells. Cord blood is an attractive source of stem cells, because the reduced risk of graft versus-host disease should make possible less stringent criteria for HLA matching.”

“Most studies in children with malignant or nonmalignant hematologic diseases have shown that long-term survival after transplantation of cord blood is similar or superior to survival after transplantation of marrow when the donor is a sibling.”

Source: New England Journal of Medicine, Vol.344, No.24: June 14, 2001 - Hematopoietic Stem Cell Transplants Using Umbilical Cord Blood.

“Results in children have clearly shown that the number of nucleated cells in the infused cord blood influences the speed of recovery of neutrophils and platelets after myeloablative chemotherapy. The optimal dose is about 2x10⁷ nucleated cells per kilogram of body weight, which raises the question of feasibility of transplantation of cord blood in adults.”

“The age and weight of the recipient are not an obstacle, as long as the unit of cord blood contains more than 2x10⁷ nucleated cells per kilogram of the recipients weight at time of collection.”

Source: New England Journal of Medicine, Vol. 344, No.24 : June 14, 2001
Hematopoietic Stem Cell Transplants Using Umbilical Cord Blood.

“Information on effects of longer term storage is important for cord blood banking. As part of our past efforts to evaluate feasibility of cryopreserving and using cord blood for transplantation (Broxmeyer et al 1989, PNAS 86:3828) we maintained stored frozen Cord Blood samples with pre-freeze information. This allowed us to quantitate efficiency of recovery of viable hematopoietic progenitor cells from cord blood stored frozen 15 years ago.” “The results demonstrated that human cord blood hematopoietic stem cells and hematopoietic progenitor cells with high proliferative can be stored frozen for over 15 years and retrieved in viable form.”

Source: Blood Vol. 98 (Supplement 1) pg 183a; Abstract # 768. [Abstract] – High Efficiency Recovery of Hematopoietic Progenitor Cells with Extensive Proliferative and Ex Vivo Expansion Activity and of Hematopoietic Stem Cells with NOD/SCID Mouse Repopulating Ability from Human Cord Blood Storage frozen for 15 years.”