Produced by Anna Uridge 42003113
The outcome of hematopoietic stem cell transplantation (bone marrow transplantation) has significantly improved since the 1950s due to the emergence of new antiviral drugs and improved testing for human leukocyte antigen (HLA) matches. Additionally, there have recently been advances in the field of bone marrow transplantations as umbilical cord blood (UCB) can potentially be used as another source for these stem cells. There would be a number of advantages for using UCB compared to the previous methods of finding HLA-matched donors, as the cells are readily available and are easy to obtain.
Before the emergence of UCB patients could only source the hematopoietic stem cells with a HLA-match from a sibling or through unrelated volunteers. Having a sibling as a donor is the preferable option of the two, as there is a stronger graft-versus leukaemia effect, the donor is readily available, and there is the option of collecting additional cells for future immunotherapy if required. However, approximately one-third of patients actually have a HLA-matched sibling donor, and only 60% of patients are able to find a potential donor [1].
This situation worsens when an unrelated volunteer is unavailable, when a person has a rare HLA type, cannot find a donor, or passes away due to the disease whilst searching for a donor. After transplantation, patients are treated with a course of immunosuppressant and anti-infective drugs, as a method of trying to prevent graft-versus-host disease (where the body’s immune system attacks the cells as it recognises them as foreign), graft rejection and viral infections after transplantation. The two most common types of infection after transplantation is Cytomegavirus and Epstein-Barr virus. Treatment for these viral infections is then based on the detection of viral DNA by polymerase chain reaction (PCR).
Recent studies by Eapen and colleagues, found that the 5-year disease-free survival (DFS) after 6/6 matched umbilical cord blood transplantation (UCBT) was significantly greater to that compared to an 8/8 allele matched unrelated bone marrow transplantation in patients under the age of 16 [1]. Eapen also found that the DFS after 5/6 or 4/6 matched UCBT was equivalent to an 8/8 allele matched unrelated bone marrow transplantation [1]. This finding supports the ideology of using UCBT as the first choice in treating children with leukaemia [1].
Thus, there are a number of advantages of using UCBT compared to current methods, including the immediate availability of UCB and the cells are easy to obtain. Individual tailored therapy will be an option one day as scientific advancements continue to improve.
References
- Huang, X 2008, ‘Advance in hematopoietic stem cells transplantation for leukemia’, Chinese Medical Journal, no. 121 (18), p. 1763
- CellSafe International 2008, How do we collect cord blood cells, digital image of umbilical cord collection, viewed 1 May 2009, http://www.cellsafegroup.com/newwebsite/diagram.htm
