The IMPORTANCE of YOUR FAMILY'S STEM CELLS

Haemopoietic stem cell transplantation for children in Australia and New Zealand, 1998–2006:a report on behalf of the Australasian Bone Marrow Transplant Recipient Registry and the Australian and New Zealand Children’s Haematology Oncology Group.

This above study is an important milestone epidemiological study in CHILDREN published in the Medical Journal of Australia in February 2009. It gives us invaluable information and insight on the source of stem cells used (from bone marrow, peripheral blood or cord blood), their origin (autologous: own; related allogeneic: matched siblings; unrelated allogeneic: matched strangers) and on the indications for which a bone marrow transplantation has been performed. Moreover, it studies the important aspect of Transplant Related Mortality (TRM). Few of us actually have insight in those issues and understanding them will aid in deciding whether to keep your own stem cells or not.

Let's have a look!

Over a period of 9 years (1998-2006) 1,259 BMTs were performed in children in Australia and New Zealand, of which 41% were autologous (used the child's own stem cells from bone marrow or peripheral blood) while 59% were allogeneic (someone else's stem cells). Of the latter 40% were from a matched sibling (23.6% of the total) and 60% from matched strangers. That brings the total number of children ultimately finding stem cells from themselves or within their immediate family up to 65% while the remaining 35% had to depend on matched strangers to donate or on donated cord blood. It means that at the end of the day when a child was ill and in need of stem cells for BMT, then those were found in 65% of the cases from the child or the immediate family. More important is that the stem cells used were bone marrow or peripheral blood stem cells and that means that in that perilous period of a family's and a child's life an extra burden in collecting stem cells from the bone marrow or peripheral blood is added on top of all stress that is already evident. One can also speculate how this additional psychological stress and wait may impact on disease progression. If those families had been informed about cord blood stem cells and had kept their children's cord blood stem cells then those little frozen bags would have been stored and waiting to be used at any given time! Furthermore, the importance of using your own or those of a matched immediate relative is reflected in the TRM; Transplant Related Mortality is 22-28% when one receives a matched stranger's stem cells and only 5-7% if one receives their own or a matched sibling's stem cells.

The other important issue is that the matched stranger stem cells come nowadays more from donated cord blood stem cells than bone marrow/peripheral blood. In the latest years more than half, almost 2/3, come from donated cord blood and subsequently since cord blood stem cells are immunologically naïve and cause 30% less rejections, more mismatched transplants have been performed. One can speculate if this is the reason for the difference in Transplant Related Mortality that is higher in mismatched stem cells from strangers. So, if one would not keep for own use one should definitely donate for public use!

In the words of the authors of the study “Autologous BMT has an important role in a range of childhood cancers, including neuroblastoma, medulloblastoma, Ewing sarcoma/PNET, Hodgkin lymphoma and non-Hodgkin lymphoma” while “allogeneic (matched siblings or strangers) transplantation is most frequently offered to children with high-risk and relapsed leukaemias, myelodysplastic syndromes, aplastic anaemia, congenital bone marrow failure syndromes, thalassaemia major, sickle cell anaemia and various inborn errors of metabolism”.

The results of this study are similar to a previous one published in the Biology of Blood and Marrow Transplantation in 2007, entitled “Haematopoietic Stem Cell Transplantation in Australia and New Zealand, 1992-2004”. In this study that encompasses all transplantations in Australia and New Zealand both in adults and children, the same trend is evident and even more pronounced. That is, when you need stem cells you find them in you or in your immediate family! In2004 alone, 68% of the patients used their own stem cells (889/1,313) while another 19% received stem cells from matched siblings and only 13% managed to find stem cells from matched strangers. That means that a total of 87% found the needed stem cells in themselves or within the immediate family! Importantly, Transplant Related Mortality was 8.1% for stem cells from strangers compared 1.1% for own stem cells! One can also in the adult cases speculate how the effect of the additional psychological stress of stem cell collection and/or wait to find stem cells from strangers may impact on disease progression. If those families had kept their own peripheral blood stem cells then those little frozen bags would then have been stored and waiting to be used at any given time!

Cord blood stem cells and peripheral blood stem cells have an immense importance be it for a family's own use or for complete strangers where anyone can offer the hope of life. Regardless the use or the intention, those stem cells must be kept for their purpose to be fulfilled! Do not let them go wasted!

References

1. Moore AS, Shaw PJ, Hallahan AR, Carter TL, Kilo T, Nivison-Smith I, O'Brien TA, 
Tapp H, Teague L, Wilson SR, Tiedemann K. Haemopoietic stem cell transplantation
for children in Australia and New Zealand, 1998-2006: a report on behalf of the
Australasian Bone Marrow Transplant Recipient Registry and the Australian and
New Zealand Children's Haematology Oncology Group. Med J Aust 2009; 190(3): 121-5  

2. Nivison-Smith I, Bradstock KF, Dodds AJ, Hawkins PA, Ma DD, Moore JJ,
Simpson JM, Szer J.Hematopoietic stem cell transplantation in Australia and New Zealand,
1992-2004. Biol Blood Marrow Transplant 2007; 13(8): 905-12