The Functions of Cord Blood Stem Cells

The growing interest in cord blood storage is underpinned by the value of two types of stem cells derived from cord blood – the blood forming hematopoietic stem cells (HSC) and the multipotent mesenchymal stem cells (MSC).

Hematopoietic stem cells (HSC)
In the human body, new blood cells are constantly produced to replenish mature cells which are routinely lost and destroyed. This process of blood cell generation is called hematopoiesis and it takes place largely in bone marrow.

Historically, transplant of HSC is the most common treatment for blood cancer patients. There are three sources for collecting HSC for transplantation: bone marrow, peripheral blood, and cord blood. Before Broxmeyer discovered the hematopoietic property of cord blood, bone marrow transplants were most commonly used for the replenishment of blood cells.

To date, one half of all transplants from unrelated donors in children now use cord blood in the United States [1]. In Japan, this is true for adults as well [2]. Cord blood transplant not only provides an alternate option to bone marrow transplant, but more important, it has offered new hope for patients who had not been able to find a bone marrow match.

Mesenchymal stem cells (MSC)
In recent years, MSC were reported to have been isolated from cord blood and expanded under specific conditions [3]. MSC is a multipotent stem cell that can differentiate into a variety of cell types in the laboratory, including fat cells, cartilage, bone, tendon and ligaments, muscles cells, skin cells and even nerve cells [4].

Unlike other adult stem cells, MSC can be obtained in appropriate quantities for clinical applications, thus making it the perfect candidate for tissue repair [5].

[1] “Cord blood can save lives” www.nationalcordbloodprogram.org (accessed 13 June 2007).
[2] Ibid.
[3] Bieback K et al.(2004), Stem Cells. 22(4):625-34
[4] S Kadereit, “Adult Stem Cells” http://www.isscr.org/public/adultstemcells.htm, (accessed 20 June 2007).
[5] Ibid.