Oklahoma has state legislation around cord blood education that follows the Institute of Medicine guidelines and mandates/encourages physicians to educate expectant parents about ALL forms of cord blood banking. The Oklahoma bill was enacted 15 May 2008 and became effective 1 July 2008.
- How much cord blood is needed for a transplant?
The crucial thing is not the volume of the cord blood collection, but the number of stem cells it contains. Transplant doctors develop recommendations based on the Total Nucleated Cell count, or TNC, because it is the easiest measure to reproduce between different labs. For treating cancer, the transplant dose should be at least 25 million TNC per kilogram of patient body weight (1 kilogram equals 2.2 pounds). The average cord blood collection holds 8.6 million TNC per mL. Thus, the optimal transplant dose requires harvesting:
1.3 mL of cord blood for every pound of patient weight, -or-
2.9 mL of cord blood for every kg of patient weight
However, as more transplant centers are adopting the practice of giving adult patients "double cord blood transplants" with two cord blood units, it is less critical for both units to have adequate cell dose.
Reed, W et al., Blood 2003;101(1):351
Barker, JN et al., Blood 2005;105:1343-1347
Eapen, M et al. Lancet 2007;369:1947-54
Rocha & Gluckman Brit. J. Haematology 2008;147:262-274
Delaney, C et al., Brit. J. Haematology 2009;147:207-216
Michallet et al. 2010 Blood 2010;116:Abstract#361
- What are TNC, MNC, CD34+, and CFU, and why should I care?
These are all ways of counting cell types, and they tell you whether or not your cord blood collection has lots of stem cells and if they are healthy.
Stem cells happen to be Mono-Nuclear Cells or MNC: when you look at them under a microscope there is only one nucleus. Unfortunately, one of the most difficult aspects of stem cell biology is that you can't identify a stem cell just by looking at it. There are other types of blood cells which are also MNC, such as nucleated red blood cells. The only proof that a cell is a stem cell comes from how it behaves when it multiplies.
Scientists have worked for years to develop various chemical stains which have a high affinity for stem cells. The best known marker for blood-forming stem cells is that they test positive for CD34, a protein found on the surface of stem cells. But, CD34+ counts are not an accurate measure of stem cells: CD34+ results vary between labs, they can vary within a single lab, and only 1-2% of the MNC that have CD34+ are actually stem cells.
The Total Nucleated Cell count or TNC is the test most often reported as a measure of the cell count after cord blood processing. The main advantage of measuring TNC is that the count is highly reproducible within and among labs, so it can be used accurately throughout the blood banking community. Even better, the TNC count can be automated with the use of a device called a flow cytometer.
At present Colony Forming Units or CFU are considered to be the best measure of whether stem cells are "viable", or quite frankly alive. The TNC count includes both living and dead cells. In the CFU test a small portion is watched under controlled conditions to see if stem cells divide and form colonies. This used to be a subjective measure, but recently it has been standardized with technology to image the cells and count colonies in the image. The only remaining problem with the test is that it takes days for colonies to grow.
- Do I need to store the cord blood in the country where I plan to use it?
No. First, you must store blood in a lab that is permitted by the regulations of the country where you will give birth. Second, you should store cord blood in a lab that can receive and process the collection within 48 hours of birth. After cord blood is collected at birth, the stem cells start to die while the blood is waiting to be processed and frozen. The quicker it gets to the lab the better. By comparison, if you ever need the cord blood for therapy, it will be shipped in a vessel that keeps it frozen. When cord blood is released for therapy can travel to the other side of the world with no loss of viability, because it travels frozen. It is only thawed at the clinic where it will be used.